List all gear units including dead ones

[wallrj]

I've added the ?all=1 to the gear list url and added a test which demonstrates the effect.

But I'm not entirely sure which extra states are included by making that change.

For example failed units (eg units created with a non-existent docker image name) are listed anyway.

I'm also not sure how units get into the dead state. The example in my test (and the example that @itamarst used in #208 (comment)) recreate the dead state by creating a gear unit using the busybox image which exits immediately with a 0 status code. I'd have thought that systemd would attempt to restart such units a few times before marking them failed, but that doesn't seem to happen.

I also need some guidance around how to wait for the unit-under-test to reach the dead state. I can test the current state using systemctl, but that won't make any sense when running these tests against the FakeGearClient.
Perhaps this particular test should be move to the implementation specific flocker.node.functional.test_gear.GearClientTests case.

Fixes: #208

[itamarst]

Poll docker until the process goes away, maybe?

[itamarst]

Address and merge, or put up for review if you're still not sure about the testing mechanism.

[wallrj]

Thanks @itamarst

• I moved the test to the functional tests
• Added a new Unit.sub_state attribute and populate that from GearClient.list
• I decided not to set a fixed sub_state value in FakeGearClient because I'm not sure what value to choose and the existing tests all pass, so I guess we can cross that bridge in the future.

Not sure whether I need tests for other previously unlisted states given the comment in openshift/geard#228 (comment)

Putting up for another review because I've changed quite a lot.

[wallrj]

I'm also not sure exactly which "stopped" units were already being listed, prior to this change. In http://lists.openshift.redhat.com/openshift-archives/users/2014-July/msg00006.html the implication is that units that "stop cleanly" wouldn't normally be listed, but actually we've already got a test for units that have been explicitly stopped via the Gear API. I guess in that case (that test) the systemd unit exits with a non-zero code:

• https://github.com/ClusterHQ/flocker/blob/list-all-units-208/flocker/node/functional/test_gear.py#L151-L189

[wallrj]

Ok. I'm going to merge after discussion with @itamarst

Richard Wall: When I moved the test to the functional test case i noticed you'd already got a test for the stopped case.

Richard Wall: And whether adding an attribute for the substate is necessary in this branch....

Richard Wall: Maybe i should wait until you';ve had a chance to review those changes.

Itamar Turner-Trauring: adding substate probably doesn't hurt

Itamar Turner-Trauring: I skimmed the branch, it seemed fine

Itamar Turner-Trauring: I would say that testing all states is useful, but not strictly necessary for now since we're not dealing with all edge cases

Richard Wall: Ok, great. Well I'll merge it then.