Snapcraft extensions enable snap developers to easily incorporate a set of common requirements into a snap.
These requirements can include build and staging packages, plugs and interfaces, file layouts and environments, and whatever other snapcraft.yaml elements may be required to build a functioning system.
A snap developer creating a GTK 3 application snap, for example, can use the
gnome-3-28 extension to expose the GTK 3 libraries to a snap at build and runtime without the snap developer needing specific deep knowledge about GTK 3.
- avoid repetitive tasks in the snap building process
- obviate the need for in-depth knowledge of the target software stack
- create a standard template for common application requirements
- reduce the testing and security burden, as they’re tested and updated independently
For a full list of supported extensions, see Supported extensions.
To use an extension, the app metadata section of the snap’s snapcraft.yaml needs include the
extensions definition. The following snippet, for example, shows how the Firefox snap uses the
gnome-3-34 extension to add Gnome desktop support:
apps: firefox: command: firefox command-chain: [tmpdir] desktop: distribution/firefox.desktop extensions: [gnome-3-34] [...]
All extensions are included with Snapcraft and can be listed with the following command:
$ snapcraft extensions Extension name Supported bases ---------------- ----------------- gnome-3-28 core18 gnome-3-38 core20 kde-neon core18, core20 [...]
See Supported Extensions for the full list of extensions.
Further information about any specific extension can be obtained by typing
snapcraft extension followed by the extension name:
$ snapcraft extension gnome-3-28 This extension eases creation of snaps that integrate with GNOME 3.28 ...
Extensions modify the
snapcraft.yaml definition before a build. You can use the
expand-extensions command from your project’s root directory to see how the
snapcraft.yaml file will look with the extensions applied.
$ snapcraft expand-extensions name: foliate ... layout: /usr/lib/$SNAPCRAFT_ARCH_TRIPLET/webkit2gtk-4.0: bind: $SNAP/gnome-platform/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/webkit2gtk-4.0 /usr/share/xml/iso-codes: bind: $SNAP/gnome-platform/usr/share/xml/iso-codes apps: foliate: command: usr/bin/com.github.johnfactotum.Foliate plugs: - gsettings - home - desktop - desktop-legacy - wayland - x11 slots: - dbus-daemon common-id: com.github.johnfactotum.Foliate.desktop desktop: usr/share/applications/com.github.johnfactotum.Foliate.desktop command-chain: - snap/command-chain/desktop-launch ...
Last updated 4 months ago.