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# Copyright 2014-2015 Canonical Limited.
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# This file is part of charm-helpers.
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# charm-helpers is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License version 3 as
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# published by the Free Software Foundation.
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# charm-helpers is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public License
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# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
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# Copyright 2013 Canonical Ltd.
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# Charm Helpers Developers <juju@lists.ubuntu.com>
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"""Charm Helpers ansible - declare the state of your machines.
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This helper enables you to declare your machine state, rather than
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program it procedurally (and have to test each change to your procedures).
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Your install hook can be as simple as::
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import charmhelpers.contrib.ansible
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charmhelpers.contrib.ansible.install_ansible_support()
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charmhelpers.contrib.ansible.apply_playbook('playbooks/install.yaml')
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and won't need to change (nor will its tests) when you change the machine
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All of your juju config and relation-data are available as template
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variables within your playbooks and templates. An install playbook looks
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- name: Add private repositories.
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src: ../templates/private-repositories.list.jinja2
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dest: /etc/apt/sources.list.d/private.list
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- name: Update the cache.
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- name: Install dependencies.
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group: name={{ item.name }} gid={{ item.gid }}
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- { name: 'deploy_user', gid: 1800 }
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- { name: 'service_user', gid: 1500 }
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Read more online about `playbooks`_ and standard ansible `modules`_.
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.. _playbooks: http://www.ansibleworks.com/docs/playbooks.html
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.. _modules: http://www.ansibleworks.com/docs/modules.html
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A further feature os the ansible hooks is to provide a light weight "action"
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scripting tool. This is a decorator that you apply to a function, and that
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function can now receive cli args, and can pass extra args to the playbook.
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def some_action(amount, force="False"):
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"Usage: some-action AMOUNT [force=True]" # <-- shown on error
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# process the arguments
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# return extra-vars to be passed to ansible-playbook
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'amount': int(amount),
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You can now create a symlink to hooks.py that can be invoked like a hook, but
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# link actions/some-action to hooks/hooks.py
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actions/some-action amount=10 force=true
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import charmhelpers.contrib.templating.contexts
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import charmhelpers.core.host
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import charmhelpers.core.hookenv
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import charmhelpers.fetch
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charm_dir = os.environ.get('CHARM_DIR', '')
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ansible_hosts_path = '/etc/ansible/hosts'
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# Ansible will automatically include any vars in the following
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# file in its inventory when run locally.
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ansible_vars_path = '/etc/ansible/host_vars/localhost'
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def install_ansible_support(from_ppa=True, ppa_location='ppa:rquillo/ansible'):
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"""Installs the ansible package.
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By default it is installed from the `PPA`_ linked from
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the ansible `website`_ or from a ppa specified by a charm config..
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.. _PPA: https://launchpad.net/~rquillo/+archive/ansible
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.. _website: http://docs.ansible.com/intro_installation.html#latest-releases-via-apt-ubuntu
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If from_ppa is empty, you must ensure that the package is available
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from a configured repository.
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charmhelpers.fetch.add_source(ppa_location)
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charmhelpers.fetch.apt_update(fatal=True)
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charmhelpers.fetch.apt_install('ansible')
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with open(ansible_hosts_path, 'w+') as hosts_file:
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hosts_file.write('localhost ansible_connection=local')
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def apply_playbook(playbook, tags=None, extra_vars=None):
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tags = ",".join(tags)
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charmhelpers.contrib.templating.contexts.juju_state_to_yaml(
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ansible_vars_path, namespace_separator='__',
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allow_hyphens_in_keys=False, mode=(stat.S_IRUSR | stat.S_IWUSR))
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# we want ansible's log output to be unbuffered
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env = os.environ.copy()
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env['PYTHONUNBUFFERED'] = "1"
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call.extend(['--tags', '{}'.format(tags)])
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extra = ["%s=%s" % (k, v) for k, v in extra_vars.items()]
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call.extend(['--extra-vars', " ".join(extra)])
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subprocess.check_call(call, env=env)
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class AnsibleHooks(charmhelpers.core.hookenv.Hooks):
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"""Run a playbook with the hook-name as the tag.
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This helper builds on the standard hookenv.Hooks helper,
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but additionally runs the playbook with the hook-name specified
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using --tags (ie. running all the tasks tagged with the hook-name).
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hooks = AnsibleHooks(playbook_path='playbooks/my_machine_state.yaml')
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# All the tasks within my_machine_state.yaml tagged with 'install'
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# will be run automatically after do_custom_work()
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# For most of your hooks, you won't need to do anything other
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# than run the tagged tasks for the hook:
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@hooks.hook('config-changed', 'start', 'stop')
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def just_use_playbook():
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# As a convenience, you can avoid the above noop function by specifying
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# the hooks which are handled by ansible-only and they'll be registered
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# hooks = AnsibleHooks(
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# 'playbooks/my_machine_state.yaml',
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# default_hooks=['config-changed', 'start', 'stop'])
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if __name__ == "__main__":
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# execute a hook based on the name the program is called by
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hooks.execute(sys.argv)
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def __init__(self, playbook_path, default_hooks=None):
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"""Register any hooks handled by ansible."""
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super(AnsibleHooks, self).__init__()
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self.playbook_path = playbook_path
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default_hooks = default_hooks or []
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def noop(*args, **kwargs):
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for hook in default_hooks:
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self.register(hook, noop)
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def register_action(self, name, function):
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"""Register a hook"""
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self._actions[name] = function
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def execute(self, args):
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"""Execute the hook followed by the playbook using the hook as tag."""
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hook_name = os.path.basename(args[0])
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if hook_name in self._actions:
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extra_vars = self._actions[hook_name](args[1:])
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super(AnsibleHooks, self).execute(args)
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charmhelpers.contrib.ansible.apply_playbook(
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self.playbook_path, tags=[hook_name], extra_vars=extra_vars)
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def action(self, *action_names):
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"""Decorator, registering them as actions"""
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def action_wrapper(decorated):
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@functools.wraps(decorated)
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kwargs = dict(arg.split('=') for arg in argv)
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return decorated(**kwargs)
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except TypeError as e:
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if decorated.__doc__:
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e.args += (decorated.__doc__,)
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self.register_action(decorated.__name__, wrapper)
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if '_' in decorated.__name__:
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self.register_action(
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decorated.__name__.replace('_', '-'), wrapper)
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return action_wrapper
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removed
hooks/charmhelpers/contrib/ansible/__init__.py
