support juju actions directly

[Paul Collins]

Mojo should support Juju actions directly. [half-baked design ideas elided]

Pre-2.2 actions were a little awkward to use, since "juju run-action" would exit immediately and the operator had to poll Juju until it had completed. Since 2.2, these various action-related commands have a --wait option (with a timeout!) that Mojo could use.

Juju pre-2.2 could be supported more easily by importing Stuart Bishop's juju-act plugin (lp:juju-act) but I imagine that Juju 2.2 will become the version most folks use fairly quickly.

[Tom Haddon (mthaddon)]

Without getting into design ideas, can you give me an idea of how you see this working? Would it be a phase to run a juju action? What would you do with the output?

[Paul Collins (pjdc)]

The actions I presently want to invoke are

juju run-action postgresql/0 wal-e-backup --wait
juju run-action postgresql/0 wal-e-restore --wait storage-uri=swift://staging-vault-postgresql-wal-e-backup/ confirm=true

In a manifest, these actions could look something like this:

juju-run-action postgresql wal-e-backup
juju-run-action postgresql wal-e-restore storage-uri=swift://staging-vault-postgresql-wal-e-backup/ confirm=true

I imagine it would behave like the script phase: log the results, continue on success. It'd also be helpful if you could specify just the application name to let Mojo pick a unit, since in operational cases we may not know which units will exist when we write the manifest. More complex cases that require doing something with the action's results should probably just be regular scripts.