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  • Committer: Michael Nelson
  • Date: 2015-10-27 23:27:18 UTC
  • mfrom: (39.1.3 merge-new-relations)
  • Revision ID: michael.nelson@canonical.com-20151027232718-26ewhz2bgb13m7pw
Merged lp:~evarlast/charms/trusty/elasticsearch/add-logs-relation
Merged lp:~canonical-is-sa/charms/trusty/elasticsearch/trunk
Updated so that peer-relation-joined will not fail, but -changed will , if the unit isn't part of the cluster.

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hooks/hooks.py
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import charmhelpers.contrib.ansible
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import charmhelpers.payload.execd
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import charmhelpers.core.host
 
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from charmhelpers.core import hookenv
 
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import os
 
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import shutil
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mountpoint = '/srv/elasticsearch'
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hooks = charmhelpers.contrib.ansible.AnsibleHooks(
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    playbook_path='playbook.yaml',
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    default_hooks=[
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        'config-changed',
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        'cluster-relation-joined',
 
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        'logs-relation-joined',
 
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        'data-relation-joined',
 
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        'data-relation-changed',
 
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        'data-relation-departed',
 
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        'data-relation-broken',
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        'peer-relation-joined',
 
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        'peer-relation-changed',
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        'peer-relation-departed',
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        'nrpe-external-master-relation-changed',
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        'rest-relation-joined',
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        '/usr/share/ansible')
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@hooks.hook('data-relation-joined', 'data-relation-changed')
 
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def data_relation():
 
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    if hookenv.relation_get('mountpoint') == mountpoint:
 
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        # Other side of relation is ready
 
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        migrate_to_mount(mountpoint)
 
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    else:
 
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        # Other side not ready yet, provide mountpoint
 
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        hookenv.log('Requesting storage for {}'.format(mountpoint))
 
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        hookenv.relation_set(mountpoint=mountpoint)
 
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@hooks.hook('data-relation-departed', 'data-relation-broken')
 
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def data_relation_gone():
 
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    hookenv.log('Data relation no longer present, stopping elasticsearch.')
 
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    charmhelpers.core.host.service_stop('elasticsearch')
 
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def migrate_to_mount(new_path):
 
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    """Invoked when new mountpoint appears. This function safely migrates
 
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    elasticsearch data from local disk to persistent storage (only if needed)
 
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    """
 
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    old_path = '/var/lib/elasticsearch'
 
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    if os.path.islink(old_path):
 
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        hookenv.log('{} is already a symlink, skipping migration'.format(
 
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            old_path))
 
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        return True
 
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    # Ensure our new mountpoint is empty. Otherwise error and allow
 
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    # users to investigate and migrate manually
 
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    files = os.listdir(new_path)
 
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    try:
 
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        files.remove('lost+found')
 
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    except ValueError:
 
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        pass
 
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    if files:
 
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        raise RuntimeError('Persistent storage contains old data. '
 
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                           'Please investigate and migrate data manually '
 
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                           'to: {}'.format(new_path))
 
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    os.chmod(new_path, 0700)
 
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    charmhelpers.core.host.service_stop('elasticsearch')
 
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    charmhelpers.core.host.rsync(os.path.join(old_path, ''),  # Ensure we have trailing slashes
 
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        os.path.join(new_path, ''),
 
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        options=['--archive'])
 
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    shutil.rmtree(old_path)
 
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    os.symlink(new_path, old_path)
 
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    charmhelpers.core.host.service_start('elasticsearch')
 
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if __name__ == "__main__":
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    hooks.execute(sys.argv)