[1.9] Multiple negative spaces constraints given and rejected by MAAS

[Martin Packman]

Juju 2.0 translates a constraint that a machine must be in neither of two spaces into a not_networks parameter that MAAS 1.9 rejects.

With two spaces, each with one subnet (here gz-test -> 10.0.50.0/24 and gz-test-b -> 10.0.60.0/24) juju accepts a constraint that a machine should be in neither space, which is rejected by MAAS 1.9 on acquire:

$ juju bootstrap munna-vmaas --config test-mode=true --bootstrap-constraints="spaces=^gz-test,^gz-test-b" --debug
19:29:36 INFO juju.cmd supercommand.go:63 running juju [2.0.1 gc go1.6.2]
...
19:29:37 INFO juju.cmd.juju.commands bootstrap.go:744 combined bootstrap constraints: spaces=^gz-test,^gz-test-b
...
19:29:49 ERROR cmd supercommand.go:458 failed to bootstrap model: cannot start bootstrap instance: cannot run instances: cannot run instances: ServerError: 400 BAD REQUEST ({"not_networks": ["No matching subnets found."]})

From the maas.log for this machine:

Oct 26 19:30:11 deafening-thrill maas.api: [INFO] Request from user root to acquire a node with constraints <QueryDict: {u'agent_name': [u'01bce9c6-1a51-468a-84ac-d4a37b390f9d'], u'zone': [u'default'], u'not_networks': [u'space:3,space:4']}>

See bug 1636919 for related constraint issue with MAAS 2.0+ accepting but ignoring parameters.

[Andres Rodriguez (andreserl)]

Martin,

Can you confirm the exact version of MAAS please?

[Martin Packman (gz)]

Sure, see the terminal session, it's "1.9.4+bzr4592-0ubuntu1".

[Mike Pontillo (mpontillo)]

Note that in MAAS 2.0 the 'networks' constraint was renamed to 'subnets' to match the new terminology for the network model, but otherwise, this code hasn't changed. (this is a separate bug.)

I wrote a test case to ensure that this behaves as-expected in MAAS[1], but long story short: you cannot use a comma to separate parameters when using the not_networks (MAAS 1.9) or not_subnets (MAAS 2.x+) constraint.

When making the API request, you must pass in something like:

.../node/?op=acquire&not_subnets=space:x&not_subnets=space:y

Whereas juju is passing in:

.../node?op=aquire&not_subnets=space:x,space:y

The comma syntax is not supported for these 'legacy' constraints, though they are supported according to the spec in the new 'interfaces' constraint.

[1]:
https://code.launchpad.net/~mpontillo/maas/multiple-subnet-constraints--bug-1636969/+merge/309402

[Martin Packman (gz)]

Okay, so this bug can just be about splitting into multiple params as MAAS requires. I filed bug 1637182 about the MAAS documentation here.

[Mike Pontillo (mpontillo)]

Note: the errant "Fix Committed" from the lander was just me committing a unit test to make sure we don't break this in the future. No fix was necessary.