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Viewing changes to hooks/charmhelpers/contrib/peerstorage/__init__.py

  • Committer: James Page
  • Date: 2014-04-16 08:20:08 UTC
  • mfrom: (52.2.30 keystone)
  • Revision ID: james.page@canonical.com-20140416082008-34w0nyak0y571tfp
[james-page,ivoks,hazmat,yolanda.robla,r=james-page,t=*]

Redux to used charm helpers
Support for Icehouse on 12.04 and 14.04
Support for Active/Active and SSL RabbitMQ
Support for SSL MySQL
Support for SSL endpoints
Support for PostgreSQL

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hooks/charmhelpers/contrib/peerstorage/__init__.py
 
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from charmhelpers.core.hookenv import (
 
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    relation_ids,
 
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    relation_get,
 
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    local_unit,
 
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    relation_set,
 
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)
 
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"""
 
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This helper provides functions to support use of a peer relation
 
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for basic key/value storage, with the added benefit that all storage
 
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can be replicated across peer units, so this is really useful for
 
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services that issue usernames/passwords to remote services.
 
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def shared_db_changed()
 
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    # Only the lead unit should create passwords
 
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    if not is_leader():
 
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        return
 
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    username = relation_get('username')
 
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    key = '{}.password'.format(username)
 
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    # Attempt to retrieve any existing password for this user
 
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    password = peer_retrieve(key)
 
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    if password is None:
 
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        # New user, create password and store
 
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        password = pwgen(length=64)
 
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        peer_store(key, password)
 
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    create_access(username, password)
 
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    relation_set(password=password)
 
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def cluster_changed()
 
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    # Echo any relation data other that *-address
 
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    # back onto the peer relation so all units have
 
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    # all *.password keys stored on their local relation
 
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    # for later retrieval.
 
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    peer_echo()
 
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"""
 
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def peer_retrieve(key, relation_name='cluster'):
 
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    """ Retrieve a named key from peer relation relation_name """
 
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    cluster_rels = relation_ids(relation_name)
 
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    if len(cluster_rels) > 0:
 
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        cluster_rid = cluster_rels[0]
 
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        return relation_get(attribute=key, rid=cluster_rid,
 
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                            unit=local_unit())
 
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    else:
 
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        raise ValueError('Unable to detect'
 
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                         'peer relation {}'.format(relation_name))
 
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def peer_store(key, value, relation_name='cluster'):
 
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    """ Store the key/value pair on the named peer relation relation_name """
 
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    cluster_rels = relation_ids(relation_name)
 
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    if len(cluster_rels) > 0:
 
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        cluster_rid = cluster_rels[0]
 
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        relation_set(relation_id=cluster_rid,
 
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                     relation_settings={key: value})
 
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    else:
 
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        raise ValueError('Unable to detect '
 
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                         'peer relation {}'.format(relation_name))
 
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def peer_echo(includes=None):
 
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    """Echo filtered attributes back onto the same relation for storage
 
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    Note that this helper must only be called within a peer relation
 
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    changed hook
 
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    """
 
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    rdata = relation_get()
 
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    echo_data = {}
 
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    if includes is None:
 
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        echo_data = rdata.copy()
 
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        for ex in ['private-address', 'public-address']:
 
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            if ex in echo_data:
 
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                echo_data.pop(ex)
 
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    else:
 
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        for attribute, value in rdata.iteritems():
 
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            for include in includes:
 
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                if include in attribute:
 
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                    echo_data[attribute] = value
 
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    if len(echo_data) > 0:
 
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        relation_set(relation_settings=echo_data)