Snapcraft hook support
A hook is an executable file that runs within a snap’s confined environment when a specific action occurs.
The filename of the executable is based on the name of the hook. If this file exists, snapd will execute the file when required by that hook’s action. See Supported snap hooks for more details on which hooks are supported.
Snapcraft can integrate hooks into a snap using two methods:
1. Using a project-wide
The hook executable can be placed in a directory called
snap/hooks relative to where the
snapcraft command is executed. This will typically mean creating a hooks directory in the same directory that contains the snapcraft.yaml file for your project. The following, for example, shows the location of a configure hook executable:
. └── snap ├── hooks │ └── configure └── snapcraft.yaml
Hook executables in
snap/hooks are automatically copied into the snap during Snapcraft’s
prime step (see Parts lifecycle for details).
2. From within snapcraft.yaml
A part within snapcraft.yaml can also generate and install hook executables into
$SNAPCRAFT_PART_INSTALL/snap/hooks/. These are automatically copied into the snap during the
configure-hook: plugin: dump source: configure-again/ organize: configure: snap/hooks/configure
By default, hooks run with no plugs. If a hook needs more privileges, it can use the top-level
hooks attribute in
snapcraft.yaml to request plugs:
hooks: # Top-level YAML attribute, parallel to `apps` configure: # Hook name, corresponds to executable name plugs: [network] # Or any other plugs required by this hook
Hooks are called with no parameters. See Using the snapctl tool for details on the internal command they can use to provide and retrieve data to and from snapd.
Last updated 9 months ago.