radosgw – rados REST gateway
Synopsis
Description
radosgw is an HTTP REST gateway for the RADOS object store, a part of the Ceph distributed storage system. It is implemented as a FastCGI module using libfcgi, and can be used in conjunction with any FastCGI capable web server.
Options
- -c ceph.conf, --conf=ceph.conf
Use
ceph.conf
configuration file instead of the default/etc/ceph/ceph.conf
to determine monitor addresses during startup.
- -m monaddress[:port]
Connect to specified monitor (instead of looking through
ceph.conf
).
- -i ID, --id ID
Set the ID portion of name for radosgw
- -n TYPE.ID, --name TYPE.ID
Set the rados user name for the gateway (eg. client.radosgw.gateway)
- --cluster NAME
Set the cluster name (default: ceph)
- -d
Run in foreground, log to stderr
- -f
Run in foreground, log to usual location
- --rgw-region=region
The region where radosgw runs
- --rgw-zone=zone
The zone where radosgw runs
Configuration
Earlier RADOS Gateway had to be configured with Apache
and mod_fastcgi
.
Now, mod_proxy_fcgi
module is used instead of mod_fastcgi
.
mod_proxy_fcgi
works differently than a traditional FastCGI module. This
module requires the service of mod_proxy
which provides support for the
FastCGI protocol. So, to be able to handle FastCGI protocol, both mod_proxy
and mod_proxy_fcgi
have to be present in the server. Unlike mod_fastcgi
,
mod_proxy_fcgi
cannot start the application process. Some platforms have
fcgistarter
for that purpose. However, external launching of application
or process management may be available in the FastCGI application framework
in use.
Apache
must be configured in a way that enables mod_proxy_fcgi
to be
used with localhost tcp.
The following steps show the configuration in Ceph’s configuration file i.e,
/etc/ceph/ceph.conf
and the gateway configuration file i.e,
/etc/httpd/conf.d/rgw.conf
(RPM-based distros) or
/etc/apache2/conf-available/rgw.conf
(Debian-based distros) with localhost
tcp:
For distros with Apache 2.2 and early versions of Apache 2.4 that use localhost TCP, append the following contents to
/etc/ceph/ceph.conf
:[client.radosgw.gateway] host = {hostname} keyring = /etc/ceph/ceph.client.radosgw.keyring log_file = /var/log/ceph/client.radosgw.gateway.log rgw_frontends = fastcgi socket_port=9000 socket_host=0.0.0.0 rgw_print_continue = false
Add the following content in the gateway configuration file:
For Debian/Ubuntu add in
/etc/apache2/conf-available/rgw.conf
:<VirtualHost *:80> ServerName localhost DocumentRoot /var/www/html ErrorLog /var/log/apache2/rgw_error.log CustomLog /var/log/apache2/rgw_access.log combined # LogLevel debug RewriteEngine On RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L] SetEnv proxy-nokeepalive 1 ProxyPass / fcgi://localhost:9000/ </VirtualHost>
For CentOS/RHEL add in
/etc/httpd/conf.d/rgw.conf
:<VirtualHost *:80> ServerName localhost DocumentRoot /var/www/html ErrorLog /var/log/httpd/rgw_error.log CustomLog /var/log/httpd/rgw_access.log combined # LogLevel debug RewriteEngine On RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L] SetEnv proxy-nokeepalive 1 ProxyPass / fcgi://localhost:9000/ </VirtualHost>
Add the following content in the gateway configuration file:
For CentOS/RHEL add in
/etc/httpd/conf.d/rgw.conf
:<VirtualHost *:80> ServerName localhost DocumentRoot /var/www/html ErrorLog /var/log/httpd/rgw_error.log CustomLog /var/log/httpd/rgw_access.log combined # LogLevel debug RewriteEngine On RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L] SetEnv proxy-nokeepalive 1 ProxyPass / unix:///var/run/ceph/ceph.radosgw.gateway.fastcgi.sock|fcgi://localhost:9000/ </VirtualHost>
Generate a key for radosgw to use for authentication with the cluster.
ceph-authtool -C -n client.radosgw.gateway --gen-key /etc/ceph/keyring.radosgw.gateway ceph-authtool -n client.radosgw.gateway --cap mon 'allow rw' --cap osd 'allow rwx' /etc/ceph/keyring.radosgw.gateway
Add the key to the auth entries.
ceph auth add client.radosgw.gateway --in-file=keyring.radosgw.gateway
Start Apache and radosgw.
Debian/Ubuntu:
sudo /etc/init.d/apache2 start sudo /etc/init.d/radosgw start
CentOS/RHEL:
sudo apachectl start sudo /etc/init.d/ceph-radosgw start
Usage Logging
radosgw maintains an asynchronous usage log. It accumulates statistics about user operations and flushes it periodically. The logs can be accessed and managed through radosgw-admin.
The information that is being logged contains total data transfer, total operations, and total successful operations. The data is being accounted in an hourly resolution under the bucket owner, unless the operation was done on the service (e.g., when listing a bucket) in which case it is accounted under the operating user.
Following is an example configuration:
[client.radosgw.gateway]
rgw enable usage log = true
rgw usage log tick interval = 30
rgw usage log flush threshold = 1024
rgw usage max shards = 32
rgw usage max user shards = 1
The total number of shards determines how many total objects hold the usage log information. The per-user number of shards specify how many objects hold usage information for a single user. The tick interval configures the number of seconds between log flushes, and the flush threshold specify how many entries can be kept before resorting to synchronous flush.
Availability
radosgw is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at https://docs.ceph.com for more information.
See also
ceph(8) radosgw-admin(8)