| snap(8) | System Manager's Manual | snap(8) |
snap - Tool to interact with snaps
snap [OPTIONS]
The snap command lets you install, configure, refresh and remove snaps. Snaps are packages that work across many different Linux distributions, enabling secure delivery and operation of the latest apps and utilities.
Abort a pending change
The abort command attempts to abort a change that still has pending tasks.
Usage: snap [OPTIONS] abort [abort-OPTIONS]
Add an assertion to the system
The ack command tries to add an assertion to the system assertion database.
The assertion may also be a newer revision of a pre-existing assertion that it will replace.
To succeed the assertion must be valid, its signature verified with a known public key and the assertion consistent with and its prerequisite in the database.
Set up a manual alias
The alias command aliases the given snap application to the given alias.
Once this manual alias is setup the respective application command can be invoked just using the alias.
Usage: snap [OPTIONS] alias [alias-OPTIONS]
List aliases in the system
The aliases command lists all aliases available in the system and their status.
$ snap aliases <snap>
Lists only the aliases defined by the specified snap.
An alias noted as undefined means it was explicitly enabled or disabled but is not defined in the current revision of the snap, possibly temporarily (e.g. because of a revert). This can cleared with 'snap alias --reset'.
List system changes
The changes command displays a summary of system changes performed recently.
Usage: snap [OPTIONS] changes [changes-OPTIONS]
Check a snapshot
The check-snapshot command verifies the user, system and configuration data of the snaps included in the specified snapshot.
The check operation runs the same data integrity verification that is performed when a snapshot is restored.
By default, this command checks all the data in a snapshot. Alternatively, you can specify the data of which snaps to check, or for which users, or a combination of these.
If a snap is included in a check-snapshot operation, excluding its system and configuration data from the check is not currently possible. This restriction may be lifted in the future.
Usage: snap [OPTIONS] check-snapshot [check-snapshot-OPTIONS]
Connect a plug to a slot
The connect command connects a plug to a slot. It may be called in the following ways:
$ snap connect <snap>:<plug> <snap>:<slot>
Connects the provided plug to the given slot.
$ snap connect <snap>:<plug> <snap>
Connects the specific plug to the only slot in the provided snap that matches the connected interface. If more than one potential slot exists, the command fails.
$ snap connect <snap>:<plug>
Connects the provided plug to the slot in the core snap with a name matching the plug name.
Usage: snap [OPTIONS] connect [connect-OPTIONS]
List interface connections
The connections command lists connections between plugs and slots in the system.
Unless <snap> is provided, the listing is for connected plugs and slots for all snaps in the system. In this mode, pass --all to also list unconnected plugs and slots.
$ snap connections <snap>
Lists connected and unconnected plugs and slots for the specified snap.
Usage: snap [OPTIONS] connections [connections-OPTIONS]
Create cohort keys for a set of snaps
The create-cohort command creates a set of cohort keys for a given set of snaps.
A cohort is a view or snapshot of a snap's "channel map" at a given point in time that fixes the set of revisions for the snap given other constraints (e.g. channel or architecture). The cohort is then identified by an opaque per-snap key that works across systems. Installations or refreshes of the snap using a given cohort key would use a fixed revision for up to 90 days, after which a new set of revisions would be fixed under that same cohort key and a new 90 days window started.
Run debug commands
The debug command contains a selection of additional sub-commands.
Debug commands can be removed without notice and may not work on non-development systems.
Print the confinement mode the system operates in
The confinement command will print the confinement mode (strict, partial or none) the system operates in.
Check network connectivity status
The connectivity command checks the network connectivity of snapd.
Migrate snaps' directory to ~/Snap.
Migrate snaps' directory to ~/Snap.
Usage: debug migrate-home [migrate-home-OPTIONS]
Print system paths
The paths command prints the list of paths detected and used by snapd.
Print sandbox features available on the system
The sandbox command prints tags describing features of individual sandbox components used by snapd on a given system.
Usage: debug sandbox-features [sandbox-features-OPTIONS]
Obtain stacktraces of all snapd goroutines
Obtain stacktraces of all snapd goroutines.
Inspect a snapd state file.
Inspect a snapd state file, bypassing snapd API.
Usage: debug state [state-OPTIONS]
Get the timings of the tasks of a change
The timings command displays details about the time each task runs.
Usage: debug timings [timings-OPTIONS]
Disable a snap in the system
The disable command disables a snap. The binaries and services of the snap will no longer be available, but all the data is still available and the snap can easily be enabled again.
Usage: snap [OPTIONS] disable [disable-OPTIONS]
Disconnect a plug from a slot
The disconnect command disconnects a plug from a slot. It may be called in the following ways:
$ snap disconnect <snap>:<plug> <snap>:<slot>
Disconnects the specific plug from the specific slot.
$ snap disconnect <snap>:<slot or plug>
Disconnects everything from the provided plug or slot. The snap name may be omitted for the core snap.
When an automatic connection is manually disconnected, its disconnected state is retained after a snap refresh. The --forget flag can be added to the disconnect command to reset this behaviour, and consequently re-enable an automatic reconnection after a snap refresh.
Usage: snap [OPTIONS] disconnect [disconnect-OPTIONS]
Download the given snap
The download command downloads the given snap and its supporting assertions to the current directory with .snap and .assert file extensions, respectively.
Usage: snap [OPTIONS] download [download-OPTIONS]
Enable a snap in the system
The enable command enables a snap that was previously disabled.
Usage: snap [OPTIONS] enable [enable-OPTIONS]
Export a snapshot
Export a snapshot to the given filename.
Find packages to install
The find command queries the store for available packages.
With the --private flag, which requires the user to be logged-in to the store (see 'snap help login'), it instead searches for private snaps that the user has developer access to, either directly or through the store's collaboration feature.
A green check mark (given color and unicode support) after a publisher name indicates that the publisher has been verified.
Usage: snap [OPTIONS] find [find-OPTIONS]
Delete a snapshot
The forget command deletes a snapshot. This operation can not be undone.
A snapshot contains archives for the user, system and configuration data of each snap included in the snapshot.
By default, this command forgets all the data in a snapshot. Alternatively, you can specify the data of which snaps to forget.
Usage: snap [OPTIONS] forget [forget-OPTIONS]
Print configuration options
The get command prints configuration options for the provided snap.
$ snap get snap-name username
frank
If multiple option names are provided, the corresponding values are returned:
$ snap get snap-name username password
Key Value
username frank
password ...
Nested values may be retrieved via a dotted path:
$ snap get snap-name author.name
frank
Usage: snap [OPTIONS] get [get-OPTIONS]
Show help about a command
The help command displays information about snap commands.
Usage: snap [OPTIONS] help [help-OPTIONS]
Import a snapshot
Import an exported snapshot set to the system. The snapshot is imported with a new snapshot ID and can be restored using the restore command.
Usage: snap [OPTIONS] import-snapshot [import-snapshot-OPTIONS]
Show detailed information about snaps
The info command shows detailed information about snaps.
The snaps can be specified by name or by path; names are looked for both in the store and in the installed snaps; paths can refer to a .snap file, or to a directory that contains an unpacked snap suitable for 'snap try' (an example of this would be the 'prime' directory snapcraft produces).
Usage: snap [OPTIONS] info [info-OPTIONS]
Install snaps on the system
The install command installs the named snaps on the system.
To install multiple instances of the same snap, append an underscore and a unique identifier (for each instance) to a snap's name.
With no further options, the snaps are installed tracking the stable channel, with strict security confinement. All available channels of a snap are listed in its 'snap info' output.
Revision choice via the --revision override requires the user to have developer access to the snap, either directly or through the store's collaboration feature, and to be logged in (see 'snap help login').
Note that a later refresh will typically undo a revision override, taking the snap back to the current revision of the channel it's tracking.
Use --name to set the instance name when installing from snap file.
Usage: snap [OPTIONS] install [install-OPTIONS]
Show details of snap interfaces
The interface command shows details of snap interfaces.
If no interface name is provided, a list of interface names with at least one connection is shown, or a list of all interfaces if --all is provided.
Usage: snap [OPTIONS] interface [interface-OPTIONS]
Show known assertions of the provided type
The known command shows known assertions of the provided type. If header=value pairs are provided after the assertion type, the assertions shown must also have the specified headers matching the provided values.
Usage: snap [OPTIONS] known [known-OPTIONS]
List installed snaps
The list command displays a summary of snaps installed in the current system.
A green check mark (given color and unicode support) after a publisher name indicates that the publisher has been verified.
Usage: snap [OPTIONS] list [list-OPTIONS]
Authenticate to snapd and the store
The login command authenticates the user to snapd and the snap store, and saves credentials into the ~/.snap/auth.json file. Further communication with snapd will then be made using those credentials.
It's not necessary to log in to interact with snapd. Doing so, however, enables interactions without sudo, as well as some some developer-oriented features as detailed in the help for the find, install and refresh commands.
An account can be set up at https://login.ubuntu.com
Log out of snapd and the store
The logout command logs the current user out of snapd and the store.
Retrieve logs for services
The logs command fetches logs of the given services and displays them in chronological order.
Usage: snap [OPTIONS] logs [logs-OPTIONS]
Get the active model for this device
The model command returns the active model assertion information for this device.
By default, only the essential model identification information is included in the output, but this can be expanded to include all of an assertion's non-meta headers.
The verbose output is presented in a structured, yaml-like format.
Similarly, the active serial assertion can be used for the output instead of the model assertion.
Usage: snap [OPTIONS] model [model-OPTIONS]
Acknowledge warnings
The okay command acknowledges the warnings listed with 'snap warnings'.
Once acknowledged a warning won't appear again unless it re-occurrs and sufficient time has passed.
Pack the given directory as a snap
The pack command packs the given snap-dir as a snap and writes the result to target-dir. If target-dir is omitted, the result is written to current directory. If both source-dir and target-dir are omitted, the pack command packs the current directory.
The default file name for a snap can be derived entirely from its snap.yaml, but in some situations it's simpler for a script to feed the filename in. In those cases, --filename can be given to override the default. If this filename is not absolute it will be taken as relative to target-dir.
When used with --check-skeleton, pack only checks whether snap-dir contains valid snap metadata and raises an error otherwise. Application commands listed in snap metadata file, but appearing with incorrect permission bits result in an error. Commands that are missing from snap-dir are listed in diagnostic messages.
Usage: snap [OPTIONS] pack [pack-OPTIONS]
Enable aliases from a snap, disabling any conflicting aliases
The prefer command enables all aliases of the given snap in preference to conflicting aliases of other snaps whose aliases will be disabled (or removed, for manual ones).
Usage: snap [OPTIONS] prefer [prefer-OPTIONS]
Prepare a device image
The prepare-image command performs some of the steps necessary for creating device images.
For core images it is not invoked directly but usually via ubuntu-image.
For preparing classic images it supports a --classic mode
Usage: snap [OPTIONS] prepare-image [prepare-image-OPTIONS]
Reboot into selected system and mode
The reboot command reboots the system into a particular mode of the selected recovery system.
When called without a system label and without a mode it will just trigger a regular reboot.
When called without a system label but with a mode it will use the current system to enter the given mode.
Note that "recover", "factory-reset" and "run" modes are only available for the current system.
Usage: snap [OPTIONS] reboot [reboot-OPTIONS]
List available recovery systems
The recovery command lists the available recovery systems.
With --show-keys it displays recovery keys that can be used to unlock the encrypted partitions if the device-specific automatic unlocking does not work.
Usage: snap [OPTIONS] recovery [recovery-OPTIONS]
Refresh snaps in the system
The refresh command updates the specified snaps, or all snaps in the system if none are specified.
With no further options, the snaps are refreshed to the current revision of the channel they're tracking, preserving their confinement options. All available channels of a snap are listed in its 'snap info' output.
Revision choice via the --revision override requires the user to have developer access to the snap, either directly or through the store's collaboration feature, and to be logged in (see 'snap help login').
Note a later refresh will typically undo a revision override.
Usage: snap [OPTIONS] refresh [refresh-OPTIONS]
Remove snaps from the system
The remove command removes the named snap instance from the system.
By default all the snap revisions are removed, including their data and the common data directory. When a --revision option is passed only the specified revision is removed.
Unless automatic snapshots are disabled, a snapshot of all data for the snap is saved upon removal, which is then available for future restoration with snap restore. The --purge option disables automatically creating snapshots.
Usage: snap [OPTIONS] remove [remove-OPTIONS]
Restart services
The restart command restarts the given services.
If the --reload option is given, for each service whose app has a reload command, a reload is performed instead of a restart.
Usage: snap [OPTIONS] restart [restart-OPTIONS]
Restore a snapshot
The restore command replaces the current user, system and configuration data of included snaps, with the corresponding data from the specified snapshot.
By default, this command restores all the data in a snapshot. Alternatively, you can specify the data of which snaps to restore, or for which users, or a combination of these.
If a snap is included in a restore operation, excluding its system and configuration data from the restore is not currently possible. This restriction may be lifted in the future.
Usage: snap [OPTIONS] restore [restore-OPTIONS]
Reverts the given snap to the previous state
The revert command reverts the given snap to its state before the latest refresh. This will reactivate the previous snap revision, and will use the original data that was associated with that revision, discarding any data changes that were done by the latest revision. As an exception, data which the snap explicitly chooses to share across revisions is not touched by the revert process.
Usage: snap [OPTIONS] revert [revert-OPTIONS]
Run the given snap command
The run command executes the given snap command with the right confinement and environment.
Usage: snap [OPTIONS] run [run-OPTIONS] <NAME-OF-SNAP>.<NAME-OF-APP> [<SNAP-APP-ARG>...]
Save a snapshot of the current data
The save command creates a snapshot of the current user, system and configuration data for the given snaps.
By default, this command saves the data of all snaps for all users. Alternatively, you can specify the data of which snaps to save, or for which users, or a combination of these.
If a snap is included in a save operation, excluding its system and configuration data from the snapshot is not currently possible. This restriction may be lifted in the future.
Usage: snap [OPTIONS] save [save-OPTIONS]
List currently stored snapshots
The saved command displays a list of snapshots that have been created previously with the 'save' command.
Usage: snap [OPTIONS] saved [saved-OPTIONS]
Query the status of services
The services command lists information about the services specified, or about the services in all currently installed snaps.
Change configuration options
The set command changes the provided configuration options as requested.
$ snap set snap-name username=frank password=$PASSWORD
All configuration changes are persisted at once, and only after the snap's configuration hook returns successfully.
Nested values may be modified via a dotted path:
$ snap set snap-name author.name=frank
Configuration option may be unset with exclamation mark:
$ snap set snap-name author!
Usage: snap [OPTIONS] set [set-OPTIONS]
Start services
The start command starts, and optionally enables, the given services.
Usage: snap [OPTIONS] start [start-OPTIONS]
Stop services
The stop command stops, and optionally disables, the given services.
Usage: snap [OPTIONS] stop [stop-OPTIONS]
Switches snap to a different channel
The switch command switches the given snap to a different channel without doing a refresh. All available channels of a snap are listed in its 'snap info' output.
Usage: snap [OPTIONS] switch [switch-OPTIONS]
List a change's tasks
The tasks command displays a summary of tasks associated with an individual change.
Usage: snap [OPTIONS] tasks [tasks-OPTIONS]
Test an unpacked snap in the system
The try command installs an unpacked snap into the system for testing purposes. The unpacked snap content continues to be used even after installation, so non-metadata changes there go live instantly. Metadata changes such as those performed in snap.yaml will require reinstallation to go live.
If snap-dir argument is omitted, the try command will attempt to infer it if either snapcraft.yaml file and prime directory or meta/snap.yaml file can be found relative to current working directory.
Usage: snap [OPTIONS] try [try-OPTIONS]
Remove a manual alias, or the aliases for an entire snap
The unalias command removes a single alias if the provided argument is a manual alias, or disables all aliases of a snap, including manual ones, if the argument is a snap name.
Usage: snap [OPTIONS] unalias [unalias-OPTIONS]
Remove configuration options
The unset command removes the provided configuration options as requested.
$ snap unset snap-name name address
All configuration changes are persisted at once, and only after the snap's configuration hook returns successfully.
Nested values may be removed via a dotted path:
$ snap unset snap-name user.name
Usage: snap [OPTIONS] unset [unset-OPTIONS]
Show version details
The version command displays the versions of the running client, server, and operating system.
Wait for configuration
The wait command waits until a configuration becomes true.
List warnings
The warnings command lists the warnings that have been reported to the system.
Once warnings have been listed with 'snap warnings', 'snap okay' may be used to silence them. A warning that's been silenced in this way will not be listed again unless it happens again, _and_ a cooldown time has passed.
Warnings expire automatically, and once expired they are forgotten.
Usage: snap [OPTIONS] warnings [warnings-OPTIONS]
Watch a change in progress
The watch command waits for the given change-id to finish and shows progress (if available).
Usage: snap [OPTIONS] watch [watch-OPTIONS]
Show the email the user is logged in with
The whoami command shows the email the user is logged in with.
Please report all bugs with https://bugs.launchpad.net/snapd/+filebug
| 18 May 2023 |