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