How can I deploy my local Juju Charm with Amulet framework?

Question

I use amulet as testing framework for charms which we developing. I've already tried to reproduce an example, provided on https://jujucharms.com/docs/stable/tools-amulet and it's work fine. But now I'm trying to do the same basic setup for charm, which was developed and stored on hard drive ('cf-nats' charm was cloned from github). Here the list of my actions (I use local environment for deploying):

Python 3.2.3 (default, Feb 27 2014, 21:31:18) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> import amulet
>>> import requests
>>> d = amulet.Deployment(series='trusty')
>>> d.add('cf-nats', charm = '/home/ubuntu/cf-charms/charms/trusty/cf-nats')
>>> d.setup()

And I got the next output:

2014-03-10 10:56:09 Starting deployment of local
Traceback (most recent call last):
  File "/usr/bin/juju-deployer", line 9, in <module>
    load_entry_point('juju-deployer==0.2.5', 'console_scripts', 'juju-deployer')()
  File "/usr/lib/python2.7/dist-packages/deployer/cli.py", line 118, in main
    run()
  File "/usr/lib/python2.7/dist-packages/deployer/cli.py", line 204, in run
    importer.Importer(env, deployment, options).run()
  File "/usr/lib/python2.7/dist-packages/deployer/action/importer.py", line 142, in run
    self.get_charms()
  File "/usr/lib/python2.7/dist-packages/deployer/action/importer.py", line 47, in get_charms
    no_local_mods=self.options.no_local_mods)
  File "/usr/lib/python2.7/dist-packages/deployer/deployment.py", line 112, in fetch_charms
    charm.fetch()
  File "/usr/lib/python2.7/dist-packages/deployer/charm.py", line 98, in fetch
    self.vcs.branch()
AttributeError: 'NoneType' object has no attribute 'branch'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/amulet/deployer.py", line 175, in setup
    self.juju_env], cwd=self.deployer_dir)
  File "/usr/lib/python3.2/subprocess.py", line 489, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['juju-deployer', '-W', '-c', '/tmp/amulet-juju-deployer-myb41r.json', '-e', 'local', 'local']' returned non-zero exit status 1

I've also tried to deploy the same charm manualy with juju command line interface and it's work.

Here is the output from d.schema()

>>> d.schema()
{'local': {'services': {'cf-nats-sentry': {'_has_sentry': True, 'expose': True, 'branch': '/tmp/sentry-sub_16ocg4/cf-nats-sentry'}, 'cf-nats': {'_has_sentry': True, 'branch': '/home/ubuntu/cf-charms/charms/trusty/cf-nats'}, 'relation-sentry': {'expose': True, 'branch': '/tmp/sentry_5cdg4t/relation-sentry'}}, 'series': 'trusty', 'relations': [['cf-nats:juju-info', 'cf-nats-sentry:juju-info']]}}

What is wrong in my code? How can I deploy my local charm with amulet framework? What kind of python packages should be installed?

Thank you in advance.

Answer 1

I believe I see your problem. So, you pulled this charm from github which is fine. However, tests are usually written and run from within the tests directory. So, amulet applies a little bit of magic to deploy using the charm on disk so you don't have to explicitly put charm= in the d.add line. However, since you're running from interactive shell it makes sense for you to do this. The problem is, it's not a Bazaar branch which is what Juju Deployer is expecting.

Typically, what happens, when you just do d.add('cf-nats') in a charm test, the charm tree gets copied to a temporary location, and a bzr repo is created (if one doesn't exist already). Then that new temp location is fed to deployer. However, since you've given it a firm file path that part isn't happening (by design) and it assumes you have a charm that has a bzr repo and it's just going to use that.

The way around this is to either run export JUJU_TEST_CHARM="cf-nats" (and environment variable the juju test plugin sets) prior to launching your Python3 shell from the $CHARM_DIR (/home/ubuntu/cf-charms/charms/trusty/cf-nats) or after creating d = amulet.Deployment() set d.charm_name = 'cf-nats'. Then just do d.add('cf-nats'), amulet will see that the basename of getcwd is the same as the charm name and transparently perform it's little bit of magic.

That should do it. Ideally, adding support for git based charms to juju deployer will resolve all of this, but try that and let me know if it doesn't work for you.