Ubuntu Manpage: snap - Tool to interact with snaps

NAME

       snap - Tool to interact with snaps

SYNOPSIS

       snap [OPTIONS]

DESCRIPTION

       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.

OPTIONS

COMMANDS

abort
Abort a pending change

The abort command attempts to abort a change that still has pending tasks.

Usage: snap abort [abort-OPTIONS]

--last Select last change of given type (install, refresh, remove, try, auto-refresh,
etc.). A question mark at the end of the type means to do nothing (instead of
returning an error) if no change of the given type is found. Note the question mark
could need protecting from the shell.

ack
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.

alias
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 alias [alias-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

aliases
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'.

changes
List system changes

The changes command displays a summary of system changes performed recently.

Usage: snap changes [changes-OPTIONS]

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display relative times up
to 60 days, then YYYY-MM-DD.

check-snapshot
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 check-snapshot [check-snapshot-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--users
Check data of only specific users (comma-separated) (default: all users)

connect
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 connect [connect-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

connections
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 connections [connections-OPTIONS]

--all Show connected and unconnected plugs and slots

disable
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 disable [disable-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

disconnect
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.

Usage: snap disconnect [disconnect-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

download
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 download [download-OPTIONS]

--channel
Use this channel instead of stable

--edge Install from the edge channel

--beta Install from the beta channel

--candidate
Install from the candidate channel

--stable
Install from the stable channel

--revision
Download the given revision of a snap, to which you must have developer access

enable
Enable a snap in the system

The enable command enables a snap that was previously disabled.

Usage: snap enable [enable-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

find
Find packages to install

The find command queries the store for available packages in the stable channel.

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 find [find-OPTIONS]

Aliases: search

--private
Search private snaps

--narrow
Only search for snaps in “stable”

--section [="show-all-sections-please"] <default: "no-section-specified">
Restrict the search to a given section

--color <default: "auto">
Use a little bit of color to highlight some things.

--unicode <default: "auto">
Use a little bit of Unicode to improve legibility.

forget
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 forget [forget-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

get
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, a document is returned:

$ snap get snap-name username password
{
"username": "frank",
"password": "..."
}

Nested values may be retrieved via a dotted path:

$ snap get snap-name author.name
frank

Usage: snap get [get-OPTIONS]

-t Strict typing with nulls and quoted strings

-d Always return document, even with single key

-l Always return list, even with single key

help
Show help about a command

The help command displays information about snap commands.

Usage: snap help [help-OPTIONS]

--all Show a short summary of all commands

info
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 info [info-OPTIONS]

--color <default: "auto">
Use a little bit of color to highlight some things.

--unicode <default: "auto">
Use a little bit of Unicode to improve legibility.

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display relative times up
to 60 days, then YYYY-MM-DD.

--verbose
Include more details on the snap (expanded notes, base, etc.)

install
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.

Revision choice via the --revision override requires the 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, 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 install [install-OPTIONS]

--color <default: "auto">
Use a little bit of color to highlight some things.

--unicode <default: "auto">
Use a little bit of Unicode to improve legibility.

--no-wait
Do not wait for the operation to finish but just print the change id.

--channel
Use this channel instead of stable

--edge Install from the edge channel

--beta Install from the beta channel

--candidate
Install from the candidate channel

--stable
Install from the stable channel

--devmode
Put snap in development mode and disable security confinement

--jailmode
Put snap in enforced confinement mode

--classic
Put snap in classic mode and disable security confinement

--revision
Install the given revision of a snap, to which you must have developer access

--dangerous
Install the given snap file even if there are no pre-acknowledged signatures for
it, meaning it was not verified and could be dangerous (--devmode implies this)

--unaliased
Install the given snap without enabling its automatic aliases

--name Install the snap file under the given instance name

interface
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 interface [interface-OPTIONS]

--attrs
Show interface attributes

--all Include unused interfaces

interfaces
List interfaces' slots and plugs

The interfaces command lists interfaces available in the system.

By default all slots and plugs, used and offered by all snaps, are displayed.

$ snap interfaces <snap>:<slot or plug>

Lists only the specified slot or plug.

$ snap interfaces <snap>

Lists the slots offered and plugs used by the specified snap.

$ snap interfaces -i=<interface> [<snap>]

Filters the complete output so only plugs and/or slots matching the provided details are
listed.

Usage: snap interfaces [interfaces-OPTIONS]

-i Constrain listing to specific interfaces

known
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 known [known-OPTIONS]

--remote

list
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 list [list-OPTIONS]

--all Show all revisions

--color <default: "auto">
Use a little bit of color to highlight some things.

--unicode <default: "auto">
Use a little bit of Unicode to improve legibility.

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 purchasing
of snaps using 'snap buy', 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

logout
Log out of snapd and the store

The logout command logs the current user out of snapd and the store.

logs
Retrieve logs for services

The logs command fetches logs of the given services and displays them in chronological
order.

Usage: snap logs [logs-OPTIONS]

-n <default: "10">
Show only the given number of lines, or 'all'.

-f Wait for new lines and print them as they come in.

okay
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
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 pack [pack-OPTIONS]

--check-skeleton
Validate snap-dir metadata only

--filename
Output to this filename

prefer
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 prefer [prefer-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

prepare-image
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 prepare-image [prepare-image-OPTIONS]

--classic
Enable classic mode to prepare a classic model image

--arch Specify an architecture for snaps for --classic when the model does not

--channel <default: "stable">
The channel to use

--snap <snap>[=<channel>]
Include the given snap from the store or a local file and/or specify the channel to
track for the given snap

refresh
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.

Note a later refresh will typically undo a revision override.

Usage: snap refresh [refresh-OPTIONS]

--color <default: "auto">
Use a little bit of color to highlight some things.

--unicode <default: "auto">
Use a little bit of Unicode to improve legibility.

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display relative times up
to 60 days, then YYYY-MM-DD.

--no-wait
Do not wait for the operation to finish but just print the change id.

--channel
Use this channel instead of stable

--edge Install from the edge channel

--beta Install from the beta channel

--candidate
Install from the candidate channel

--stable
Install from the stable channel

--devmode
Put snap in development mode and disable security confinement

--jailmode
Put snap in enforced confinement mode

--classic
Put snap in classic mode and disable security confinement

--amend
Allow refresh attempt on snap unknown to the store

--revision
Refresh to the given revision, to which you must have developer access

--list Show the new versions of snaps that would be updated with the next refresh

--time Show auto refresh information but do not perform a refresh

--ignore-validation
Ignore validation by other snaps blocking the refresh

remove
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.

Usage: snap remove [remove-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--revision
Remove only the given revision

restart
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 restart [restart-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--reload
If the service has a reload command, use it instead of restarting.

restore
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 restore [restore-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--users
Restore data of only specific users (comma-separated) (default: all users)

revert
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 revert [revert-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--devmode
Put snap in development mode and disable security confinement

--jailmode
Put snap in enforced confinement mode

--classic
Put snap in classic mode and disable security confinement

--revision
Revert to the given revision

run
Run the given snap command

The run command executes the given snap command with the right confinement and
environment.

Usage: snap run [run-OPTIONS]

--shell
Run a shell instead of the command (useful for debugging)

--strace [="with-strace"] <default: "no-strace">
Run the command under strace (useful for debugging). Extra strace options can be
specified as well here. Pass --raw to strace early snap helpers.

--gdb Run the command with gdb

--trace-exec
Display exec calls timing data

save
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 save [save-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display short relative
times.

--users
Snapshot data of only specific users (comma-separated) (default: all users)

saved
List currently stored snapshots

The saved command displays a list of snapshots that have been created previously with the
'save' command.

Usage: snap saved [saved-OPTIONS]

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display short relative
times.

--id Show only a specific snapshot.

services
Query the status of services

The services command lists information about the services specified, or about the services
in all currently installed snaps.

set
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 author.name=frank

Usage: snap set [set-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

start
Start services

The start command starts, and optionally enables, the given services.

Usage: snap start [start-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--enable
As well as starting the service now, arrange for it to be started on boot.

stop
Stop services

The stop command stops, and optionally disables, the given services.

Usage: snap stop [stop-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--disable
As well as stopping the service now, arrange for it to no longer be started on
boot.

switch
Switches snap to a different channel

The switch command switches the given snap to a different channel without doing a refresh.

Usage: snap switch [switch-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--channel
Use this channel instead of stable

--edge Install from the edge channel

--beta Install from the beta channel

--candidate
Install from the candidate channel

--stable
Install from the stable channel

tasks
List a change's tasks

The tasks command displays a summary of tasks associated with an individual change.

Usage: snap tasks [tasks-OPTIONS]

Aliases: change

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display relative times up
to 60 days, then YYYY-MM-DD.

try
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 try [try-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

--devmode
Put snap in development mode and disable security confinement

--jailmode
Put snap in enforced confinement mode

--classic
Put snap in classic mode and disable security confinement

unalias
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 unalias [unalias-OPTIONS]

--no-wait
Do not wait for the operation to finish but just print the change id.

version
Show version details

The version command displays the versions of the running client, server, and operating
system.

wait
Wait for configuration

The wait command waits until a configuration becomes true.

warnings
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 warnings [warnings-OPTIONS]

--abs-time
Display absolute times (in RFC 3339 format). Otherwise, display relative times up
to 60 days, then YYYY-MM-DD.

--all Show all warnings

--verbose
Show more information

watch
Watch a change in progress

The watch command waits for the given change-id to finish and shows progress (if
available).

Usage: snap watch [watch-OPTIONS]

whoami
Show the email the user is logged in with

The whoami command shows the email the user is logged in with.

25 March 2019 snap(8)