Incorrect series used during upgrade to a local charm and no way to specify it manually

[Dmitrii Shcherbakov]

Scenario:

1. I want to use a local version of a charm with an applied patch. A non-patched version is already deployed;

2. The charm supports different series including trusty;

3. The deployed version is of a 'trusty' series;

4. juju upgrade-charm --path <p> fails

ubuntu@maas:~⟫ juju status keystone
Model Controller Cloud/Region Version
default foundations-controller cpe 2.1.1

App Version Status Scale Charm Store Rev OS Notes
keystone 9.2.0 active 3 keystone jujucharms 0 ubuntu
keystone-hacluster active 3 hacluster jujucharms 33 ubuntu

Unit Workload Agent Machine Public address Ports Message
keystone/0 active idle 3/lxd/6 172.16.10.41 5000/tcp Unit is ready
  keystone-hacluster/2 active idle 172.16.10.41 Unit is ready and clustered
keystone/1* active idle 1/lxd/7 172.16.10.35 5000/tcp Unit is ready
  keystone-hacluster/0* active idle 172.16.10.35 Unit is ready and clustered
keystone/3 active idle 2/lxd/12 172.16.10.5 5000/tcp Unit is ready
  keystone-hacluster/3 active idle 172.16.10.5 Unit is ready and clustered

Machine State DNS Inst id Series AZ
1 started 172.16.10.253 fkrbrg trusty default
1/lxd/7 started 172.16.10.35 juju-43d9c4-1-lxd-7 trusty
2 started 172.16.10.2 fxxtes trusty default
2/lxd/12 started 172.16.10.5 juju-43d9c4-2-lxd-12 trusty
3 started 172.16.10.3 sph73g trusty default
3/lxd/6 started 172.16.10.41 juju-43d9c4-3-lxd-6 trusty

...

ubuntu@maas:~⟫ juju config keystone | grep -P 'openstack-origin:|trusty-mitaka'
  openstack-origin:
    value: cloud:trusty-mitaka

# upgrade fails

ubuntu@maas:~⟫ juju upgrade-charm keystone --path ~/build/charm-keystone
Added charm "local:xenial/keystone-1" to the model.
ERROR cannot upgrade application "keystone" to charm "local:xenial/keystone-1": cannot change an application's series

# the charm supports multiple series, trusty included
1 ubuntu@maas:~⟫ grep -P 'xenial|trusty|yakkety|zesty' ~/build/charm-keystone/metadata.yaml
  - xenial
  - zesty
  - trusty
  - yakkety

# shouldn't have to but
ubuntu@maas:~⟫ juju upgrade-charm keystone --path ~/build/charm-keystone --force-series
Added charm "local:xenial/keystone-2" to the model.
ERROR cannot upgrade application "keystone" to charm "local:xenial/keystone-2": cannot change an application's series

If I remove older versions from metadata.yaml it deploys just fine.

ubuntu@maas:~⟫ sed -i -e '/- xenial/d' ~/build/charm-keystone/metadata.yaml
ubuntu@maas:~⟫ juju upgrade-charm keystone --path ~/build/charm-keystone
Added charm "local:zesty/keystone-0" to the model.
ERROR cannot upgrade application "keystone" to charm "local:zesty/keystone-0": cannot change an application's series

# note that I haven't deleted yakkety and it is below zesty and xenial. It worked due to the order of processing

ubuntu@maas:~⟫ cat ~/build/charm-keystone/metadata.yaml | grep series -A3
series:
  - trusty
  - yakkety
extra-bindings:

ubuntu@maas:~⟫ juju upgrade-charm keystone --path ~/build/charm-keystone
Added charm "local:trusty/keystone-0" to the model.

[John A Meinel (jameinel)]

So the issue is that when doing "juju upgrade-charm --path" we are inferring what series we should use as the "default" series from the charm, which is always the first item listed in the series.

So if you move "trusty" to be the first series in the series list, then it should work (you shouldn't have to remove xenial, just switch trusty to be the first item).

We should have 'upgrade-charm' know what series the existing application is, and check if its one of the supported series from the charm, and if so, use it. Rather than only supporting the default series.

[John A Meinel (jameinel)]

see a similar (but not exactly the same) bug #1663510 about 'juju deploy' not using model-config default-series over the default series in the charm itself.