"local" charm schema should allow deploying previously deployed local charms

[Katherine Cox-Buday]

As part of the work to make deploying local charms easier, we removed the "local:" schema in favor of relative-path notation (e.g. juju deploy ./foo) and declaring the supported series in metadata.yaml.

However, we still store local charms in Juju's database using the "local:" notation.

We should re-enable utilizing the "local:" schema when deploying charms, but change the meaning to be "deploy this charm which should already exist in the controller".

[Tim Van Steenburgh (tvansteenburgh)]

Will this change allow me to upload a charm to a model and then deploy it via the api using a 'local:' charm-url?

[Richard Harding (rharding)]

@tim yes the plan is that this will enable exactly that.

[Tim Van Steenburgh (tvansteenburgh)]

Here's a python script to repro. You'll need the latest lp:python-jujuclient, which you can install from source or from ppa:tvansteenburgh/ppa.

tvansteenburgh@xenial-vm:~/python-jujuclient⟫ cat deploy_test.py
#!/usr/bin/env python3

import logging
import ssl

from jujuclient.juju2.environment import Environment

log = logging.getLogger(__name__)

# Constants, change these for your environment
API_SERVER = '10.0.4.52'
USER = 'user-admin'
PASSWORD = 'd7247825e7df512140005cb2b6aab925'
CHARM_DIR = '/home/tvansteenburgh/src/charms/trusty/ubuntu'

if __name__ == "__main__":
    logging.basicConfig(level=logging.DEBUG)

    # Login to controller
    endpoint = 'wss://%s:17070' % (API_SERVER)
    controller = Environment(endpoint)
    controller.login(PASSWORD, user=USER)

    # Login to default model
    models = controller.models.list()
    for m in models['user-models']:
        if m['model']['name'] == 'default':
            model_endpoint = '{}/model/{}/api'.format(
                endpoint, m['model']['uuid'])
            model = Environment(model_endpoint)
            model.login(PASSWORD, user=USER)

    # Workaround for certificatge failure (hack)
    ssl._create_default_https_context = ssl._create_unverified_context

    # Upload a local charm to the model
    res = model.add_local_charm_dir(CHARM_DIR, "trusty")
    log.debug("Added local charm: %s", res)

    # Turn on rpc debugging so we can see raw api calls
    model._debug = True

    # Deploy the uploaded charm
    res = model.deploy('mycharm', res['charm-url'])
    log.debug("Deploy response: %s", res)

And here's the output of running it. As you can see, the local charm is uploaded successfully and we get a charm-url back, but then when we try to deploy the charm using that url, it doesn't work:

tvansteenburgh@xenial-vm:~/python-jujuclient⟫ .tox/py27/bin/python deploy_test.py
DEBUG:__main__:Added local charm: {u'charm-url': u'local:trusty/ubuntu-3'}
DEBUG:jujuclient.rpc:rpc request:
{
  "params": {
    "applications": [
      {
        "placement": [],
        "num-units": 1,
        "application": "mycharm",
        "charm-url": "local:trusty/ubuntu-3",
        "config": {},
        "constraints": {}
      }
    ]
  },
  "request-id": 2,
  "version": 1,
  "request": "Deploy",
  "type": "Application"
}
DEBUG:jujuclient.rpc:rpc response:
{
  "request-id": 2,
  "response": {
    "results": [
      {
        "error": {
          "message": "charm \"local:trusty/ubuntu-3\" not found",
          "code": "not found"
        }
      }
    ]
  }
}
DEBUG:__main__:Deploy response: {u'results': [{u'error': {u'message': u'charm "local:trusty/ubuntu-3" not found', u'code': u'not found'}}]}

[Katherine Cox-Buday (cox-katherine-e)]

@timvansteenburgh: I think you're tracking the wrong bug. Your issue looks to do with deploying a local charm from the filesystem. This bug is to deploy pre-deployed local charms from the controller, e.g.: `juju deploy local:xenial/foo-0 bar`

To everyone else:

I have this working, but it looks like there are some oddities both with placement and removing applications. E.g.

1. If I `juju deploy local:xenial/foo-0 bar`, the application is added, but no machine/container is provisioned
2. If I `juju remove-application bar`, I get an error "ERROR charm "local:xenial/bar" not found (not found)", but the application is removed successfully.
3. If I remove all the applications referencing this charm, I can still redeploy the charm from the controller (i.e. it's not being cleaned up). This is likely being addressed by another round of bug fixes, but is worth noting.

I need to investigate these to determine whether it's worth landing this with outstanding bugs. Because of that, this may not make b16. I'll post the decision in ~3h.

[Katherine Cox-Buday (cox-katherine-e)]

PR here: https://github.com/juju/juju/pull/6087

I think I've solved all the issues.