charm/openvim/interface-openvim/requires.py

   1 from charms.reactive import hook
   2 from charms.reactive import RelationBase
   3 from charms.reactive import scopes
   4
   5
   6 class OpenVimRequires(RelationBase):
   7     scope = scopes.UNIT
   8
   9     @hook('{requires:openvim}-relation-{joined,changed}')
  10     def changed(self):
  11         conv = self.conversation()
  12         if conv.get_remote('port'):
  13             # this unit's conversation has a port, so
  14             # it is part of the set of available units
  15             conv.set_state('{relation_name}.available')
  16
  17     @hook('{requires:openvim}-relation-{departed,broken}')
  18     def broken(self):
  19         conv = self.conversation()
  20         conv.remove_state('{relation_name}.available')
  21
  22     def services(self):
  23         """
  24         Returns a list of available openvim services and their associated hosts
  25         and ports.
  26
  27         The return value is a list of dicts of the following form::
  28
  29             [
  30                 {
  31                     'service_name': name_of_service,
  32                     'hosts': [
  33                         {
  34                             'hostname': address_of_host,
  35                             'port': port_for_host,
  36                             'user': user_for_host,
  37                         },
  38                         # ...
  39                     ],
  40                 },
  41                 # ...
  42             ]
  43         """
  44         services = {}
  45         for conv in self.conversations():
  46             service_name = conv.scope.split('/')[0]
  47             service = services.setdefault(service_name, {
  48                 'service_name': service_name,
  49                 'hosts': [],
  50             })
  51             host = conv.get_remote('hostname') or \
  52                 conv.get_remote('private-address')
  53             port = conv.get_remote('port')
  54             user = conv.get_remote('user')
  55             if host and port:
  56                 service['hosts'].append({
  57                     'hostname': host,
  58                     'port': port,
  59                     'user': user,
  60                 })
  61         return [s for s in services.values() if s['hosts']]