Refactor worker logic.

Worker logic is now moved to a new controller class. Add initial
support for new 'hpcs_action' and 'hpcs_response' JSON elements.
Drivers now have the option of supporting SUSPEND, ENABLE, DELETE
and UPDATE actions.

libra/worker/controller.py

@@ -0,0 +1,156 @@
+# Copyright 2012 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from libra.common.faults import BadRequest
+
+
+class LBaaSController(object):
+
+    NODE_OK = "ENABLED"
+    NODE_ERR = "DISABLED"
+    RESPONSE_FAILURE = "FAIL"
+    RESPONSE_SUCCESS = "PASS"
+
+    def __init__(self, logger, driver, json_msg):
+        self.logger = logger
+        self.driver = driver
+        self.logger.debug("Entered LBaaSController")
+        # Standardize case on JSON elements
+        self.msg = dict((k.lower(), v) for k, v in json_msg.iteritems())
+
+    def run(self):
+        """
+        Process the JSON message and return a JSON response.
+        """
+
+        if 'hpcs_action' not in self.msg:
+            self.logger.error("Missing HPCS_ACTION value")
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+            return self.msg
+
+        action = self.msg['hpcs_action'].upper()
+        if action == 'CREATE':
+            return self._action_create()
+        elif action == 'UPDATE':
+            return self._action_update()
+        elif action == 'SUSPEND':
+            return self._action_suspend()
+        elif action == 'ENABLE':
+            return self._action_enable()
+        elif action == 'DELETE':
+            return self._action_delete()
+        else:
+            self.logger.error("Invalid HPCS_ACTION value: %s" % action)
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+            return self.msg
+
+    def _action_create(self):
+        """ Create a Load Balancer. """
+        if 'nodes' not in self.msg:
+            return BadRequest("Missing 'nodes' element").to_json()
+
+        for lb_node in self.msg['nodes']:
+            port, address = None, None
+
+            if 'port' in lb_node:
+                port = lb_node['port']
+            else:
+                return BadRequest("Missing 'port' element.").to_json()
+
+            if 'address' in lb_node:
+                address = lb_node['address']
+            else:
+                return BadRequest("Missing 'address' element.").to_json()
+
+            try:
+                self.driver.add_server(address, port)
+            except NotImplementedError:
+                self.logger.error(
+                    "Selected driver does not support adding a server."
+                )
+                lb_node['condition'] = self.NODE_ERR
+            except Exception as e:
+                self.logger.error("Failure trying adding server: %s, %s" %
+                                  (e.__class__, e))
+                lb_node['condition'] = self.NODE_ERR
+            else:
+                self.logger.debug("Added server: %s:%s" % (address, port))
+                lb_node['condition'] = self.NODE_OK
+
+        try:
+            self.driver.activate()
+        except NotImplementedError:
+            self.logger.error(
+                "Selected driver does not support activating changes."
+            )
+            for lb_node in self.msg['nodes']:
+                lb_node['condition'] = self.NODE_ERR
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+        except Exception as e:
+            self.logger.error("Failure activating changes: %s, %s" %
+                              (e.__class__, e))
+            for lb_node in self.msg['nodes']:
+                lb_node['condition'] = self.NODE_ERR
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+        else:
+            self.logger.info("Activated load balancer changes")
+            self.msg['hpcs_response'] = self.RESPONSE_SUCCESS
+
+        return self.msg
+
+    def _action_update(self):
+        """ Update a Load Balancer. """
+        # NOTE(shrews): We would need to know the current configuration of
+        # the load balancer to do an update. Note sure this is really feasible,
+        # so for now we just do the same as CREATE.
+        return self.action_create()
+
+    def _action_suspend(self):
+        """ Suspend a Load Balancer. """
+        try:
+            self.driver.suspend()
+        except NotImplementedError:
+            self.logger.error(
+                "Selected driver does not support SUSPEND action."
+            )
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+        else:
+            self.msg['hpcs_response'] = self.RESPONSE_SUCCESS
+        return self.msg
+
+    def _action_enable(self):
+        """ Enable a suspended Load Balancer. """
+        try:
+            self.driver.enable()
+        except NotImplementedError:
+            self.logger.error(
+                "Selected driver does not support ENABLE action."
+            )
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+        else:
+            self.msg['hpcs_response'] = self.RESPONSE_SUCCESS
+        return self.msg
+
+    def _action_delete(self):
+        """ Delete a Load Balancer. """
+        try:
+            self.driver.delete()
+        except NotImplementedError:
+            self.logger.error(
+                "Selected driver does not support DELETE action."
+            )
+            self.msg['hpcs_response'] = self.RESPONSE_FAILURE
+        else:
+            self.msg['hpcs_response'] = self.RESPONSE_SUCCESS
+        return self.msg