Source code for requires
#!/usr/bin/python
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from charmhelpers.core.reactive import RelationBase
from charmhelpers.core.reactive import hook
from charmhelpers.core.reactive import scopes
[docs]class PostgreSQLClient(RelationBase):
# We only expect a single pgsql server to be related. Additionally, if
# there are multiple units, it would be for replication purposes only,
# so we would expect a leader to provide our connection info, or at least
# for all pgsql units to agree on the connection info. Thus, we use a
# global conversation scope in which all services and units share the
# same conversation.
scope = scopes.GLOBAL
# These remote data fields will be automatically mapped to accessors
# with a basic documentation string provided.
auto_accessors = ['host', 'port', 'database', 'user', 'password',
'schema_user', 'schema_password']
@hook('{requires:pgsql}-relation-{joined,changed}')
def changed(self):
self.set_state('{relation_name}.connected')
if self.connection_string():
self.set_state('{relation_name}.database.available')
@hook('{requires:pgsql}-relation-{broken,departed}')
def departed(self):
self.remove_state('{relation_name}.connected')
self.remove_state('{relation_name}.database.available')
[docs] def request_roles(self, *roles):
"""
Tell the PostgreSQL server to provide our user with a certain set of roles.
:param list roles: One or more role names to give to this service's user.
"""
self.set_remote('roles', ','.join(roles))
[docs] def change_database_name(self, dbname):
"""
Tell the PostgreSQL server to provide us with a database with a specific name.
:param str dbname: New name for the database to use.
"""
self.set_remote('database', dbname)
[docs] def connection_string(self):
"""
Get the connection string, if available, or None.
"""
data = {
'host': self.host(),
'port': self.port(),
'database': self.database(),
'user': self.user(),
'password': self.password(),
}
if all(data.values()):
return str.format(
'host={host} port={port} dbname={database} user={user} password={password}',
**data)
return None