Hook

In Juju, a hook is a notification from the controller agent through the unit agent to the charm that the internal representation of Juju has changed in a way that requires a reaction from the charm so that the unit’s state and the controller’s state can be reconciled.

In the charm SDK, in Ops, Juju hooks are translated into Ops events = ‘events’, specifically, into classes that inherit from HookEvent.

Contents:

• List of hooks

List of hooks

Source

• <action name>-action
• <container>-pebble-change-updated
• <container>-pebble-check-failed (starting with Juju 3.6)
• <container>-pebble-check-recovered (starting with Juju 3.6)
• <container>-pebble-custom-notice
• <container>-pebble-ready
• <endpoint>-relation-broken
• <endpoint>-relation-changed
• <endpoint>-relation-created
• <endpoint>-relation-departed
• <endpoint>-relation-joined
• <storage>-storage-attached
• <storage>-storage-detaching
• collect-metrics
• config-changed
• install
• leader-deposed
• leader-elected
• leader-settings-changed
• meter-status-changed
• post-series-upgrade (removed starting with Juju 4)
• pre-series-upgrade (removed starting with Juju 4)
• remove
• secret-changed

Triggered by Juju on a secret’s observer when the secret’s owner changes the secret’s contents.

• secret-expired

Currently supported only for charm secrets.

Triggered by Juju on a secret’s owner when a secret’s expiration time elapses.

• secret-remove

Currently supported only for charm secrets.

Triggered by Juju on a secret’s owner when one of the secret’s revisions can be removed.

• secret-rotate

Currently supported only for charm secrets.

Triggered by Juju on a secret’s owner when the secret’s rotation policy elapses .

• start
• stop
• update-status
• upgrade-charm

Contributors: @anvial, @hmlanigan, @ppasotti , @simonrichardson, @tmihoc