[WORKER] Support LB timeout options

Parse the new loadBalancers.options section of the UPDATE JSON
message to set various timeouts and retry values. These options
can be set per-protocol. Timeout values are assumed to be in
milliseconds, with the default being 30000 ms for the timeouts
and 3 for the retry value.

Example JSON message:

{
  "hpcs_action": "UPDATE",
  "loadBalancers": [
     "protocol": "http",
     "options": {
         "client_timeout": "30000",
         "server_timeout": "30000",
         "connect_timeout": "30000",
         "connect_retries": "3"
     },
     ...
  ]
}

Change-Id: I45a6b9c85e8fc282ac80fa3f0eae0193e08e9756

libra/worker/controller.py

@@ -133,6 +133,45 @@ class LBaaSController(object):
             )
             raise
 
+    def _set_lb_options(self, protocol, options):
+        """
+        Parse load balancer options.
+
+        options
+            Dictionary of load balancer options.
+
+        Returns: True on success, False otherwise
+        """
+
+        # Default timeout values in milliseconds
+        client_val = 30000
+        server_val = 30000
+        connect_val = 30000
+        retries_val = 3
+
+        if 'client_timeout' in options:
+            client_val = options['client_timeout']
+        if 'server_timeout' in options:
+            server_val = options['server_timeout']
+        if 'connect_timeout' in options:
+            connect_val = options['connect_timeout']
+        if 'connect_retries' in options:
+            retries_val = options['connect_retries']
+
+        try:
+            self.driver.set_timeouts(protocol, client_val, server_val,
+                                     connect_val, retries_val)
+        except NotImplementedError:
+            pass
+        except Exception as e:
+            error = "Failed to set timeout values: %s" % e
+            LOG.error(error)
+            self.msg[self.ERROR_FIELD] = error
+            self.msg[self.RESPONSE_FIELD] = self.RESPONSE_FAILURE
+            return False
+
+        return True
+
     def _action_discover(self):
         """
         Return service discovery information.
@@ -257,6 +296,15 @@ class LBaaSController(object):
                     self.msg[self.RESPONSE_FIELD] = self.RESPONSE_FAILURE
                     return self.msg
 
+            if 'options' in current_lb:
+                lb_options = current_lb['options']
+            else:
+                lb_options = {}
+
+            # Always call _set_lb_options() since it sets sensible defaults
+            if not self._set_lb_options(current_lb['protocol'], lb_options):
+                return self.msg
+
             for lb_node in current_lb['nodes']:
                 port = None
                 address = None

libra/worker/drivers/base.py

@@ -122,3 +122,10 @@ class LoadBalancerDriver(object):
     def archive(self, method, params):
         """ Archive the load balancer logs using the specified method. """
         raise NotImplementedError()
+
+    def set_timeouts(self, protocol, client_timeout, server_timeout,
+                     connect_timeout, connect_retries):
+        """
+        Set the various timeout values for the specified protocol.
+        """
+        raise NotImplementedError()

libra/worker/drivers/haproxy/driver.py

@@ -75,10 +75,6 @@ class HAProxyDriver(LoadBalancerDriver):
         output.append('    option dontlognull')
         output.append('    option redispatch')
         output.append('    maxconn 50000')
-        output.append('    retries 3')
-        output.append('    timeout connect 30000ms')
-        output.append('    timeout client 30000ms')
-        output.append('    timeout server 30000ms')
 
         for proto in self._config:
             protocfg = self._config[proto]
@@ -93,6 +89,8 @@ class HAProxyDriver(LoadBalancerDriver):
             output.append('    mode %s' % real_proto)
             output.append('    bind %s:%s' % (protocfg['bind_address'],
                                               protocfg['bind_port']))
+            output.append('    timeout client %sms' %
+                          protocfg['timeouts']['timeout_client'])
             output.append('    default_backend %s-servers' % real_proto)
 
             # HTTP specific options for the frontend
@@ -109,6 +107,11 @@ class HAProxyDriver(LoadBalancerDriver):
             output.append('backend %s-servers' % real_proto)
             output.append('    mode %s' % real_proto)
             output.append('    balance %s' % protocfg['algorithm'])
+            output.append('    timeout connect %sms' %
+                          protocfg['timeouts']['timeout_connect'])
+            output.append('    timeout server %sms' %
+                          protocfg['timeouts']['timeout_server'])
+            output.append('    retries %s' % protocfg['timeouts']['retries'])
 
             # default healthcheck if none specified
             monitor = 'check inter 30s'
@@ -420,3 +423,13 @@ class HAProxyDriver(LoadBalancerDriver):
         else:
             raise Exception("Driver does not support archive method '%s'" %
                             method)
+
+    def set_timeouts(self, protocol, client_timeout, server_timeout,
+                     connect_timeout, connect_retries):
+        protocol = protocol.lower()
+        self._config[protocol]['timeouts'] = {
+            'timeout_client': client_timeout,
+            'timeout_server': server_timeout,
+            'timeout_connect': connect_timeout,
+            'retries': connect_retries
+        }