def send_flip_request(self, remote_gateway, connection):
'''
Sends a message to the remote gateway via redis pubsub channel. This is called from the
watcher thread, when a flip rule gets activated.
- redis channel name: rocon:<remote_gateway_name>
- data : list of [ command, gateway, rule type, type, xmlrpc_uri ]
- [0] - command : in this case 'flip'
- [1] - gateway : the name of this gateway, i.e. the flipper
- [2] - name : local name
- [3] - node : local node name
- [4] - connection_type : one of ConnectionType.PUBLISHER etc
- [5] - type_info : a ros format type (e.g. std_msgs/String or service api)
- [6] - xmlrpc_uri : the xmlrpc node uri
@param command : string command name - either 'flip' or 'unflip'
@type str
@param flip_rule : the flip to send
@type gateway_msgs.RemoteRule
@param type_info : topic type (e.g. std_msgs/String)
@param str
@param xmlrpc_uri : the node uri
@param str
'''
source = hub_api.key_base_name(self._redis_keys['gateway'])
cmd = utils.serialize_connection_request('flip', source, connection)
try:
self._redis_server.publish(
hub_api.create_rocon_key(remote_gateway), cmd)
except Exception as unused_e:
return False
return True
def run(self):
'''
Run the hub watcher (sidekick) thread at the rate specified by the
watcher_thread_rate parameter. The watcher thread does the following:
1. For all gateways available, see if we have a pinger available.
2. Add and remove pingers as necessary
3. Depending on pinger stats, update hub appropriately
'''
rate = WallRate(self.watcher_thread_rate)
unavailable_set = set()
while True:
remote_gateway_names = self.hub.list_remote_gateway_names()
# Check all pingers
for name in remote_gateway_names:
gateway_key = hub_api.create_rocon_key(name)
# Get time for this gateway when hub was last seen
ping_key = hub_api.create_rocon_gateway_key(name, ':ping')
expiration_time = self.hub._redis_server.ttl(ping_key)
# rospy.logwarn("<= {0} TTL {1}".format(ping_key, expiration_time))
if expiration_time is None or expiration_time == -2:
# Probably in the process of starting up, ignore for now
continue
seconds_since_last_seen = int(ConnectionStatistics.MAX_TTL -
expiration_time)
# rospy.logwarn("<= Not seen since {0} secs...".format(seconds_since_last_seen))
# if it has been gone for more than one loop
if seconds_since_last_seen > rate.period:
rospy.logwarn("Hub Watcher: gateway " + name +
" has been unavailable for " +
str(seconds_since_last_seen) + " seconds.")
unavailable_set.add(gateway_key)
self.hub.mark_named_gateway_available(
gateway_key, False, seconds_since_last_seen)
# Check if gateway gone
if seconds_since_last_seen > self.gateway_gone_timeout:
rospy.logwarn("Hub Watcher: gateway " + name +
" has been unavailable for " +
str(self.gateway_gone_timeout) +
" seconds! Removing from hub.")
# Gone for too long => unregister
self.hub.unregister_named_gateway(gateway_key)
# Mark gateway as available
else:
if gateway_key in unavailable_set:
rospy.logwarn("Hub Watcher: gateway " + name +
" detected available again !")
unavailable_set.remove(gateway_key)
self.hub.mark_named_gateway_available(
gateway_key, True, seconds_since_last_seen)
rate.sleep()
def _send_unflip_request(self, remote_gateway, rule):
source = hub_api.key_base_name(self._redis_keys['gateway'])
cmd = utils.serialize_rule_request('unflip', source, rule)
try:
self._redis_server.publish(
hub_api.create_rocon_key(remote_gateway), cmd)
except Exception as unused_e:
return False
return True
def register_gateway(self, firewall, unique_gateway_name, hub_connection_lost_gateway_hook, gateway_ip):
'''
Register a gateway with the hub.
@param firewall
@param unique_gateway_name
@param hub_connection_lost_gateway_hook : used to trigger Gateway.disengage_hub(hub)
on lost hub connections in redis pubsub listener thread.
@gateway_ip
@raise HubConnectionLostError if for some reason, the redis server has become unavailable.
'''
if not self._redis_server:
raise HubConnectionLostError()
self._unique_gateway_name = unique_gateway_name
self._redis_keys['gateway'] = hub_api.create_rocon_key(unique_gateway_name)
self._redis_keys['firewall'] = hub_api.create_rocon_gateway_key(unique_gateway_name, 'firewall')
self._firewall = 1 if firewall else 0
self._hub_connection_lost_gateway_hook = hub_connection_lost_gateway_hook
if not self._redis_server.sadd(self._redis_keys['gatewaylist'], self._redis_keys['gateway']):
# should never get here - unique should be unique
pass
self.mark_named_gateway_available(self._redis_keys['gateway'])
self._redis_server.set(self._redis_keys['firewall'], self._firewall)
# I think we just used this for debugging, but we might want to hide it in
# future (it's the ros master hostname/ip)
self._redis_keys['ip'] = hub_api.create_rocon_gateway_key(unique_gateway_name, 'ip')
self._redis_server.set(self._redis_keys['ip'], gateway_ip)
self.private_key, public_key = utils.generate_private_public_key()
self._redis_keys['public_key'] = hub_api.create_rocon_gateway_key(unique_gateway_name, 'public_key')
old_key = self._redis_server.get(self._redis_keys['public_key'])
serialized_public_key = utils.serialize_key(public_key)
self._redis_server.set(self._redis_keys['public_key'], serialized_public_key)
if serialized_public_key != old_key:
rospy.loginfo('Gateway : Found existing mismatched public key on the hub. ' +
'Requesting resend for all flip-ins.')
self._resend_all_flip_ins()
# Mark this gateway as now available
self._redis_server.sadd(self._redis_keys['gatewaylist'], self._redis_keys['gateway'])
self.hub_connection_checker_thread = HubConnectionCheckerThread(
self.ip, self.port, self._hub_connection_lost_hook)
self.hub_connection_checker_thread.start()
self.connection_lost_lock = threading.Lock()
# Let hub know we are alive
ping_key = hub_api.create_rocon_gateway_key(self._unique_gateway_name, ':ping')
self._redis_server.set(ping_key, True)
self._redis_server.expire(ping_key, gateway_msgs.ConnectionStatistics.MAX_TTL)
def run(self):
'''
Run the hub watcher (sidekick) thread at the rate specified by the
watcher_thread_rate parameter. The wathcer thread does the following:
1. For all gateways available, see if we have a pinger available.
2. Add and remove pingers as necessary
3. Depending on pinger stats, update hub appropriately
'''
rate = WallRate(self.watcher_thread_rate)
while True:
remote_gateway_names = self.hub.list_remote_gateway_names()
# Check all pingers
for name in remote_gateway_names:
gateway_key = hub_api.create_rocon_key(name)
# Get time for this gateway when hub was last seen
ping_key = hub_api.create_rocon_gateway_key(name, ':ping')
expiration_time = self.hub._redis_server.ttl(ping_key)
if expiration_time is None:
# Probably in the process of starting up, ignore for now
continue
seconds_since_last_seen = \
int(ConnectionStatistics.MAX_TTL - expiration_time)
# Check if gateway gone for low timeout (unavailable)
if seconds_since_last_seen > self.gateway_unavailable_timeout:
if name not in self.unavailable_gateways:
rospy.logwarn("Hub Watcher: gateway " + name +
" has been unavailable for " +
str(self.gateway_unavailable_timeout) +
" seconds! Marking as unavailable.")
self.unavailable_gateways.append(name)
self.hub.mark_named_gateway_available(gateway_key, False,
seconds_since_last_seen)
else:
if name in self.unavailable_gateways:
self.unavailable_gateways.remove(name)
self.hub.mark_named_gateway_available(gateway_key, True,
seconds_since_last_seen)
# Check if gateway gone for high timeout (dead)
if seconds_since_last_seen > self.gateway_dead_timeout:
rospy.logwarn("Hub Watcher: gateway " + name +
" has been unavailable for " +
str(self.gateway_dead_timeout) +
" seconds! Removing from hub.")
self.hub.unregister_named_gateway(gateway_key)
rate.sleep()
def register_gateway(self, firewall, unique_gateway_name,
remote_gateway_request_callbacks,
hub_connection_lost_gateway_hook, gateway_ip):
'''
Register a gateway with the hub.
@param firewall
@param unique_gateway_name
@param remote_gateway_request_callbacks
@param hub_connection_lost_hook : used to trigger Gateway.disengage_hub(hub) on lost hub connections in redis pubsub listener thread.
@gateway_ip
@raise HubConnectionLostError if for some reason, the redis server has become unavailable.
'''
if not self._redis_server:
raise HubConnectionLostError()
self._unique_gateway_name = unique_gateway_name
self._redis_keys['gateway'] = hub_api.create_rocon_key(
unique_gateway_name)
self._redis_keys['firewall'] = hub_api.create_rocon_gateway_key(
unique_gateway_name, 'firewall')
self._firewall = 1 if firewall else 0
self._redis_keys['gatewaylist'] = hub_api.create_rocon_hub_key(
'gatewaylist')
self._remote_gateway_request_callbacks = remote_gateway_request_callbacks
self._hub_connection_lost_gateway_hook = hub_connection_lost_gateway_hook
if not self._redis_server.sadd(self._redis_keys['gatewaylist'],
self._redis_keys['gateway']):
# should never get here - unique should be unique
pass
unused_ret = self._redis_server.sadd(self._redis_keys['gatewaylist'],
self._redis_keys['gateway'])
self._redis_server.set(self._redis_keys['firewall'], self._firewall)
# I think we just used this for debugging, but we might want to hide it in future (it's the ros master hostname/ip)
self._redis_keys['ip'] = hub_api.create_rocon_gateway_key(
unique_gateway_name, 'ip')
self._redis_server.set(self._redis_keys['ip'], gateway_ip)
self._redis_channels['gateway'] = self._redis_keys['gateway']
self._redis_pubsub_server.subscribe(self._redis_channels['gateway'])
self.remote_gateway_listener_thread = RedisListenerThread(
self._redis_pubsub_server, self._remote_gateway_request_callbacks,
self._hub_connection_lost_hook)
self.remote_gateway_listener_thread.start()
