charm/openvim/interface-openvim/requires.py

   1 ##
   2 # Copyright 2016
   3 # This file is part of openvim
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   6 # not use this file except in compliance with the License. You may obtain
   7 # a copy of the License at
   8 #
   9 #         http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  13 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  14 # License for the specific language governing permissions and limitations
  15 # under the License.
  16 #
  17 ##
  18
  19 from charms.reactive import hook
  20 from charms.reactive import RelationBase
  21 from charms.reactive import scopes
  22
  23
  24 class OpenVimRequires(RelationBase):
  25     scope = scopes.UNIT
  26
  27     @hook('{requires:openvim}-relation-{joined,changed}')
  28     def changed(self):
  29         conv = self.conversation()
  30         if conv.get_remote('port'):
  31             # this unit's conversation has a port, so
  32             # it is part of the set of available units
  33             conv.set_state('{relation_name}.available')
  34
  35     @hook('{requires:openvim}-relation-{departed,broken}')
  36     def broken(self):
  37         conv = self.conversation()
  38         conv.remove_state('{relation_name}.available')
  39
  40     def services(self):
  41         """
  42         Returns a list of available openvim services and their associated hosts
  43         and ports.
  44
  45         The return value is a list of dicts of the following form::
  46
  47             [
  48                 {
  49                     'service_name': name_of_service,
  50                     'hosts': [
  51                         {
  52                             'hostname': address_of_host,
  53                             'port': port_for_host,
  54                             'user': user_for_host,
  55                         },
  56                         # ...
  57                     ],
  58                 },
  59                 # ...
  60             ]
  61         """
  62         services = {}
  63         for conv in self.conversations():
  64             service_name = conv.scope.split('/')[0]
  65             service = services.setdefault(service_name, {
  66                 'service_name': service_name,
  67                 'hosts': [],
  68             })
  69             host = conv.get_remote('hostname') or \
  70                 conv.get_remote('private-address')
  71             port = conv.get_remote('port')
  72             user = conv.get_remote('user')
  73             if host and port:
  74                 service['hosts'].append({
  75                     'hostname': host,
  76                     'port': port,
  77                     'user': user,
  78                 })
  79         return [s for s in services.values() if s['hosts']]