| CERTBOT(7) | Certbot | CERTBOT(7) |
certbot - Certbot Documentation
NOTE:
Certbot is part of EFF’s effort to encrypt the entire Internet. Secure communication over the Web relies on HTTPS, which requires the use of a digital certificate that lets browsers verify the identity of web servers (e.g., is that really google.com?). Web servers obtain their certificates from trusted third parties called certificate authorities (CAs). Certbot is an easy-to-use client that fetches a certificate from Let’s Encrypt—an open certificate authority launched by the EFF, Mozilla, and others—and deploys it to a web server.
Anyone who has gone through the trouble of setting up a secure website knows what a hassle getting and maintaining a certificate is. Certbot and Let’s Encrypt can automate away the pain and let you turn on and manage HTTPS with simple commands. Using Certbot and Let's Encrypt is free, so there’s no need to arrange payment.
How you use Certbot depends on the configuration of your web server. The best way to get started is to use our interactive guide. It generates instructions based on your configuration settings. In most cases, you’ll need root or administrator access to your web server to run Certbot.
Certbot is meant to be run directly on your web server, not on your personal computer. If you’re using a hosted service and don’t have direct access to your web server, you might not be able to use Certbot. Check with your hosting provider for documentation about uploading certificates or using certificates issued by Let’s Encrypt.
Certbot is a fully-featured, extensible client for the Let's Encrypt CA (or any other CA that speaks the ACME protocol) that can automate the tasks of obtaining certificates and configuring webservers to use them. This client runs on Unix-based operating systems.
To see the changes made to Certbot between versions please refer to our changelog.
If you'd like to contribute to this project please read Developer Guide.
This project is governed by EFF's Public Projects Code of Conduct.
The easiest way to install and run Certbot is by visiting certbot.eff.org, where you can find the correct instructions for many web server and OS combinations. For more information, see Get Certbot.
To understand what the client is doing in detail, it's important to understand the way it uses plugins. Please see the explanation of plugins in the User Guide.
Documentation: https://certbot.eff.org/docs
Software project: https://github.com/certbot/certbot
Notes for developers: https://certbot.eff.org/docs/contributing.html
Main Website: https://certbot.eff.org
Let's Encrypt Website: https://letsencrypt.org
Community: https://community.letsencrypt.org
ACME spec: RFC 8555
ACME working area in github (archived): https://github.com/ietf-wg-acme/acme
See https://certbot.eff.org/docs/install.html#system-requirements.
A public key or digital certificate (formerly called an SSL certificate) uses a public key and a private key to enable secure communication between a client program (web browser, email client, etc.) and a server over an encrypted SSL (secure socket layer) or TLS (transport layer security) connection. The certificate is used both to encrypt the initial stage of communication (secure key exchange) and to identify the server. The certificate includes information about the key, information about the server identity, and the digital signature of the certificate issuer. If the issuer is trusted by the software that initiates the communication, and the signature is valid, then the key can be used to communicate securely with the server identified by the certificate. Using a certificate is a good way to prevent "man-in-the-middle" attacks, in which someone in between you and the server you think you are talking to is able to insert their own (harmful) content.
You can use Certbot to easily obtain and configure a free certificate from Let's Encrypt, a joint project of EFF, Mozilla, and many other sponsors.
Certbot introduces the concept of a lineage, which is a collection of all the versions of a certificate plus Certbot configuration information maintained for that certificate from renewal to renewal. Whenever you renew a certificate, Certbot keeps the same configuration unless you explicitly change it, for example by adding or removing domains. If you add domains, you can either add them to an existing lineage or create a new one.
See also: Re-creating and Updating Existing Certificates
NOTE:
Certbot is meant to be run directly on a web server, normally by a system administrator. In most cases, running Certbot on your personal computer is not a useful option. The instructions below relate to installing and running Certbot on a server.
Unless you have very specific requirements, we kindly suggest that you use the installation instructions for your system found at https://certbot.eff.org/instructions.
Our instructions are the same across all systems that use Snap. You can find instructions for installing Certbot through Snap can be found at https://certbot.eff.org/instructions by selecting your server software and then choosing "snapd" in the "System" dropdown menu.
Most modern Linux distributions (basically any that use systemd) can install Certbot packaged as a snap. Snaps are available for x86_64, ARMv7 and ARMv8 architectures. The Certbot snap provides an easy way to ensure you have the latest version of Certbot with features like automated certificate renewal preconfigured.
If you unable to use snaps, you can use an alternate method for installing certbot.
Docker is an amazingly simple and quick way to obtain a certificate. However, this mode of operation is unable to install certificates or configure your webserver, because our installer plugins cannot reach your webserver from inside the Docker container.
Most users should use the instructions at certbot.eff.org. You should only use Docker if you are sure you know what you are doing and have a good reason to do so.
You should definitely read the Where are my certificates? section, in order to know how to manage the certificates manually. Our ciphersuites page provides some information about recommended ciphersuites. If none of these make much sense to you, you should definitely use the installation method recommended for your system at certbot.eff.org, which enables you to use installer plugins that cover both of those hard topics.
If you're still not convinced and have decided to use this method, from the server that the domain you're requesting a certificate for resolves to, install Docker, then issue a command like the one found below. If you are using Certbot with the Standalone plugin, you will need to make the port it uses accessible from outside of the container by including something like -p 80:80 or -p 443:443 on the command line before certbot/certbot.
sudo docker run -it --rm --name certbot \
-v "/etc/letsencrypt:/etc/letsencrypt" \
-v "/var/lib/letsencrypt:/var/lib/letsencrypt" \
certbot/certbot certonly
Running Certbot with the certonly command will obtain a certificate and place it in the directory /etc/letsencrypt/live on your system. Because Certonly cannot install the certificate from within Docker, you must install the certificate manually according to the procedure recommended by the provider of your webserver.
There are also Docker images for each of Certbot's DNS plugins available at https://hub.docker.com/u/certbot which automate doing domain validation over DNS for popular providers. To use one, just replace certbot/certbot in the command above with the name of the image you want to use. For example, to use Certbot's plugin for Amazon Route 53, you'd use certbot/dns-route53. You may also need to add flags to Certbot and/or mount additional directories to provide access to your DNS API credentials as specified in the DNS plugin documentation.
For more information about the layout of the /etc/letsencrypt directory, see Where are my certificates?.
Installing Certbot through pip is only supported on a best effort basis and when using a virtual environment. Instructions for installing Certbot through pip can be found at https://certbot.eff.org/instructions by selecting your server software and then choosing "pip" in the "System" dropdown menu.
Third party distributions exist for other specific needs. They often are maintained by these parties outside of Certbot and tend to rapidly fall out of date on LTS-style distributions.
We used to have a shell script named certbot-auto to help people install Certbot on UNIX operating systems, however, this script is no longer supported.
Please remove certbot-auto. To do so, you need to do three things:
Certbot uses a number of different commands (also referred to as "subcommands") to request specific actions such as obtaining, renewing, or revoking certificates. The most important and commonly-used commands will be discussed throughout this document; an exhaustive list also appears near the end of the document.
The certbot script on your web server might be named letsencrypt if your system uses an older package. Throughout the docs, whenever you see certbot, swap in the correct name as needed.
Certbot helps you achieve two tasks:
To obtain a certificate and also install it, use the certbot run command (or certbot, which is the same).
To just obtain the certificate without installing it anywhere, the certbot certonly ("certificate only") command can be used.
Some example ways to use Certbot:
# Obtain and install a certificate: certbot # Obtain a certificate but don't install it: certbot certonly # You may specify multiple domains with -d and obtain and # install different certificates by running Certbot multiple times: certbot certonly -d example.com -d www.example.com certbot certonly -d app.example.com -d api.example.com
To perform these tasks, Certbot will ask you to choose from a selection of authenticator and installer plugins. The appropriate choice of plugins will depend on what kind of server software you are running and plan to use your certificates with.
Authenticators are plugins which automatically perform the required steps to prove that you control the domain names you're trying to request a certificate for. An authenticator is always required to obtain a certificate.
Installers are plugins which can automatically modify your web server's configuration to serve your website over HTTPS, using the certificates obtained by Certbot. An installer is only required if you want Certbot to install the certificate to your web server.
Some plugins are both authenticators and installers and it is possible to specify a distinct combination of authenticator and plugin.
| Plugin | Auth | Inst | Notes | Challenge types (and port) |
| apache | Y | Y | Automates obtaining and installing a certificate with Apache. | http-01 (80) |
| nginx | Y | Y | Automates obtaining and installing a certificate with Nginx. | http-01 (80) |
| webroot | Y | N | Obtains a certificate by writing to the webroot directory of an already running webserver. | http-01 (80) |
| standalone | Y | N | Uses a "standalone" webserver to obtain a certificate. Requires port 80 to be available. This is useful on systems with no webserver, or when direct integration with the local webserver is not supported or not desired. | http-01 (80) |
| DNS plugins | Y | N | This category of plugins automates obtaining a certificate by modifying DNS records to prove you have control over a domain. Doing domain validation in this way is the only way to obtain wildcard certificates from Let's Encrypt. | dns-01 (53) |
| manual | Y | N | Obtain a certificate by manually following instructions to perform domain validation yourself. Certificates created this way do not support autorenewal. Autorenewal may be enabled by providing an authentication hook script to automate the domain validation steps. | http-01 (80) or dns-01 (53) |
Under the hood, plugins use one of several ACME protocol challenges to prove you control a domain. The options are http-01 (which uses port 80) and dns-01 (requiring configuration of a DNS server on port 53, though that's often not the same machine as your webserver). A few plugins support more than one challenge type, in which case you can choose one with --preferred-challenges.
There are also many third-party-plugins available. Below we describe in more detail the circumstances in which each plugin can be used, and how to use it.
The Apache plugin currently supports modern OSes based on Debian, Fedora, SUSE, Gentoo, CentOS and Darwin. This automates both obtaining and installing certificates on an Apache webserver. To specify this plugin on the command line, simply include --apache.
If you're running a local webserver for which you have the ability to modify the content being served, and you'd prefer not to stop the webserver during the certificate issuance process, you can use the webroot plugin to obtain a certificate by including certonly and --webroot on the command line. In addition, you'll need to specify --webroot-path or -w with the top-level directory ("web root") containing the files served by your webserver. For example, --webroot-path /var/www/html or --webroot-path /usr/share/nginx/html are two common webroot paths.
If you're getting a certificate for many domains at once, the plugin needs to know where each domain's files are served from, which could potentially be a separate directory for each domain. When requesting a certificate for multiple domains, each domain will use the most recently specified --webroot-path. So, for instance,
certbot certonly --webroot -w /var/www/example -d www.example.com -d example.com -w /var/www/other -d other.example.net -d another.other.example.net
would obtain a single certificate for all of those names, using the /var/www/example webroot directory for the first two, and /var/www/other for the second two.
The webroot plugin works by creating a temporary file for each of your requested domains in ${webroot-path}/.well-known/acme-challenge. Then the Let's Encrypt validation server makes HTTP requests to validate that the DNS for each requested domain resolves to the server running certbot. An example request made to your web server would look like:
66.133.109.36 - - [05/Jan/2016:20:11:24 -0500] "GET /.well-known/acme-challenge/HGr8U1IeTW4kY_Z6UIyaakzOkyQgPr_7ArlLgtZE8SX HTTP/1.1" 200 87 "-" "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)"
Note that to use the webroot plugin, your server must be configured to serve files from hidden directories. If /.well-known is treated specially by your webserver configuration, you might need to modify the configuration to ensure that files inside /.well-known/acme-challenge are served by the webserver.
Under Windows, Certbot will generate a web.config file, if one does not already exist, in /.well-known/acme-challenge in order to let IIS serve the challenge files even if they do not have an extension.
The Nginx plugin should work for most configurations. We recommend backing up Nginx configurations before using it (though you can also revert changes to configurations with certbot --nginx rollback). You can use it by providing the --nginx flag on the commandline.
certbot --nginx
Use standalone mode to obtain a certificate if you don't want to use (or don't currently have) existing server software. The standalone plugin does not rely on any other server software running on the machine where you obtain the certificate.
To obtain a certificate using a "standalone" webserver, you can use the standalone plugin by including certonly and --standalone on the command line. This plugin needs to bind to port 80 in order to perform domain validation, so you may need to stop your existing webserver.
It must still be possible for your machine to accept inbound connections from the Internet on the specified port using each requested domain name.
By default, Certbot first attempts to bind to the port for all interfaces using IPv6 and then bind to that port using IPv4; Certbot continues so long as at least one bind succeeds. On most Linux systems, IPv4 traffic will be routed to the bound IPv6 port and the failure during the second bind is expected.
Use --<challenge-type>-address to explicitly tell Certbot which interface (and protocol) to bind.
If you'd like to obtain a wildcard certificate from Let's Encrypt or run certbot on a machine other than your target webserver, you can use one of Certbot's DNS plugins.
These plugins are not included in a default Certbot installation and must be installed separately. They are available in many OS package managers, as Docker images, and as snaps. Visit https://certbot.eff.org to learn the best way to use the DNS plugins on your system.
Once installed, you can find documentation on how to use each plugin at:
If you'd like to obtain a certificate running certbot on a machine other than your target webserver or perform the steps for domain validation yourself, you can use the manual plugin. While hidden from the UI, you can use the plugin to obtain a certificate by specifying certonly and --manual on the command line. This requires you to copy and paste commands into another terminal session, which may be on a different computer.
The manual plugin can use either the http or the dns challenge. You can use the --preferred-challenges option to choose the challenge of your preference.
The http challenge will ask you to place a file with a specific name and specific content in the /.well-known/acme-challenge/ directory directly in the top-level directory (“web root”) containing the files served by your webserver. In essence it's the same as the webroot plugin, but not automated.
When using the dns challenge, certbot will ask you to place a TXT DNS record with specific contents under the domain name consisting of the hostname for which you want a certificate issued, prepended by _acme-challenge.
For example, for the domain example.com, a zone file entry would look like:
_acme-challenge.example.com. 300 IN TXT "gfj9Xq...Rg85nM"
Renewal with the manual plugin
Certificates created using --manual do not support automatic renewal unless combined with an authentication hook script via --manual-auth-hook to automatically set up the required HTTP and/or TXT challenges.
If you can use one of the other plugins which support autorenewal to create your certificate, doing so is highly recommended.
To manually renew a certificate using --manual without hooks, repeat the same certbot --manual command you used to create the certificate originally. As this will require you to copy and paste new HTTP files or DNS TXT records, the command cannot be automated with a cron job.
Sometimes you may want to specify a combination of distinct authenticator and installer plugins. To do so, specify the authenticator plugin with --authenticator or -a and the installer plugin with --installer or -i.
For instance, you could create a certificate using the webroot plugin for authentication and the apache plugin for installation.
certbot run -a webroot -i apache -w /var/www/html -d example.com
Or you could create a certificate using the manual plugin for authentication and the nginx plugin for installation. (Note that this certificate cannot be renewed automatically.)
certbot run -a manual -i nginx -d example.com
There are also a number of third-party plugins for the client, provided by other developers. Many are beta/experimental, but some are already in widespread use:
| Plugin | Auth | Inst | Notes |
| haproxy | Y | Y | Integration with the HAProxy load balancer |
| s3front | Y | Y | Integration with Amazon CloudFront distribution of S3 buckets |
| gandi | Y | N | Obtain certificates via the Gandi LiveDNS API |
| varnish | Y | N | Obtain certificates via a Varnish server |
| external-auth | Y | Y | A plugin for convenient scripting |
| pritunl | N | Y | Install certificates in pritunl distributed OpenVPN servers |
| proxmox | N | Y | Install certificates in Proxmox Virtualization servers |
| dns-standalone | Y | N | Obtain certificates via an integrated DNS server |
| dns-ispconfig | Y | N | DNS Authentication using ISPConfig as DNS server |
| dns-clouddns | Y | N | DNS Authentication using CloudDNS API |
| dns-lightsail | Y | N | DNS Authentication using Amazon Lightsail DNS API |
| dns-inwx | Y | Y | DNS Authentication for INWX through the XML API |
| dns-azure | Y | N | DNS Authentication using Azure DNS |
| dns-godaddy | Y | N | DNS Authentication using Godaddy DNS |
| dns-yandexcloud | Y | N | DNS Authentication using Yandex Cloud DNS |
| dns-bunny | Y | N | DNS Authentication using BunnyDNS |
| njalla | Y | N | DNS Authentication for njalla |
| DuckDNS | Y | N | DNS Authentication for DuckDNS |
| Porkbun | Y | N | DNS Authentication for Porkbun |
| Infomaniak | Y | N | DNS Authentication using Infomaniak Domains API |
| dns-multi | Y | N | DNS authentication of 100+ providers using go-acme/lego |
If you're interested, you can also write your own plugin.
To view a list of the certificates Certbot knows about, run the certificates subcommand:
certbot certificates
This returns information in the following format:
Found the following certificates:
Certificate Name: example.com
Domains: example.com, www.example.com
Expiry Date: 2017-02-19 19:53:00+00:00 (VALID: 30 days)
Certificate Path: /etc/letsencrypt/live/example.com/fullchain.pem
Key Type: RSA
Private Key Path: /etc/letsencrypt/live/example.com/privkey.pem
Certificate Name shows the name of the certificate. Pass this name using the --cert-name flag to specify a particular certificate for the run, certonly, certificates, renew, and delete commands. Example:
certbot certonly --cert-name example.com
You can use certonly or run subcommands to request the creation of a single new certificate even if you already have an existing certificate with some of the same domain names.
If a certificate is requested with run or certonly specifying a certificate name that already exists, Certbot updates the existing certificate. Otherwise a new certificate is created and assigned the specified name.
The --force-renewal, --duplicate, and --expand options control Certbot's behavior when re-creating a certificate with the same name as an existing certificate. If you don't specify a requested behavior, Certbot may ask you what you intended.
--force-renewal tells Certbot to request a new certificate with the same domains as an existing certificate. Each domain must be explicitly specified via -d. If successful, this certificate is saved alongside the earlier one and symbolic links (the "live" reference) will be updated to point to the new certificate. This is a valid method of renewing a specific individual certificate.
--duplicate tells Certbot to create a separate, unrelated certificate with the same domains as an existing certificate. This certificate is saved completely separately from the prior one. Most users will not need to issue this command in normal circumstances.
--expand tells Certbot to update an existing certificate with a new certificate that contains all of the old domains and one or more additional new domains. With the --expand option, use the -d option to specify all existing domains and one or more new domains.
Example:
certbot --expand -d existing.com,example.com,newdomain.com
If you prefer, you can specify the domains individually like this:
certbot --expand -d existing.com -d example.com -d newdomain.com
Consider using --cert-name instead of --expand, as it gives more control over which certificate is modified and it lets you remove domains as well as adding them.
--allow-subset-of-names tells Certbot to continue with certificate generation if only some of the specified domain authorizations can be obtained. This may be useful if some domains specified in a certificate no longer point at this system.
Whenever you obtain a new certificate in any of these ways, the new certificate exists alongside any previously obtained certificates, whether or not the previous certificates have expired. The generation of a new certificate counts against several rate limits that are intended to prevent abuse of the ACME protocol, as described here.
The --cert-name flag can also be used to modify the domains a certificate contains, by specifying new domains using the -d or --domains flag. If certificate example.com previously contained example.com and www.example.com, it can be modified to only contain example.com by specifying only example.com with the -d or --domains flag. Example:
certbot certonly --cert-name example.com -d example.com
The same format can be used to expand the set of domains a certificate contains, or to replace that set entirely:
certbot certonly --cert-name example.com -d example.org,www.example.org
Certbot supports two certificate private key algorithms: rsa and ecdsa.
As of version 2.0.0, Certbot defaults to ECDSA secp256r1 (P-256) certificate private keys for all new certificates. Existing certificates will continue to renew using their existing key type, unless a key type change is requested.
The type of key used by Certbot can be controlled through the --key-type option. You can use the --elliptic-curve option to control the curve used in ECDSA certificates and the --rsa-key-size option to control the size of RSA keys.
WARNING:
Unless you are aware that you need to support very old HTTPS clients that are not supported by most sites, you can safely transition your site to use ECDSA keys instead of RSA keys.
If you want to change a single certificate to use ECDSA keys, you'll need to create or renew a certificate while setting --key-type ecdsa on the command line:
certbot renew --key-type ecdsa --cert-name example.com --force-renewal
If you want to use ECDSA keys for all certificates in the future (including renewals of existing certificates), you can add the following line to Certbot's configuration file:
key-type = ecdsa
which will take effect upon the next renewal of each certificate.
If you need to revoke a certificate, use the revoke subcommand to do so.
A certificate may be revoked by providing its name (see certbot certificates) or by providing its path directly:
certbot revoke --cert-name example.com certbot revoke --cert-path /etc/letsencrypt/live/example.com/cert.pem
If the certificate being revoked was obtained via the --staging, --test-cert or a non-default --server flag, that flag must be passed to the revoke subcommand.
NOTE:
You can also specify the reason for revoking your certificate by using the reason flag. Reasons include unspecified which is the default, as well as keycompromise, affiliationchanged, superseded, and cessationofoperation:
certbot revoke --cert-name example.com --reason keycompromise
By default, Certbot will try revoke the certificate using your ACME account key. If the certificate was created from the same ACME account, the revocation will be successful.
If you instead have the corresponding private key file to the certificate you wish to revoke, use --key-path to perform the revocation from any ACME account:
certbot revoke --cert-path /etc/letsencrypt/live/example.com/cert.pem --key-path /etc/letsencrypt/live/example.com/privkey.pem
If you need to delete a certificate, use the delete subcommand.
NOTE:
Certbot does not automatically revoke a certificate before deleting it. If you're no longer using a certificate and don't plan to use it anywhere else, you may want to follow the instructions in Revoking certificates instead. Generally, there's no need to revoke a certificate if its private key has not been compromised, but you may still receive expiration emails from Let's Encrypt unless you revoke.
NOTE:
A certificate may be deleted by providing its name with --cert-name. You may find its name using certbot certificates.
Otherwise, you will be prompted to choose one or more certificates to delete:
certbot delete --cert-name example.com # or to choose from a list: certbot delete
Deleting a certificate without following the proper steps can result in a non-functioning server. To safely delete a certificate, follow all the steps below to make sure that references to a certificate are removed from the configuration of any installed server software (Apache, nginx, Postfix, etc) before deleting the certificate.
To explain further, when installing a certificate, Certbot modifies Apache or nginx's configuration to load the certificate and its private key from the /etc/letsencrypt/live/ directory. Before deleting a certificate, it is necessary to undo that modification, by removing any references to the certificate from the webserver's configuration files.
Follow these steps to safely delete a certificate:
sudo bash -c 'grep -R live/example.com /etc/{nginx,httpd,apache2}'
If there are no references found, skip directly to Step 4.
If some references are found, they will look something like:
/etc/apache2/sites-available/000-default-le-ssl.conf:SSLCertificateFile /etc/letsencrypt/live/example.com/fullchain.pem /etc/apache2/sites-available/000-default-le-ssl.conf:SSLCertificateKeyFile /etc/letsencrypt/live/example.com/privkey.pem
sudo openssl req -nodes -batch -x509 -newkey rsa:2048 -keyout /etc/letsencrypt/self-signed-privkey.pem -out /etc/letsencrypt/self-signed-cert.pem -days 356
Continuing from the previous example, you would open /etc/apache2/sites-available/000-default-le-ssl.conf in a text editor and modify the two matching lines of text to instead say:
SSLCertificateFile /etc/letsencrypt/self-signed-cert.pem SSLCertificateKeyFile /etc/letsencrypt/self-signed-privkey.pem
sudo certbot delete --cert-name example.com
NOTE:
SEE ALSO:
SEE ALSO:
As of version 0.10.0, Certbot supports a renew action to check all installed certificates for impending expiry and attempt to renew them. The simplest form is simply
certbot renew
This command attempts to renew any previously-obtained certificates that expire in less than 30 days. The same plugin and options that were used at the time the certificate was originally issued will be used for the renewal attempt, unless you specify other plugins or options. Unlike certonly, renew acts on multiple certificates and always takes into account whether each one is near expiry. Because of this, renew is suitable (and designed) for automated use, to allow your system to automatically renew each certificate when appropriate. Since renew only renews certificates that are near expiry it can be run as frequently as you want - since it will usually take no action.
The renew command includes hooks for running commands or scripts before or after a certificate is renewed. For example, if you have a single certificate obtained using the standalone plugin, you might need to stop the webserver before renewing so standalone can bind to the necessary ports, and then restart it after the plugin is finished. Example:
certbot renew --pre-hook "service nginx stop" --post-hook "service nginx start"
If a hook exits with a non-zero exit code, the error will be printed to stderr but renewal will be attempted anyway. A failing hook doesn't directly cause Certbot to exit with a non-zero exit code, but since Certbot exits with a non-zero exit code when renewals fail, a failed hook causing renewal failures will indirectly result in a non-zero exit code. Hooks will only be run if a certificate is due for renewal, so you can run the above command frequently without unnecessarily stopping your webserver.
When Certbot detects that a certificate is due for renewal, --pre-hook and --post-hook hooks run before and after each attempt to renew it. If you want your hook to run only after a successful renewal, use --deploy-hook in a command like this.
certbot renew --deploy-hook /path/to/deploy-hook-script
You can also specify hooks by placing files in subdirectories of Certbot's configuration directory. Assuming your configuration directory is /etc/letsencrypt, any executable files found in /etc/letsencrypt/renewal-hooks/pre, /etc/letsencrypt/renewal-hooks/deploy, and /etc/letsencrypt/renewal-hooks/post will be run as pre, deploy, and post hooks respectively when any certificate is renewed with the renew subcommand. These hooks are run in alphabetical order and are not run for other subcommands. (The order the hooks are run is determined by the byte value of the characters in their filenames and is not dependent on your locale.)
Hooks specified in the command line, configuration file, or renewal configuration files are run as usual after running all hooks in these directories. One minor exception to this is if a hook specified elsewhere is simply the path to an executable file in the hook directory of the same type (e.g. your pre-hook is the path to an executable in /etc/letsencrypt/renewal-hooks/pre), the file is not run a second time. You can stop Certbot from automatically running executables found in these directories by including --no-directory-hooks on the command line.
More information about hooks can be found by running certbot --help renew.
If you're sure that this command executes successfully without human intervention, you can add the command to crontab (since certificates are only renewed when they're determined to be near expiry, the command can run on a regular basis, like every week or every day). In that case, you are likely to want to use the -q or --quiet quiet flag to silence all output except errors.
If you are manually renewing all of your certificates, the --force-renewal flag may be helpful; it causes the expiration time of the certificate(s) to be ignored when considering renewal, and attempts to renew each and every installed certificate regardless of its age. (This form is not appropriate to run daily because each certificate will be renewed every day, which will quickly run into the certificate authority rate limit.)
Note that options provided to certbot renew will apply to every certificate for which renewal is attempted; for example, certbot renew --rsa-key-size 4096 would try to replace every near-expiry certificate with an equivalent certificate using a 4096-bit RSA public key. If a certificate is successfully renewed using specified options, those options will be saved and used for future renewals of that certificate.
An alternative form that provides for more fine-grained control over the renewal process (while renewing specified certificates one at a time), is certbot certonly with the complete set of subject domains of a specific certificate specified via -d flags. You may also want to include the -n or --noninteractive flag to prevent blocking on user input (which is useful when running the command from cron).
certbot certonly -n -d example.com -d www.example.com
All of the domains covered by the certificate must be specified in this case in order to renew and replace the old certificate rather than obtaining a new one; don't forget any www. domains! Specifying a subset of the domains creates a new, separate certificate containing only those domains, rather than replacing the original certificate. When run with a set of domains corresponding to an existing certificate, the certonly command attempts to renew that specific certificate.
Please note that the CA will send notification emails to the address you provide if you do not renew certificates that are about to expire.
Certbot is working hard to improve the renewal process, and we apologize for any inconvenience you encounter in integrating these commands into your individual environment.
NOTE:
When creating a certificate, Certbot will keep track of all of the relevant options chosen by the user. At renewal time, Certbot will remember these options and apply them once again.
Sometimes, you may encounter the need to change some of these options for future certificate renewals. To achieve this, you will need to perform the following steps:
NOTE:
As a practical example, if you were using the webroot authenticator and had relocated your website to another directory, you would need to change the --webroot-path to the new directory. Following the above advice:
certbot renew --cert-name example.com --webroot-path /path/to/new/location --dry-run
certbot renew --cert-name example.com --webroot-path /path/to/new/location --force-renewal
--cert-name selects the particular certificate to be modified. Without this option, all certificates will be selected.
--webroot-path is the option intended to be changed. All other previously selected options will be kept the same and do not need to be included in the command.
For advanced certificate management tasks, it is also possible to manually modify the certificate's renewal configuration file, but this is discouraged since it can easily break Certbot's ability to renew your certificates. These renewal configuration files are located at /etc/letsencrypt/renewal/CERTNAME.conf. If you choose to modify the renewal configuration file we advise you to make a backup of the file beforehand and test its validity with the certbot renew --dry-run command.
WARNING:
Most Certbot installations come with automatic renewals preconfigured. This is done by means of a scheduled task which runs certbot renew periodically.
If you are unsure whether you need to configure automated renewal:
If you think you may need to set up automated renewal, follow these instructions to set up a scheduled task to automatically renew your certificates in the background. If you are unsure whether your system has a pre-installed scheduled task for Certbot, it is safe to follow these instructions to create one.
NOTE:
If you are using macOS and installed Certbot using Homebrew, follow the instructions at https://certbot.eff.org/instructions to set up automated renewal. The instructions below are not applicable on macOS.
Run the following line, which will add a cron job to /etc/crontab:
SLEEPTIME=$(awk 'BEGIN{srand(); print int(rand()*(3600+1))}'); echo "0 0,12 * * * root sleep $SLEEPTIME && certbot renew -q" | sudo tee -a /etc/crontab > /dev/null
If you needed to stop your webserver to run Certbot, you'll want to add pre and post hooks to stop and start your webserver automatically. For example, if your webserver is HAProxy, run the following commands to create the hook files in the appropriate directory:
sudo sh -c 'printf "#!/bin/sh\nservice haproxy stop\n" > /etc/letsencrypt/renewal-hooks/pre/haproxy.sh' sudo sh -c 'printf "#!/bin/sh\nservice haproxy start\n" > /etc/letsencrypt/renewal-hooks/post/haproxy.sh' sudo chmod 755 /etc/letsencrypt/renewal-hooks/pre/haproxy.sh sudo chmod 755 /etc/letsencrypt/renewal-hooks/post/haproxy.sh
Congratulations, Certbot will now automatically renew your certificates in the background.
If you are interested in learning more about how Certbot renews your certificates, see the Renewing certificates section above.
All generated keys and issued certificates can be found in /etc/letsencrypt/live/$domain, where $domain is the certificate name (see the note below). Rather than copying, please point your (web) server configuration directly to those files (or create symlinks). During the renewal, /etc/letsencrypt/live is updated with the latest necessary files.
NOTE:
For historical reasons, the containing directories are created with permissions of 0700 meaning that certificates are accessible only to servers that run as the root user. If you will never downgrade to an older version of Certbot, then you can safely fix this using chmod 0755 /etc/letsencrypt/{live,archive}.
For servers that drop root privileges before attempting to read the private key file, you will also need to use chgrp and chmod 0640 to allow the server to read /etc/letsencrypt/live/$domain/privkey.pem.
NOTE:
The following files are available:
WARNING:
NOTE:
This is what Apache needs for SSLCertificateKeyFile, and Nginx for ssl_certificate_key.
This is what Apache >= 2.4.8 needs for SSLCertificateFile, and what Nginx needs for ssl_certificate.
Apache < 2.4.8 needs these for SSLCertificateFile. and SSLCertificateChainFile, respectively.
If you're using OCSP stapling with Nginx >= 1.3.7, chain.pem should be provided as the ssl_trusted_certificate to validate OCSP responses.
NOTE:
Certbot allows for the specification of pre and post validation hooks when run in manual mode. The flags to specify these scripts are --manual-auth-hook and --manual-cleanup-hook respectively and can be used as follows:
certbot certonly --manual --manual-auth-hook /path/to/http/authenticator.sh --manual-cleanup-hook /path/to/http/cleanup.sh -d secure.example.com
This will run the authenticator.sh script, attempt the validation, and then run the cleanup.sh script. Additionally certbot will pass relevant environment variables to these scripts:
Additionally for cleanup:
Example usage for HTTP-01:
certbot certonly --manual --preferred-challenges=http --manual-auth-hook /path/to/http/authenticator.sh --manual-cleanup-hook /path/to/http/cleanup.sh -d secure.example.com
/path/to/http/authenticator.sh
#!/bin/bash echo $CERTBOT_VALIDATION > /var/www/htdocs/.well-known/acme-challenge/$CERTBOT_TOKEN
/path/to/http/cleanup.sh
#!/bin/bash rm -f /var/www/htdocs/.well-known/acme-challenge/$CERTBOT_TOKEN
Example usage for DNS-01 (Cloudflare API v4) (for example purposes only, do not use as-is)
certbot certonly --manual --preferred-challenges=dns --manual-auth-hook /path/to/dns/authenticator.sh --manual-cleanup-hook /path/to/dns/cleanup.sh -d secure.example.com
/path/to/dns/authenticator.sh
#!/bin/bash # Get your API key from https://www.cloudflare.com/a/account/my-account API_KEY="your-api-key" EMAIL="your.email@example.com" # Strip only the top domain to get the zone id DOMAIN=$(expr match "$CERTBOT_DOMAIN" '.*\.\(.*\..*\)') # Get the Cloudflare zone id ZONE_EXTRA_PARAMS="status=active&page=1&per_page=20&order=status&direction=desc&match=all" ZONE_ID=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$DOMAIN&$ZONE_EXTRA_PARAMS" \
-H "X-Auth-Email: $EMAIL" \
-H "X-Auth-Key: $API_KEY" \
-H "Content-Type: application/json" | python -c "import sys,json;print(json.load(sys.stdin)['result'][0]['id'])") # Create TXT record CREATE_DOMAIN="_acme-challenge.$CERTBOT_DOMAIN" RECORD_ID=$(curl -s -X POST "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records" \
-H "X-Auth-Email: $EMAIL" \
-H "X-Auth-Key: $API_KEY" \
-H "Content-Type: application/json" \
--data '{"type":"TXT","name":"'"$CREATE_DOMAIN"'","content":"'"$CERTBOT_VALIDATION"'","ttl":120}' \
| python -c "import sys,json;print(json.load(sys.stdin)['result']['id'])") # Save info for cleanup if [ ! -d /tmp/CERTBOT_$CERTBOT_DOMAIN ];then
mkdir -m 0700 /tmp/CERTBOT_$CERTBOT_DOMAIN fi echo $ZONE_ID > /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID echo $RECORD_ID > /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID # Sleep to make sure the change has time to propagate over to DNS sleep 25
/path/to/dns/cleanup.sh
#!/bin/bash # Get your API key from https://www.cloudflare.com/a/account/my-account API_KEY="your-api-key" EMAIL="your.email@example.com" if [ -f /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID ]; then
ZONE_ID=$(cat /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID)
rm -f /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID fi if [ -f /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID ]; then
RECORD_ID=$(cat /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID)
rm -f /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID fi # Remove the challenge TXT record from the zone if [ -n "${ZONE_ID}" ]; then
if [ -n "${RECORD_ID}" ]; then
curl -s -X DELETE "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records/$RECORD_ID" \
-H "X-Auth-Email: $EMAIL" \
-H "X-Auth-Key: $API_KEY" \
-H "Content-Type: application/json"
fi fi
By default, Certbot uses Let's Encrypt's production server at https://acme-v02.api.letsencrypt.org/directory. You can tell Certbot to use a different CA by providing --server on the command line or in a configuration file with the URL of the server's ACME directory. For example, if you would like to use Let's Encrypt's staging server, you would add --server https://acme-staging-v02.api.letsencrypt.org/directory to the command line.
If Certbot does not trust the SSL certificate used by the ACME server, you can use the REQUESTS_CA_BUNDLE environment variable to override the root certificates trusted by Certbot. Certbot uses the requests library, which does not use the operating system trusted root store.
If you use --server to specify an ACME CA that implements the standardized version of the spec, you may be able to obtain a certificate for a wildcard domain. Some CAs (such as Let's Encrypt) require that domain validation for wildcard domains must be done through modifications to DNS records which means that the dns-01 challenge type must be used. To see a list of Certbot plugins that support this challenge type and how to use them, see plugins.
When processing a validation Certbot writes a number of lock files on your system to prevent multiple instances from overwriting each other's changes. This means that by default two instances of Certbot will not be able to run in parallel.
Since the directories used by Certbot are configurable, Certbot will write a lock file for all of the directories it uses. This include Certbot's --work-dir, --logs-dir, and --config-dir. By default these are /var/lib/letsencrypt, /var/log/letsencrypt, and /etc/letsencrypt respectively. Additionally if you are using Certbot with Apache or nginx it will lock the configuration folder for that program, which are typically also in the /etc directory.
Note that these lock files will only prevent other instances of Certbot from using those directories, not other processes. If you'd like to run multiple instances of Certbot simultaneously you should specify different directories as the --work-dir, --logs-dir, and --config-dir for each instance of Certbot that you would like to run.
Certbot accepts a global configuration file that applies its options to all invocations of Certbot. Certificate specific configuration choices should be set in the .conf files that can be found in /etc/letsencrypt/renewal.
By default no cli.ini file is created (though it may exist already if you installed Certbot via a package manager, for instance). After creating one it is possible to specify the location of this configuration file with certbot --config cli.ini (or shorter -c cli.ini). An example configuration file is shown below:
# This is an example of the kind of things you can do in a configuration file. # All flags used by the client can be configured here. Run Certbot with # "--help" to learn more about the available options. # # Note that these options apply automatically to all use of Certbot for # obtaining or renewing certificates, so options specific to a single # certificate on a system with several certificates should not be placed # here. # Use ECC for the private key key-type = ecdsa elliptic-curve = secp384r1 # Use a 4096 bit RSA key instead of 2048 rsa-key-size = 4096 # Uncomment and update to register with the specified e-mail address # email = foo@example.com # Uncomment to use the standalone authenticator on port 443 # authenticator = standalone # Uncomment to use the webroot authenticator. Replace webroot-path with the # path to the public_html / webroot folder being served by your web server. # authenticator = webroot # webroot-path = /usr/share/nginx/html # Uncomment to automatically agree to the terms of service of the ACME server # agree-tos = true # An example of using an alternate ACME server that uses EAB credentials # server = https://acme.sectigo.com/v2/InCommonRSAOV # eab-kid = somestringofstuffwithoutquotes # eab-hmac-key = yaddayaddahexhexnotquoted
By default, the following locations are searched:
Since this configuration file applies to all invocations of certbot it is incorrect to list domains in it. Listing domains in cli.ini may prevent renewal from working. Additionally due to how arguments in cli.ini are parsed, options which wish to not be set should not be listed. Options set to false will instead be read as being set to true by older versions of Certbot, since they have been listed in the config file.
By default certbot stores status logs in /var/log/letsencrypt. By default certbot will begin rotating logs once there are 1000 logs in the log directory. Meaning that once 1000 files are in /var/log/letsencrypt Certbot will delete the oldest one to make room for new logs. The number of subsequent logs can be changed by passing the desired number to the command line flag --max-log-backups. Setting this flag to 0 disables log rotation entirely, causing certbot to always append to the same log file.
NOTE:
Certbot supports a lot of command line options. Here's the full list, from certbot --help all:
usage:
certbot [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ... Certbot can obtain and install HTTPS/TLS/SSL certificates. By default, it will attempt to use a webserver both for obtaining and installing the certificate. The most common SUBCOMMANDS and flags are: obtain, install, and renew certificates:
(default) run Obtain & install a certificate in your current webserver
certonly Obtain or renew a certificate, but do not install it
renew Renew all previously obtained certificates that are near expiry
enhance Add security enhancements to your existing configuration
-d DOMAINS Comma-separated list of domains to obtain a certificate for
--apache Use the Apache plugin for authentication & installation
--standalone Run a standalone webserver for authentication
--nginx Use the Nginx plugin for authentication & installation
--webroot Place files in a server's webroot folder for authentication
--manual Obtain certificates interactively, or using shell script hooks
-n Run non-interactively
--test-cert Obtain a test certificate from a staging server
--dry-run Test "renew" or "certonly" without saving any certificates to disk manage certificates:
certificates Display information about certificates you have from Certbot
revoke Revoke a certificate (supply --cert-name or --cert-path)
delete Delete a certificate (supply --cert-name) manage your account:
register Create an ACME account
unregister Deactivate an ACME account
update_account Update an ACME account
show_account Display account details
--agree-tos Agree to the ACME server's Subscriber Agreement
-m EMAIL Email address for important account notifications options:
-h, --help show this help message and exit
-c CONFIG_FILE, --config CONFIG_FILE
path to config file (default: /etc/letsencrypt/cli.ini
and ~/.config/letsencrypt/cli.ini)
-v, --verbose This flag can be used multiple times to incrementally
increase the verbosity of output, e.g. -vvv. (default:
0)
--max-log-backups MAX_LOG_BACKUPS
Specifies the maximum number of backup logs that
should be kept by Certbot's built in log rotation.
Setting this flag to 0 disables log rotation entirely,
causing Certbot to always append to the same log file.
(default: 1000)
-n, --non-interactive, --noninteractive
Run without ever asking for user input. This may
require additional command line flags; the client will
try to explain which ones are required if it finds one
missing (default: False)
--force-interactive Force Certbot to be interactive even if it detects
it's not being run in a terminal. This flag cannot be
used with the renew subcommand. (default: False)
-d DOMAIN, --domains DOMAIN, --domain DOMAIN
Domain names to apply. For multiple domains you can
use multiple -d flags or enter a comma separated list
of domains as a parameter. The first domain provided
will be the subject CN of the certificate, and all
domains will be Subject Alternative Names on the
certificate. The first domain will also be used in
some software user interfaces and as the file paths
for the certificate and related material unless
otherwise specified or you already have a certificate
with the same name. In the case of a name collision it
will append a number like 0001 to the file path name.
(default: Ask)
--eab-kid EAB_KID Key Identifier for External Account Binding (default:
None)
--eab-hmac-key EAB_HMAC_KEY
HMAC key for External Account Binding (default: None)
--cert-name CERTNAME Certificate name to apply. This name is used by
Certbot for housekeeping and in file paths; it doesn't
affect the content of the certificate itself. To see
certificate names, run 'certbot certificates'. When
creating a new certificate, specifies the new
certificate's name. (default: the first provided
domain or the name of an existing certificate on your
system for the same domains)
--dry-run Perform a test run of the client, obtaining test
(invalid) certificates but not saving them to disk.
This can currently only be used with the 'certonly'
and 'renew' subcommands. Note: Although --dry-run
tries to avoid making any persistent changes on a
system, it is not completely side-effect free: if used
with webserver authenticator plugins like apache and
nginx, it makes and then reverts temporary config
changes in order to obtain test certificates, and
reloads webservers to deploy and then roll back those
changes. It also calls --pre-hook and --post-hook
commands if they are defined because they may be
necessary to accurately simulate renewal. --deploy-
hook commands are not called. (default: False)
--debug-challenges After setting up challenges, wait for user input
before submitting to CA. When used in combination with
the `-v` option, the challenge URLs or FQDNs and their
expected return values are shown. (default: False)
--preferred-chain PREFERRED_CHAIN
Set the preferred certificate chain. If the CA offers
multiple certificate chains, prefer the chain whose
topmost certificate was issued from this Subject
Common Name. If no match, the default offered chain
will be used. (default: None)
--preferred-challenges PREF_CHALLS
A sorted, comma delimited list of the preferred
challenge to use during authorization with the most
preferred challenge listed first (Eg, "dns" or
"http,dns"). Not all plugins support all challenges.
See https://certbot.eff.org/docs/using.html#plugins
for details. ACME Challenges are versioned, but if you
pick "http" rather than "http-01", Certbot will select
the latest version automatically. (default: [])
--issuance-timeout ISSUANCE_TIMEOUT
This option specifies how long (in seconds) Certbot
will wait for the server to issue a certificate.
(default: 90)
--user-agent USER_AGENT
Set a custom user agent string for the client. User
agent strings allow the CA to collect high level
statistics about success rates by OS, plugin and use
case, and to know when to deprecate support for past
Python versions and flags. If you wish to hide this
information from the Let's Encrypt server, set this to
"". (default: CertbotACMEClient/2.0.0 (certbot;
OS_NAME OS_VERSION) Authenticator/XXX Installer/YYY
(SUBCOMMAND; flags: FLAGS) Py/major.minor.patchlevel).
The flags encoded in the user agent are: --duplicate,
--force-renew, --allow-subset-of-names, -n, and
whether any hooks are set.
--user-agent-comment USER_AGENT_COMMENT
Add a comment to the default user agent string. May be
used when repackaging Certbot or calling it from
another tool to allow additional statistical data to
be collected. Ignored if --user-agent is set.
(Example: Foo-Wrapper/1.0) (default: None) automation:
Flags for automating execution & other tweaks
--keep-until-expiring, --keep, --reinstall
If the requested certificate matches an existing
certificate, always keep the existing one until it is
due for renewal (for the 'run' subcommand this means
reinstall the existing certificate). (default: Ask)
--expand If an existing certificate is a strict subset of the
requested names, always expand and replace it with the
additional names. (default: Ask)
--version show program's version number and exit
--force-renewal, --renew-by-default
If a certificate already exists for the requested
domains, renew it now, regardless of whether it is
near expiry. (Often --keep-until-expiring is more
appropriate). Also implies --expand. (default: False)
--renew-with-new-domains
If a certificate already exists for the requested
certificate name but does not match the requested
domains, renew it now, regardless of whether it is
near expiry. (default: False)
--reuse-key When renewing, use the same private key as the
existing certificate. (default: False)
--no-reuse-key When renewing, do not use the same private key as the
existing certificate. Not reusing private keys is the
default behavior of Certbot. This option may be used
to unset --reuse-key on an existing certificate.
(default: False)
--new-key When renewing or replacing a certificate, generate a
new private key, even if --reuse-key is set on the
existing certificate. Combining --new-key and --reuse-
key will result in the private key being replaced and
then reused in future renewals. (default: False)
--allow-subset-of-names
When performing domain validation, do not consider it
a failure if authorizations can not be obtained for a
strict subset of the requested domains. This may be
useful for allowing renewals for multiple domains to
succeed even if some domains no longer point at this
system. This option cannot be used with --csr.
(default: False)
--agree-tos Agree to the ACME Subscriber Agreement (default: Ask)
--duplicate Allow making a certificate lineage that duplicates an
existing one (both can be renewed in parallel)
(default: False)
-q, --quiet Silence all output except errors. Useful for
automation via cron. Implies --non-interactive.
(default: False) security:
Security parameters & server settings
--rsa-key-size N Size of the RSA key. (default: 2048)
--key-type {rsa,ecdsa}
Type of generated private key. Only *ONE* per
invocation can be provided at this time. (default:
ecdsa)
--elliptic-curve N The SECG elliptic curve name to use. Please see RFC
8446 for supported values. (default: secp256r1)
--must-staple Adds the OCSP Must-Staple extension to the
certificate. Autoconfigures OCSP Stapling for
supported setups (Apache version >= 2.3.3 ). (default:
False)
--redirect Automatically redirect all HTTP traffic to HTTPS for
the newly authenticated vhost. (default: redirect
enabled for install and run, disabled for enhance)
--no-redirect Do not automatically redirect all HTTP traffic to
HTTPS for the newly authenticated vhost. (default:
redirect enabled for install and run, disabled for
enhance)
--hsts Add the Strict-Transport-Security header to every HTTP
response. Forcing browser to always use SSL for the
domain. Defends against SSL Stripping. (default: None)
--uir Add the "Content-Security-Policy: upgrade-insecure-
requests" header to every HTTP response. Forcing the
browser to use https:// for every http:// resource.
(default: None)
--staple-ocsp Enables OCSP Stapling. A valid OCSP response is
stapled to the certificate that the server offers
during TLS. (default: None)
--strict-permissions Require that all configuration files are owned by the
current user; only needed if your config is somewhere
unsafe like /tmp/ (default: False)
--auto-hsts Gradually increasing max-age value for HTTP Strict
Transport Security security header (default: False) testing:
The following flags are meant for testing and integration purposes only.
--test-cert, --staging
Use the staging server to obtain or revoke test
(invalid) certificates; equivalent to --server
https://acme-staging-v02.api.letsencrypt.org/directory
(default: False)
--debug Show tracebacks in case of errors (default: False)
--no-verify-ssl Disable verification of the ACME server's certificate.
The root certificates trusted by Certbot can be
overriden by setting the REQUESTS_CA_BUNDLE
environment variable. (default: False)
--http-01-port HTTP01_PORT
Port used in the http-01 challenge. This only affects
the port Certbot listens on. A conforming ACME server
will still attempt to connect on port 80. (default:
80)
--http-01-address HTTP01_ADDRESS
The address the server listens to during http-01
challenge. (default: )
--https-port HTTPS_PORT
Port used to serve HTTPS. This affects which port
Nginx will listen on after a LE certificate is
installed. (default: 443)
--break-my-certs Be willing to replace or renew valid certificates with
invalid (testing/staging) certificates (default:
False) paths:
Flags for changing execution paths & servers
--cert-path CERT_PATH
Path to where certificate is saved (with certonly
--csr), installed from, or revoked (default: None)
--key-path KEY_PATH Path to private key for certificate installation or
revocation (if account key is missing) (default: None)
--fullchain-path FULLCHAIN_PATH
Accompanying path to a full certificate chain
(certificate plus chain). (default: None)
--chain-path CHAIN_PATH
Accompanying path to a certificate chain. (default:
None)
--config-dir CONFIG_DIR
Configuration directory. (default: /etc/letsencrypt)
--work-dir WORK_DIR Working directory. (default: /var/lib/letsencrypt)
--logs-dir LOGS_DIR Logs directory. (default: /var/log/letsencrypt)
--server SERVER ACME Directory Resource URI. (default:
https://acme-v02.api.letsencrypt.org/directory) manage:
Various subcommands and flags are available for managing your
certificates:
certificates List certificates managed by Certbot
delete Clean up all files related to a certificate
renew Renew all certificates (or one specified with --cert-
name)
revoke Revoke a certificate specified with --cert-path or
--cert-name
update_symlinks Recreate symlinks in your /etc/letsencrypt/live/
directory run:
Options for obtaining & installing certificates certonly:
Options for modifying how a certificate is obtained
--csr CSR Path to a Certificate Signing Request (CSR) in DER or
PEM format. Currently --csr only works with the
'certonly' subcommand. (default: None) renew:
The 'renew' subcommand will attempt to renew any certificates previously
obtained if they are close to expiry, and print a summary of the results.
By default, 'renew' will reuse the plugins and options used to obtain or
most recently renew each certificate. You can test whether future renewals
will succeed with `--dry-run`. Individual certificates can be renewed with
the `--cert-name` option. Hooks are available to run commands before and
after renewal; see https://certbot.eff.org/docs/using.html#renewal for
more information on these.
--pre-hook PRE_HOOK Command to be run in a shell before obtaining any
certificates. Intended primarily for renewal, where it
can be used to temporarily shut down a webserver that
might conflict with the standalone plugin. This will
only be called if a certificate is actually to be
obtained/renewed. When renewing several certificates
that have identical pre-hooks, only the first will be
executed. (default: None)
--post-hook POST_HOOK
Command to be run in a shell after attempting to
obtain/renew certificates. Can be used to deploy
renewed certificates, or to restart any servers that
were stopped by --pre-hook. This is only run if an
attempt was made to obtain/renew a certificate. If
multiple renewed certificates have identical post-
hooks, only one will be run. (default: None)
--deploy-hook DEPLOY_HOOK
Command to be run in a shell once for each
successfully issued certificate. For this command, the
shell variable $RENEWED_LINEAGE will point to the
config live subdirectory (for example,
"/etc/letsencrypt/live/example.com") containing the
new certificates and keys; the shell variable
$RENEWED_DOMAINS will contain a space-delimited list
of renewed certificate domains (for example,
"example.com www.example.com") (default: None)
--disable-hook-validation
Ordinarily the commands specified for --pre-
hook/--post-hook/--deploy-hook will be checked for
validity, to see if the programs being run are in the
$PATH, so that mistakes can be caught early, even when
the hooks aren't being run just yet. The validation is
rather simplistic and fails if you use more advanced
shell constructs, so you can use this switch to
disable it. (default: False)
--no-directory-hooks Disable running executables found in Certbot's hook
directories during renewal. (default: False)
--disable-renew-updates
Disable automatic updates to your server configuration
that would otherwise be done by the selected installer
plugin, and triggered when the user executes "certbot
renew", regardless of if the certificate is renewed.
This setting does not apply to important TLS
configuration updates. (default: False)
--no-autorenew Disable auto renewal of certificates. (default: False) certificates:
List certificates managed by Certbot delete:
Options for deleting a certificate revoke:
Options for revocation of certificates
--reason {unspecified,keycompromise,affiliationchanged,superseded,cessationofoperation}
Specify reason for revoking certificate. (default:
unspecified)
--delete-after-revoke
Delete certificates after revoking them, along with
all previous and later versions of those certificates.
(default: None)
--no-delete-after-revoke
Do not delete certificates after revoking them. This
option should be used with caution because the 'renew'
subcommand will attempt to renew undeleted revoked
certificates. (default: None) register:
Options for account registration
--register-unsafely-without-email
Specifying this flag enables registering an account
with no email address. This is strongly discouraged,
because you will be unable to receive notice about
impending expiration or revocation of your
certificates or problems with your Certbot
installation that will lead to failure to renew.
(default: False)
-m EMAIL, --email EMAIL
Email used for registration and recovery contact. Use
comma to register multiple emails, ex:
u1@example.com,u2@example.com. (default: Ask).
--eff-email Share your e-mail address with EFF (default: None)
--no-eff-email Don't share your e-mail address with EFF (default:
None) update_account:
Options for account modification unregister:
Options for account deactivation.
--account ACCOUNT_ID Account ID to use (default: None) install:
Options for modifying how a certificate is deployed rollback:
Options for rolling back server configuration changes
--checkpoints N Revert configuration N number of checkpoints.
(default: 1) plugins:
Options for the "plugins" subcommand
--init Initialize plugins. (default: False)
--prepare Initialize and prepare plugins. (default: False)
--authenticators Limit to authenticator plugins only. (default: None)
--installers Limit to installer plugins only. (default: None) update_symlinks:
Recreates certificate and key symlinks in /etc/letsencrypt/live, if you
changed them by hand or edited a renewal configuration file enhance:
Helps to harden the TLS configuration by adding security enhancements to
already existing configuration. show_account:
Options useful for the "show_account" subcommand: plugins:
Plugin Selection: Certbot client supports an extensible plugins
architecture. See 'certbot plugins' for a list of all installed plugins
and their names. You can force a particular plugin by setting options
provided below. Running --help <plugin_name> will list flags specific to
that plugin.
--configurator CONFIGURATOR
Name of the plugin that is both an authenticator and
an installer. Should not be used together with
--authenticator or --installer. (default: Ask)
-a AUTHENTICATOR, --authenticator AUTHENTICATOR
Authenticator plugin name. (default: None)
-i INSTALLER, --installer INSTALLER
Installer plugin name (also used to find domains).
(default: None)
--apache Obtain and install certificates using Apache (default:
False)
--nginx Obtain and install certificates using Nginx (default:
False)
--standalone Obtain certificates using a "standalone" webserver.
(default: False)
--manual Provide laborious manual instructions for obtaining a
certificate (default: False)
--webroot Obtain certificates by placing files in a webroot
directory. (default: False)
--dns-cloudflare Obtain certificates using a DNS TXT record (if you are
using Cloudflare for DNS). (default: False)
--dns-digitalocean Obtain certificates using a DNS TXT record (if you are
using DigitalOcean for DNS). (default: False)
--dns-dnsimple Obtain certificates using a DNS TXT record (if you are
using DNSimple for DNS). (default: False)
--dns-dnsmadeeasy Obtain certificates using a DNS TXT record (if you are
using DNS Made Easy for DNS). (default: False)
--dns-gehirn Obtain certificates using a DNS TXT record (if you are
using Gehirn Infrastructure Service for DNS).
(default: False)
--dns-google Obtain certificates using a DNS TXT record (if you are
using Google Cloud DNS). (default: False)
--dns-linode Obtain certificates using a DNS TXT record (if you are
using Linode for DNS). (default: False)
--dns-luadns Obtain certificates using a DNS TXT record (if you are
using LuaDNS for DNS). (default: False)
--dns-nsone Obtain certificates using a DNS TXT record (if you are
using NS1 for DNS). (default: False)
--dns-ovh Obtain certificates using a DNS TXT record (if you are
using OVH for DNS). (default: False)
--dns-rfc2136 Obtain certificates using a DNS TXT record (if you are
using BIND for DNS). (default: False)
--dns-route53 Obtain certificates using a DNS TXT record (if you are
using Route53 for DNS). (default: False)
--dns-sakuracloud Obtain certificates using a DNS TXT record (if you are
using Sakura Cloud for DNS). (default: False) apache:
Apache Web Server plugin (Please note that the default values of the
Apache plugin options change depending on the operating system Certbot is
run on.)
--apache-enmod APACHE_ENMOD
Path to the Apache 'a2enmod' binary (default: None)
--apache-dismod APACHE_DISMOD
Path to the Apache 'a2dismod' binary (default: None)
--apache-le-vhost-ext APACHE_LE_VHOST_EXT
SSL vhost configuration extension (default: -le-
ssl.conf)
--apache-server-root APACHE_SERVER_ROOT
Apache server root directory (default: /etc/apache2)
--apache-vhost-root APACHE_VHOST_ROOT
Apache server VirtualHost configuration root (default:
None)
--apache-logs-root APACHE_LOGS_ROOT
Apache server logs directory (default:
/var/log/apache2)
--apache-challenge-location APACHE_CHALLENGE_LOCATION
Directory path for challenge configuration (default:
/etc/apache2)
--apache-handle-modules APACHE_HANDLE_MODULES
Let installer handle enabling required modules for you
(Only Ubuntu/Debian currently) (default: False)
--apache-handle-sites APACHE_HANDLE_SITES
Let installer handle enabling sites for you (Only
Ubuntu/Debian currently) (default: False)
--apache-ctl APACHE_CTL
Full path to Apache control script (default:
apache2ctl)
--apache-bin APACHE_BIN
Full path to apache2/httpd binary (default: None) dns-cloudflare:
Obtain certificates using a DNS TXT record (if you are using Cloudflare
for DNS).
--dns-cloudflare-propagation-seconds DNS_CLOUDFLARE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10)
--dns-cloudflare-credentials DNS_CLOUDFLARE_CREDENTIALS
Cloudflare credentials INI file. (default: None) dns-digitalocean:
Obtain certificates using a DNS TXT record (if you are using DigitalOcean
for DNS).
--dns-digitalocean-propagation-seconds DNS_DIGITALOCEAN_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10)
--dns-digitalocean-credentials DNS_DIGITALOCEAN_CREDENTIALS
DigitalOcean credentials INI file. (default: None) dns-dnsimple:
Obtain certificates using a DNS TXT record (if you are using DNSimple for
DNS).
--dns-dnsimple-propagation-seconds DNS_DNSIMPLE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-dnsimple-credentials DNS_DNSIMPLE_CREDENTIALS
DNSimple credentials INI file. (default: None) dns-dnsmadeeasy:
Obtain certificates using a DNS TXT record (if you are using DNS Made Easy
for DNS).
--dns-dnsmadeeasy-propagation-seconds DNS_DNSMADEEASY_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-dnsmadeeasy-credentials DNS_DNSMADEEASY_CREDENTIALS
DNS Made Easy credentials INI file. (default: None) dns-gehirn:
Obtain certificates using a DNS TXT record (if you are using Gehirn
Infrastructure Service for DNS).
--dns-gehirn-propagation-seconds DNS_GEHIRN_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-gehirn-credentials DNS_GEHIRN_CREDENTIALS
Gehirn Infrastructure Service credentials file.
(default: None) dns-google:
Obtain certificates using a DNS TXT record (if you are using Google Cloud
DNS for DNS).
--dns-google-propagation-seconds DNS_GOOGLE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-google-credentials DNS_GOOGLE_CREDENTIALS
Path to Google Cloud DNS service account JSON file.
(See https://developers.google.com/identity/protocols/
OAuth2ServiceAccount#creatinganaccount forinformation
about creating a service account and
https://cloud.google.com/dns/access-
control#permissions_and_roles for information about
therequired permissions.) (default: None) dns-linode:
Obtain certificates using a DNS TXT record (if you are using Linode for
DNS).
--dns-linode-propagation-seconds DNS_LINODE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 120)
--dns-linode-credentials DNS_LINODE_CREDENTIALS
Linode credentials INI file. (default: None) dns-luadns:
Obtain certificates using a DNS TXT record (if you are using LuaDNS for
DNS).
--dns-luadns-propagation-seconds DNS_LUADNS_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-luadns-credentials DNS_LUADNS_CREDENTIALS
LuaDNS credentials INI file. (default: None) dns-nsone:
Obtain certificates using a DNS TXT record (if you are using NS1 for DNS).
--dns-nsone-propagation-seconds DNS_NSONE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-nsone-credentials DNS_NSONE_CREDENTIALS
NS1 credentials file. (default: None) dns-ovh:
Obtain certificates using a DNS TXT record (if you are using OVH for DNS).
--dns-ovh-propagation-seconds DNS_OVH_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 120)
--dns-ovh-credentials DNS_OVH_CREDENTIALS
OVH credentials INI file. (default: None) dns-rfc2136:
Obtain certificates using a DNS TXT record (if you are using BIND for
DNS).
--dns-rfc2136-propagation-seconds DNS_RFC2136_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-rfc2136-credentials DNS_RFC2136_CREDENTIALS
RFC 2136 credentials INI file. (default: None) dns-route53:
Obtain certificates using a DNS TXT record (if you are using AWS Route53
for DNS).
--dns-route53-propagation-seconds DNS_ROUTE53_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10) dns-sakuracloud:
Obtain certificates using a DNS TXT record (if you are using Sakura Cloud
for DNS).
--dns-sakuracloud-propagation-seconds DNS_SAKURACLOUD_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 90)
--dns-sakuracloud-credentials DNS_SAKURACLOUD_CREDENTIALS
Sakura Cloud credentials file. (default: None) manual:
Authenticate through manual configuration or custom shell scripts. When
using shell scripts, an authenticator script must be provided. The
environment variables available to this script depend on the type of
challenge. $CERTBOT_DOMAIN will always contain the domain being
authenticated. For HTTP-01 and DNS-01, $CERTBOT_VALIDATION is the
validation string, and $CERTBOT_TOKEN is the filename of the resource
requested when performing an HTTP-01 challenge. An additional cleanup
script can also be provided and can use the additional variable
$CERTBOT_AUTH_OUTPUT which contains the stdout output from the auth
script. For both authenticator and cleanup script, on HTTP-01 and DNS-01
challenges, $CERTBOT_REMAINING_CHALLENGES will be equal to the number of
challenges that remain after the current one, and $CERTBOT_ALL_DOMAINS
contains a comma-separated list of all domains that are challenged for the
current certificate.
--manual-auth-hook MANUAL_AUTH_HOOK
Path or command to execute for the authentication
script (default: None)
--manual-cleanup-hook MANUAL_CLEANUP_HOOK
Path or command to execute for the cleanup script
(default: None) nginx:
Nginx Web Server plugin
--nginx-server-root NGINX_SERVER_ROOT
Nginx server root directory. (default: /etc/nginx or
/usr/local/etc/nginx)
--nginx-ctl NGINX_CTL
Path to the 'nginx' binary, used for 'configtest' and
retrieving nginx version number. (default: nginx)
--nginx-sleep-seconds NGINX_SLEEP_SECONDS
Number of seconds to wait for nginx configuration
changes to apply when reloading. (default: 1) null:
Null Installer standalone:
Spin up a temporary webserver webroot:
Place files in webroot directory
--webroot-path WEBROOT_PATH, -w WEBROOT_PATH
public_html / webroot path. This can be specified
multiple times to handle different domains; each
domain will have the webroot path that preceded it.
For instance: `-w /var/www/example -d example.com -d
www.example.com -w /var/www/thing -d thing.net -d
m.thing.net` (default: Ask)
--webroot-map WEBROOT_MAP
JSON dictionary mapping domains to webroot paths; this
implies -d for each entry. You may need to escape this
from your shell. E.g.: --webroot-map
'{"eg1.is,m.eg1.is":"/www/eg1/", "eg2.is":"/www/eg2"}'
This option is merged with, but takes precedence over,
-w / -d entries. At present, if you put webroot-map in
a config file, it needs to be on a single line, like:
webroot-map = {"example.com":"/var/www"}. (default:
{})
If you're having problems, we recommend posting on the Let's Encrypt Community Forum.
If you find a bug in the software, please do report it in our issue tracker. Remember to give us as much information as possible:
Certbot has the same system requirements when set up for development. While the section below will help you install Certbot and its dependencies, Certbot needs to be run on a UNIX-like OS so if you're using Windows, you'll need to set up a (virtual) machine running an OS such as Linux and continue with these instructions on that UNIX-like OS.
Running the client in developer mode from your local tree is a little different than running Certbot as a user. To get set up, clone our git repository by running:
git clone https://github.com/certbot/certbot
If you're running on a UNIX-like OS, you can run the following commands to install dependencies and set up a virtual environment where you can run Certbot.
Install and configure the OS system dependencies required to run Certbot.
# For APT-based distributions (e.g. Debian, Ubuntu ...) sudo apt update sudo apt install python3-dev python3-venv gcc libaugeas0 libssl-dev \
libffi-dev ca-certificates openssl # For RPM-based distributions (e.g. Fedora, CentOS ...) # NB1: old distributions will use yum instead of dnf # NB2: RHEL-based distributions use python3X-devel instead of python3-devel (e.g. python36-devel) sudo dnf install python3-devel gcc augeas-libs openssl-devel libffi-devel \
redhat-rpm-config ca-certificates openssl # For macOS installations with Homebrew already installed and configured # NB: If you also run `brew install python` you don't need the ~/lib # directory created below, however, Certbot's Apache plugin won't work # if you use Python installed from other sources such as pyenv or the # version provided by Apple. brew install augeas mkdir ~/lib ln -s $(brew --prefix)/lib/libaugeas* ~/lib
Set up the Python virtual environment that will host your Certbot local instance.
cd certbot python tools/venv.py
NOTE:
You can now run the copy of Certbot from git either by executing venv/bin/certbot, or by activating the virtual environment. You can do the latter by running:
source venv/bin/activate
After running this command, certbot and development tools like ipdb3, ipython, pytest, and tox are available in the shell where you ran the command. These tools are installed in the virtual environment and are kept separate from your global Python installation. This works by setting environment variables so the right executables are found and Python can pull in the versions of various packages needed by Certbot. More information can be found in the virtualenv docs.
You can find the open issues in the github issue tracker. Comparatively easy ones are marked good first issue. If you're starting work on something, post a comment to let others know and seek feedback on your plan where appropriate.
Once you've got a working branch, you can open a pull request. All changes in your pull request must have thorough unit test coverage, pass our tests, and be compliant with the coding style.
You can test your code in several ways:
NOTE:
When you are working in a file foo.py, there should also be a file foo_test.py either in the same directory as foo.py or in the tests subdirectory (if there isn't, make one). While you are working on your code and tests, run python foo_test.py to run the relevant tests.
For debugging, we recommend putting import ipdb; ipdb.set_trace() statements inside the source code.
Once you are done with your code changes, and the tests in foo_test.py pass, run all of the unit tests for Certbot and check for coverage with tox -e py3-cover. You should then check for code style with tox -e lint (all files) or pylint --rcfile=.pylintrc path/to/file.py (single file at a time).
Once all of the above is successful, you may run the full test suite using tox --skip-missing-interpreters. We recommend running the commands above first, because running all tests like this is very slow, and the large amount of output can make it hard to find specific failures when they happen.
WARNING:
Generally it is sufficient to open a pull request and let Github and Azure Pipelines run integration tests for you. However, you may want to run them locally before submitting your pull request. You need Docker and docker-compose installed and working.
The tox environment integration will setup Pebble, the Let's Encrypt ACME CA server for integration testing, then launch the Certbot integration tests.
With a user allowed to access your local Docker daemon, run:
tox -e integration
Tests will be run using pytest. A test report and a code coverage report will be displayed at the end of the integration tests execution.
You can also manually execute Certbot against a local instance of the Pebble ACME server. This is useful to verify that the modifications done to the code makes Certbot behave as expected.
To do so you need:
The virtual environment set up with python tools/venv.py contains two CLI tools that can be used once the virtual environment is activated:
run_acme_server
NOTE:
certbot_test [ARGS...]
Here is a typical workflow to verify that Certbot successfully issued a certificate using an HTTP-01 challenge on a machine with Python 3:
python tools/venv.py source venv/bin/activate run_acme_server & certbot_test certonly --standalone -d test.example.com # To stop Pebble, launch `fg` to get back the background job, then press CTRL+C
Certbot uses Azure Pipelines to run continuous integration tests. If you are using our Azure setup, a branch whose name starts with test- will run all tests on that branch.
The following components of the Certbot repository are distributed to users:
Certbot has a plugin architecture to facilitate support for different webservers, other TLS servers, and operating systems. The interfaces available for plugins to implement are defined in interfaces.py and plugins/common.py.
The main two plugin interfaces are Authenticator, which implements various ways of proving domain control to a certificate authority, and Installer, which configures a server to use a certificate once it is issued. Some plugins, like the built-in Apache and Nginx plugins, implement both interfaces and perform both tasks. Others, like the built-in Standalone authenticator, implement just one interface.
Authenticators are plugins that prove control of a domain name by solving a challenge provided by the ACME server. ACME currently defines several types of challenges: HTTP, TLS-ALPN, and DNS, represented by classes in acme.challenges. An authenticator plugin should implement support for at least one challenge type.
An Authenticator indicates which challenges it supports by implementing get_chall_pref(domain) to return a sorted list of challenge types in preference order.
An Authenticator must also implement perform(achalls), which "performs" a list of challenges by, for instance, provisioning a file on an HTTP server, or setting a TXT record in DNS. Once all challenges have succeeded or failed, Certbot will call the plugin's cleanup(achalls) method to remove any files or DNS records that were needed only during authentication.
Installers plugins exist to actually setup the certificate in a server, possibly tweak the security configuration to make it more correct and secure (Fix some mixed content problems, turn on HSTS, redirect to HTTPS, etc). Installer plugins tell the main client about their abilities to do the latter via the supported_enhancements() call. We currently have two Installers in the tree, the ApacheConfigurator. and the NginxConfigurator. External projects have made some progress toward support for IIS, Icecast and Plesk.
Installers and Authenticators will oftentimes be the same class/object (because for instance both tasks can be performed by a webserver like nginx) though this is not always the case (the standalone plugin is an authenticator that listens on port 80, but it cannot install certificates; a postfix plugin would be an installer but not an authenticator).
Installers and Authenticators are kept separate because it should be possible to use the StandaloneAuthenticator (it sets up its own Python server to perform challenges) with a program that cannot solve challenges itself (Such as MTA installers).
There are a few existing classes that may be beneficial while developing a new Installer. Installers aimed to reconfigure UNIX servers may use Augeas for configuration parsing and can inherit from AugeasConfigurator class to handle much of the interface. Installers that are unable to use Augeas may still find the Reverter class helpful in handling configuration checkpoints and rollback.
NOTE:
In the meantime, you're welcome to release it as a third-party plugin. See certbot-dns-ispconfig for one example of that.
Certbot client supports dynamic discovery of plugins through the setuptools entry points using the certbot.plugins group. This way you can, for example, create a custom implementation of Authenticator or the Installer without having to merge it with the core upstream source code. An example is provided in examples/plugins/ directory.
While developing, you can install your plugin into a Certbot development virtualenv like this:
. venv/bin/activate pip install -e examples/plugins/ certbot_test plugins
Your plugin should show up in the output of the last command. If not, it was not installed properly.
Once you've finished your plugin and published it, you can have your users install it system-wide with pip install. Note that this will only work for users who have Certbot installed from OS packages or via pip.
If you'd like your plugin to be used alongside the Certbot snap, you will also have to publish your plugin as a snap. Plugin snaps are regular confined snaps, but normally do not provide any "apps" themselves. Plugin snaps export loadable Python modules to the Certbot snap.
When the Certbot snap runs, it will use its version of Python and prefer Python modules contained in its own snap over modules contained in external snaps. This means that your snap doesn't have to contain things like an extra copy of Python, Certbot, or their dependencies, but also that if you need a different version of a dependency than is already installed in the Certbot snap, the Certbot snap will have to be updated.
Certbot plugin snaps expose their Python modules to the Certbot snap via a snap content interface where certbot-1 is the value for the content attribute. The Certbot snap only uses this to find the names of connected plugin snaps and it expects to find the Python modules to be loaded under lib/python3.8/site-packages/ in the plugin snap. This location is the default when using the core20 base snap and the python snapcraft plugin.
The Certbot snap also provides a separate content interface which you can use to get metadata about the Certbot snap using the content identifier metadata-1.
The script used to generate the snapcraft.yaml files for our own externally snapped plugins can be found at https://github.com/certbot/certbot/blob/master/tools/snap/generate_dnsplugins_snapcraft.sh.
For more information on building externally snapped plugins, see the section on Building the Certbot and DNS plugin snaps.
Once you have created your own snap, if you have the snap file locally, it can be installed for use with Certbot by running:
snap install --classic certbot snap set certbot trust-plugin-with-root=ok snap install --dangerous your-snap-filename.snap sudo snap connect certbot:plugin your-snap-name sudo /snap/bin/certbot plugins
If everything worked, the last command should list your plugin in the list of plugins found by Certbot. Once your snap is published to the snap store, it will be installable through the name of the snap on the snap store without the --dangerous flag. If you are also using Certbot's metadata interface, you can run sudo snap connect your-snap-name:your-plug-name-for-metadata certbot:certbot-metadata to connect your snap to it.
Please:
def foo(arg):
"""Short description.
:param int arg: Some number.
:returns: Argument
:rtype: int
"""
return arg
Python's standard library os module lacks full support for several Windows security features about file permissions (eg. DACLs). However several files handled by Certbot (eg. private keys) need strongly restricted access on both Linux and Windows.
To help with this, the certbot.compat.os module wraps the standard os module, and forbids usage of methods that lack support for these Windows security features.
As a developer, when working on Certbot or its plugins, you must use certbot.compat.os in every place you would need os (eg. from certbot.compat import os instead of import os). Otherwise the tests will fail when your PR is submitted.
Certbot uses the mypy static type checker. Python 3 natively supports official type annotations, which can then be tested for consistency using mypy. Mypy does some type checks even without type annotations; we can find bugs in Certbot even without a fully annotated codebase.
Zulip wrote a great guide to using mypy. It’s useful, but you don’t have to read the whole thing to start contributing to Certbot.
To run mypy on Certbot, use tox -e mypy on a machine that has Python 3 installed.
Also note that OpenSSL, which we rely on, has type definitions for crypto but not SSL. We use both. Those imports should look like this:
from OpenSSL import crypto from OpenSSL import SSL
Steps:
If you have any questions while working on a Certbot issue, don't hesitate to ask for help! You can do this in the Certbot channel in EFF's Mattermost instance for its open source projects as described below.
You can get involved with several of EFF's software projects such as Certbot at the EFF Open Source Contributor Chat Platform. By signing up for the EFF Open Source Contributor Chat Platform, you consent to share your personal information with the Electronic Frontier Foundation, which is the operator and data controller for this platform. The channels will be available both to EFF, and to other users of EFFOSCCP, who may use or disclose information in these channels outside of EFFOSCCP. EFF will use your information, according to the Privacy Policy, to further the mission of EFF, including hosting and moderating the discussions on this platform.
Use of EFFOSCCP is subject to the EFF Code of Conduct. When investigating an alleged Code of Conduct violation, EFF may review discussion channels or direct messages.
Instructions for how to manually build and run the Certbot snap and the externally snapped DNS plugins that the Certbot project supplies are located in the README file at https://github.com/certbot/certbot/tree/master/tools/snap.
Many of the packages in the Certbot repository have documentation in a docs/ directory. This directory is located under the top level directory for the package. For instance, Certbot's documentation is under certbot/docs.
To build the documentation of a package, make sure you have followed the instructions to set up a local copy of Certbot including activating the virtual environment. After that, cd to the docs directory you want to build and run the command:
make clean html
This would generate the HTML documentation in _build/html in your current docs/ directory.
We attempt to pin all of Certbot's dependencies whenever we can for reliability and consistency. Some of the places we have Certbot's dependencies pinned include our snaps, Docker images, Windows installer, CI, and our development environments.
In most cases, the file where dependency versions are specified is tools/requirements.txt. There are two exceptions to this. The first is our "oldest" tests where tools/oldest_constraints.txt is used instead. The purpose of the "oldest" tests is to ensure Certbot continues to work with the oldest versions of our dependencies which we claim to support. The oldest versions of the dependencies we support should also be declared in our setup.py files to communicate this information to our users.
The second exception to using tools/requirements.txt is in our unpinned tests. As of writing this, there is one test we run nightly in CI where we leave Certbot's dependencies unpinned. The thinking behind this test is to help us learn about breaking changes in our dependencies so that we can respond accordingly.
The choices of whether Certbot's dependencies are pinned and what file is used if they are should be automatically handled for you most of the time by Certbot's tooling. The way it works though is tools/pip_install.py (which many of our other tools build on) checks for the presence of environment variables. If CERTBOT_NO_PIN is set to 1, Certbot's dependencies will not be pinned. If that variable is not set and CERTBOT_OLDEST is set to 1, tools/oldest_constraints.txt will be used as constraints for pip. Otherwise, tools/requirements.txt is used as constraints.
tools/requirements.txt and tools/oldest_constraints.txt can be updated using tools/pinning/current/repin.sh and tools/pinning/oldest/repin.sh respectively. This works by using poetry to generate pinnings based on a Poetry project defined by the pyproject.toml file in the same directory as the script. In many cases, you can just run the script to generate updated dependencies, however, if you need to pin back packages or unpin packages that were previously restricted to an older version, you will need to modify the pyproject.toml file. The syntax used by this file is described at https://python-poetry.org/docs/pyproject/ and how dependencies are specified in this file is further described at https://python-poetry.org/docs/dependency-specification/.
If you want to learn more about the design used here, see tools/pinning/DESIGN.md in the Certbot repo.
You can use Docker Compose to quickly set up an environment for running and testing Certbot. To install Docker Compose, follow the instructions at https://docs.docker.com/compose/install/.
NOTE:
Now you can develop on your host machine, but run Certbot and test your changes in Docker. When using docker-compose make sure you are inside your clone of the Certbot repository. As an example, you can run the following command to check for linting errors:
docker-compose run --rm --service-ports development bash -c 'tox -e lint'
You can also leave a terminal open running a shell in the Docker container and modify Certbot code in another window. The Certbot repo on your host machine is mounted inside of the container so any changes you make immediately take effect. To do this, run:
docker-compose run --rm --service-ports development bash
Now running the check for linting errors described above is as easy as:
tox -e lint
We release packages and upload them to PyPI (wheels and source tarballs).
The following scripts are used in the process:
We use git tags to identify releases, using Semantic Versioning. For example: v0.11.1.
Since version 1.21.0, our packages are cryptographically signed by one of four PGP keys:
These keys can be found on major key servers and at https://dl.eff.org/certbot.pub.
Releases before 1.21.0 were signed by the PGP key A2CFB51FA275A7286234E7B24D17C995CD9775F2 which can still be found on major key servers.
All Certbot components including acme, Certbot, and non-third party plugins follow Semantic Versioning both for its Python API and for the application itself. This means that we will not change behavior in a backwards incompatible way except in a new major version of the project.
NOTE:
For Certbot as an application, the command line interface and non-interactive behavior can be considered stable with two exceptions. The first is that no aspects of Certbot's console or log output should be considered stable and it may change at any time. The second is that Certbot's behavior should only be considered stable with certain files but not all. Files with which users should expect Certbot to maintain its current behavior with are:
Certbot's behavior with other files may change at any point.
Another area where Certbot should not be considered stable is its behavior when not run in non-interactive mode which also may change at any point.
In general, if we're making a change that we expect will break some users, we will bump the major version and will have warned about it in a prior release when possible. For our Python API, we will issue warnings using Python's warning module. For application level changes, we will print and log warning messages.
Documentation: https://certbot.eff.org/docs
Software project: https://github.com/certbot/certbot
Notes for developers: https://certbot.eff.org/docs/contributing.html
Main Website: https://certbot.eff.org
Let's Encrypt Website: https://letsencrypt.org
Community: https://community.letsencrypt.org
ACME spec: RFC 8555
ACME working area in github (archived): https://github.com/ietf-wg-acme/acme
Certbot client.
Compatibility layer to run certbot both on Linux and Windows.
This package contains all logic that needs to be implemented specifically for Linux and for Windows. Then the rest of certbot code relies on this module to be platform agnostic.
Compat module to handle files security on Windows and Linux
The definition of the Windows DACL that correspond to a POSIX mode, in the context of Certbot, is explained at https://github.com/certbot/certbot/issues/6356 and is implemented by the method _generate_windows_flags().
This compat module handles various platform specific calls that do not fall into one particular category.
This function returns the exit code, and does not log the result and output of the command.
This compat modules is a wrapper of the core os module that forbids usage of specific operations (e.g. chown, chmod, getuid) that would be harmful to the Windows file security model of Certbot. This module is intended to replace standard os module throughout certbot projects (except acme).
This module has the same API as the os module in the Python standard library except for the functions defined below.
isort:skip_file
Certbot display utilities.
Contains UI methods for LE user operations.
Certbot display.
This module (certbot.display.util) or its companion certbot.display.ops should be used whenever:
Other messages can use the logging module. See log.py.
Yes and No label must begin with different letters, and must contain at least one letter each.
Certbot plugins.
Plugin common functions.
Generic plugin.
See inject_parser_options for docs.
Shown to the user if one or more of the attempted challenges were not a success.
Should describe, in simple language, what the authenticator tried to do, what went wrong and what the user should try as their "next steps".
TODO: auth_hint belongs in Authenticator but can't be added until the next major version of Certbot. For now, it lives in .Plugin and auth_handler will only call it on authenticators that subclass .Plugin. For now, inherit from Plugin to implement and/or override the method.
An installer base class with reverter and ssl_dhparam methods defined.
Installer plugins do not have to inherit from this class.
Reverts all modified files that have not been saved as a checkpoint
A plugin that extends certbot.plugins.common.Installer and implements certbot.interfaces.Authenticator
Represents an virtual host address.
Abstract base for challenge performers.
Common code for DNS Authenticator Plugins.
Base class for DNS Authenticators
Finish up any additional initialization.
Should describe the steps taken and any relevant info to help the user decide which plugin to use.
This method should be able to revert all changes made by perform, even if perform exited abnormally.
Represents a user-supplied filed which stores API credentials.
One of these will probably be the domain name known to the DNS provider.
>>> base_domain_name_guesses('foo.bar.baz.example.com')
['foo.bar.baz.example.com', 'bar.baz.example.com', 'baz.example.com', 'example.com', 'com']
Common code for DNS Authenticator Plugins built on Lexicon.
Encapsulates all communication with a DNS provider via Lexicon.
Base test class for DNS authenticators.
A base test class to reduce duplication between test code for DNS Authenticator Plugins.
Base test class for DNS authenticators built on Lexicon.
New interface style Certbot enhancements
List of expected options parameters: - redirect: None - ensure-http-header: name of header (i.e. Strict-Transport-Security) - ocsp-stapling: certificate chain file path
Enhancement interface that installer plugins can implement in order to provide functionality that configures the software to have a 'Strict-Transport-Security' with initially low max-age value that will increase over time.
The plugins implementing new style enhancements are responsible of handling the saving of configuration checkpoints as well as calling possible restarts of managed software themselves. For update_autohsts method, the installer may have to call prepare() to finalize the plugin initialization.
update_autohsts is called every time when Certbot is run using 'renew' verb. The max-age value should be increased over time using this method.
deploy_autohsts is called for every lineage that has had its certificate renewed. A long HSTS max-age value should be set here, as we should be confident that the user is able to automatically renew their certificates.
NOTE:
Plugin storage class.
Class implementing storage functionality for plugins
Plugin utilities.
Mitigates https://github.com/certbot/certbot/issues/1833
Utilities for running Certbot tests
ACME utilities for testing.
Test utilities.
Dummy installer plugin for test purpose.
Both title and temporary are needed because a save may be intended to be permanent, but the save is not ready to be a full checkpoint.
It is assumed that at most one checkpoint is finalized by this method. Additionally, if an exception is raised, it is assumed a new checkpoint was not finalized.
Finish up any additional initialization.
Should describe the steps taken and any relevant info to help the user decide which plugin to use.
This creates the archive, live, and renewal directories if necessary and creates a simple lineage.
The mock display utility works like a regular mock object, except it also also asserts that methods are called with valid arguments.
The mock created by this patch mocks out Certbot internals. That is, the mock object will be called by the certbot.display.util functions and the mock returned by that call will be used as the display utility. This was done to simplify the transition from zope.component and mocking certbot.display.util functions directly in test code should be preferred over using this function in the future.
See https://github.com/certbot/certbot/issues/8948
The mock display utility works like a regular mock object, except it also asserts that methods are called with valid arguments.
The mock created by this patch mocks out Certbot internals. That is, the mock object will be called by the certbot.display.util functions and the mock returned by that call will be used as the display utility. This was done to simplify the transition from zope.component and mocking certbot.display.util functions directly in test code should be preferred over using this function in the future.
See https://github.com/certbot/certbot/issues/8948
The message argument passed to the display utility methods is passed to stdout's write method.
Mock object with the ability to freeze attributes.
This class works like a regular mock.MagicMock object, except attributes and behavior set before the object is frozen cannot be changed during tests.
If a func argument is provided to the constructor, this function is called first when an instance of FreezableMock is called, followed by the usual behavior defined by MagicMock. The return value of func is ignored.
Base test class which sets up and tears down a temporary directory
Test class which sets up a NamespaceConfig object.
Client annotated ACME challenges.
Please use names such as achall to distinguish from variables "of type" acme.challenges.Challenge (denoted by chall) and ChallengeBody (denoted by challb):
from acme import challenges from acme import messages from certbot import achallenges chall = challenges.DNS(token='foo') challb = messages.ChallengeBody(chall=chall) achall = achallenges.DNS(chall=challb, domain='example.com')
Note, that all annotated challenges act as a proxy objects:
achall.token == challb.token
Client annotated challenge.
Wraps around server provided challenge and annotates with data useful for the client.
Client annotated KeyAuthorizationChallenge challenge.
Client annotated "dns" ACME challenge.
Certbot client crypto utility functions.
Inits key and saves it in PEM format on the filesystem.
NOTE:
Check if csr is a valid CSR for the given domains.
NB: In given file, platform specific newlines characters will be converted into their equivalent unicode counterparts before calculating the hash.
Certbot client errors.
Generic Certbot client error.
Generic AccountStorage error.
Account not found error.
Certbot Reverter error.
Subprocess handling error.
Generic CertStorage error.
Failed to find a hook command in the PATH.
A Unix signal was received while in the ErrorHandler context manager.
Multiple lineages matched what should have been a unique result.
File locking error.
Authorization error.
Failed challenges error.
Certbot Plugin error.
Enhancement was already set
A problem with plugin/configurator selection or setup
Certbot No Installation error.
Certbot Misconfiguration error.
Certbot Plugin function not supported error.
Certbot Plugin Storage error.
Standalone plugin bind error.
Configuration sanity error.
A command line argument was missing in noninteractive usage
Certbot client interfaces.
Accounts storage interface.
Certbot plugin.
Objects providing this interface will be called without satisfying any entry point "extras" (extra dependencies) you might have defined for your plugin, e.g (excerpt from setup.py script):
setup(
...
entry_points={
'certbot.plugins': [
'name=example_project.plugin[plugin_deps]',
],
},
extras_require={
'plugin_deps': ['dep1', 'dep2'],
} )
Therefore, make sure such objects are importable and usable without extras. This is necessary, because CLI does the following operations (in order):
Finish up any additional initialization.
Should describe the steps taken and any relevant info to help the user decide which plugin to use.
1. Be nice and prepend all options and destinations with option_namespace and dest_namespace.
2. Inject options (flags) only. Positional arguments are not allowed, as this would break the CLI.
Generic Certbot Authenticator.
Class represents all possible tools processes that have the ability to perform challenges and attain a certificate.
This method should be able to revert all changes made by perform, even if perform exited abnormally.
Generic Certbot Installer Interface.
Represents any server that an X509 certificate can be placed.
It is assumed that save() is the only method that finalizes a checkpoint. This is important to ensure that checkpoints are restored in a consistent manner if requested by the user or in case of an error.
Using certbot.reverter.Reverter to implement checkpoints, rollback, and recovery can dramatically simplify plugin development.
Both title and temporary are needed because a save may be intended to be permanent, but the save is not ready to be a full checkpoint.
It is assumed that at most one checkpoint is finalized by this method. Additionally, if an exception is raised, it is assumed a new checkpoint was not finalized.
Remove all changes (temporary and permanent) that have not been finalized. This is useful to protect against crashes and other execution interruptions.
Interface to a certificate lineage.
The full chain is the certificate file plus the chain file.
Interface for update types not currently specified by Certbot.
This class allows plugins to perform types of updates that Certbot hasn't defined (yet).
To make use of this interface, the installer should implement the interface methods, and interfaces.GenericUpdater.register(InstallerClass) should be called from the installer code.
The plugins implementing this enhancement are responsible of handling the saving of configuration checkpoints as well as other calls to interface methods of interfaces.Installer such as prepare() and restart()
If an installer is a subclass of the class containing this method, this function will always be called when "certbot renew" is run. If the update defined by the installer should be run conditionally, the installer needs to handle checking the conditions itself.
This method is called once for each lineage.
Interface for update types run when a lineage is renewed
This class allows plugins to perform types of updates that need to run at lineage renewal that Certbot hasn't defined (yet).
To make use of this interface, the installer should implement the interface methods, and interfaces.RenewDeployer.register(InstallerClass) should be called from the installer code.
If an installer is a subclass of the class containing this method, this function will always be called when a certificate has been renewed by running "certbot renew". For example if a plugin needs to copy a certificate over, or change configuration based on the new certificate.
This method is called once for each lineage renewed
Certbot main public entry point.
Tools for checking certificate revocation.
This class figures out OCSP checking on this system, and performs it.
Reverter class saves configuration checkpoints and allows for recovery.
Reverter Class - save and revert configuration checkpoints.
This class can be used by the plugins, especially Installers, to undo changes made to the user's system. Modifications to files and commands to do undo actions taken by the plugin should be registered with this class before the action is taken.
Once a change has been registered with this class, there are three states the change can be in. First, the change can be a temporary change. This should be used for changes that will soon be reverted, such as config changes for the purpose of solving a challenge. Changes are added to this state through calls to add_to_temp_checkpoint() and reverted when revert_temporary_config() or recovery_routine() is called.
The second state a change can be in is in progress. These changes are not temporary, however, they also have not been finalized in a checkpoint. A change must become in progress before it can be finalized. Changes are added to this state through calls to add_to_checkpoint() and reverted when recovery_routine() is called.
The last state a change can be in is finalized in a checkpoint. A change is put into this state by first becoming an in progress change and then calling finalize_checkpoint(). Changes in this state can be reverted through calls to rollback_checkpoints().
As a final note, creating new files and registering undo commands are handled specially and use the methods register_file_creation() and register_undo_command() respectively. Both of these methods can be used to create either temporary or in progress changes.
NOTE:
This function should reinstall the users original configuration files for all saves with temporary=True
Call this method before writing to the file to make sure that the file will be cleaned up if the program exits unexpectedly. (Before a save occurs)
WARNING:
Remove all changes (temporary and permanent) that have not been finalized. This is useful to protect against crashes and other execution interruptions.
Timestamps and permanently saves all changes made through the use of add_to_checkpoint() and register_file_creation()
Utilities for all Certbot.
Action to log a warning when an argument is used.
Deprecated arguments are not shown in the help. If they are used on the command line, a warning is shown stating that the argument is deprecated and no other action is taken.
Special care is taken to ensure func is only called when the process that first imports this module exits rather than any child processes.
This code and the returned tuple is based on the now deprecated distutils.version.LooseVersion class from the Python standard library. Two LooseVersion classes and two lists as returned by this function should compare in the same way. See https://github.com/python/cpython/blob/v3.10.0/Lib/distutils/version.py#L205-L347.
Certbot
| April 16, 2023 | 2.1 |