class Controller(BaseController):
def __init__(self, unit=None):
self.unit = unit or Unit()
self._elb = None
self._ec2 = None
self._config = None
state_path = os.path.join(os.environ.get("CHARM_DIR", ""), "elb.state")
self._state = KVFile(state_path)
def get_zones(self):
"""
Get all the zones currently in use by backend instances
"""
zones = []
for k, v in self._state.get_all().items():
zones.append(v['zone'])
return zones
def get_elb(self):
"""
Get the charm elb abstraction.
"""
if self._elb:
return self._elb
data = self.get_config()
self._elb = ELB(
data['access-key-id'],
data['secret-access-key'],
self.get_region(),
self.unit.get_service_identifier())
return self._elb
def get_instance(self):
"""
Get the remote instance id and zone the hook is currently
executing for.
Also saves the information for future use.
"""
data = self.unit.relation_get()
port = data.get('port')
address = data.get('hostname')
if not port or not address:
self.unit.log('Peer address not set, waiting for handshake')
raise RetryLater()
ec2 = self.get_ec2()
instance = self.unit.get_instance(ec2)
return instance.id, instance.placement
def on_changed(self):
"""Called when a unit changes it settings or comes online.
"""
lb = self.get_elb()
instance_id, zone = self.get_instance()
if instance_id is None:
return
if lb.exists():
print "added %s to elb %s" % (instance_id, lb.elb_name)
lb.add(instance_id, zone)
else:
print "creating elb %s" % (lb.elb_name)
lb.create([zone])
lb.add(instance_id, zone)
def on_depart(self):
"""Called when a unit is no longer available.
"""
data = self._state.get(self.unit.remote_unit)
if data is None:
print "could not find remote unit %s" % self.unit.remote_unit
return
instance_id = data['instance-id']
lb = self.get_elb()
if lb.exists():
print "removed %s from elb %s" % (instance_id, lb.elb_name)
lb.remove(instance_id)
self._state.remove(self.unit.remote_unit)
lb.sync(self.get_zones())
def on_broken(self):
"""Called when the relationship is broken.
"""
lb = self.get_elb()
if lb.exists():
print "removed elb %s" % (lb.elb_name)
lb.destroy()
def on_config_changed(self):
lb = self.get_elb()
print lb
