[WORKER] Return node status in STATS message

The message returned to the statsd daemon will now contain a
list of all nodes defined in the haproxy.cfg file and their status.
Status is currently as reported from HAProxy (UP/DOWN/no check/etc.)

Fields added to the returned JSON response:

 "nodes": [ { "id": "1234", "status": "UP" } ]

The 'id' part of the JSON response will contain either the unique
ID of the node (as defined during the UPDATE message), or "serverN"
for older configs that haven't been updated to use the node ID.

Change-Id: I794b4901f542d922ebccd9ece9d86236584d4b46

libra/common/lbstats.py

@@ -22,6 +22,7 @@ class LBStatistics(object):
         self.stats = {}
         self.bytes_out = 0L
         self.bytes_in = 0L
+        self.nodes = dict()
         self.utc_timestamp = datetime.datetime.utcnow()
 
     @property
@@ -54,3 +55,10 @@ class LBStatistics(object):
         if not isinstance(value, datetime.datetime):
             raise TypeError("Must be a datetime.datetime: '%s'" % value)
         self._utc_ts = value
+
+    def add_node_status(self, node, status):
+        self.nodes[node] = status
+
+    def node_status_map(self):
+        """ Return a dictionary, indexed by node ID, of the node status """
+        return self.nodes

libra/worker/controller.py

@@ -50,7 +50,6 @@ class LBaaSController(object):
             return self.msg
 
         action = self.msg[self.ACTION_FIELD].upper()
-        self.logger.info("Requested action: %s" % action)
 
         try:
             if action == 'UPDATE':
@@ -353,7 +352,7 @@ class LBaaSController(object):
 
         try:
             # TODO: Do something with the returned statistics
-            self.driver.get_stats(protocol=None)
+            stats = self.driver.get_stats()
         except NotImplementedError:
             error = "Selected driver does not support STATS action."
             self.logger.error(error)
@@ -368,5 +367,11 @@ class LBaaSController(object):
             self.msg[self.RESPONSE_FIELD] = self.RESPONSE_FAILURE
             self.msg[self.ERROR_FIELD] = str(e)
         else:
+            node_status = stats.node_status_map()
+            self.msg['nodes'] = []
+            for node in node_status.keys():
+                self.msg['nodes'].append({'id': node,
+                                          'status': node_status[node]})
             self.msg[self.RESPONSE_FIELD] = self.RESPONSE_SUCCESS
+
         return self.msg

libra/worker/drivers/haproxy/driver.py

@@ -278,7 +278,7 @@ class HAProxyDriver(LoadBalancerDriver):
         # restart, otherwise the log file will be kept open and not reappear.
         self.ossvc.syslog_restart()
 
-    def get_stats(self, protocol):
+    def get_stats(self, protocol=None):
         return self.ossvc.get_stats(protocol)
 
     def archive(self, method, params):

libra/worker/drivers/haproxy/query.py

@@ -71,21 +71,30 @@ class HAProxyQuery(object):
         list_results = results.split('\n')
         return list_results
 
-    def get_server_status(self, protocol):
+    def get_server_status(self, protocol=None):
         """
         Get status for each server for a protocol backend.
         Return a list of tuples containing server name and status.
         """
 
+        if protocol:
             filter_string = protocol.lower() + "-servers"
+
         results = self.show_stat(object_type=4)  # servers only
 
         final_results = []
         for line in results[1:]:
             elements = line.split(',')
-            if elements[0] != filter_string:
+            if protocol and elements[0] != filter_string:
                 next
             else:
                 # 1 - server name, 17 - status
-                final_results.append((elements[1], elements[17]))
+                # Here we look for the new server name form of "id-NNNN"
+                # where NNNN is the unique node ID. The old form could
+                # be "serverX", in which case we leave it alone.
+                if elements[1][0:3] == "id-":
+                    junk, node_id = elements[1].split('-')
+                else:
+                    node_id = elements[1]
+                final_results.append((node_id, elements[17]))
         return final_results

libra/worker/drivers/haproxy/ubuntu_services.py

@@ -130,7 +130,7 @@ class UbuntuServices(ServicesBase):
         self.sudo_rm(self._config_file)
         self.sudo_rm(self._backup_config)
 
-    def get_stats(self, protocol):
+    def get_stats(self, protocol=None):
         """
         Query HAProxy socket for stats on the given protocol.
 
@@ -155,8 +155,8 @@ class UbuntuServices(ServicesBase):
         stats = LBStatistics()
         query = HAProxyQuery('/var/run/haproxy-stats.socket')
 
-        # TODO: Do something with the returned results. For now, we are
-        # basically just treating this as a 'ping' to the process.
-        query.show_info()
+        node_status_list = query.get_server_status(protocol)
+        for node, status in node_status_list:
+            stats.add_node_status(node, status)
 
         return stats