Initial architecture changes for using dynamic drivers and for a HAProxy driver.

libra/worker/drivers/__init__.py

@@ -0,0 +1,13 @@
+# 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.

libra/worker/drivers/base.py

@@ -0,0 +1,37 @@
+# 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
+
+
+class LoadBalancerDriver(object):
+    """
+    Load balancer device driver base class.
+
+    This defines the API for interacting with various load balancing
+    appliances. Drivers for these appliances should inherit from this
+    class and implement the relevant API methods that it can support.
+
+    Generally, an appliance driver should queue up any changes made
+    via these API calls until the activate() method is called.
+    """
+
+    def bind(self, address, port):
+        """ Set proxy listening interface and port. """
+        raise NotImplementedError()
+
+    def add_server(self, host, port):
+        """ Add a server for which we will proxy. """
+        raise NotImplementedError()
+
+    def activate(self):
+        """ Activate any changes made. """
+        raise NotImplementedError()

libra/worker/drivers/haproxy/__init__.py

@@ -0,0 +1,13 @@
+# 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.

libra/worker/drivers/haproxy/driver.py

@@ -0,0 +1,44 @@
+# 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.worker.drivers.base import LoadBalancerDriver
+
+
+class HAProxyDriver(LoadBalancerDriver):
+
+    def __init__(self):
+        self._config_file = '/etc/haproxy/haproxy.cfg'
+        self._servers = []
+        self.bind('0.0.0.0', 80)
+
+    def _write_config(self):
+        pass
+
+    def _restart(self):
+        pass
+
+    ####################
+    # Driver API Methods
+    ####################
+
+    def bind(self, address, port):
+        self._bind_address = address
+        self._bind_port = port
+
+    def add_server(self, host, port):
+        self._servers.append((host, port))
+
+    def activate(self):
+        self._write_config()
+        self._restart()

libra/worker/worker.py

@@ -16,7 +16,6 @@ import daemon
 import gearman.errors
 import json
 import lockfile
-import logging
 import socket
 from time import sleep
 
@@ -28,17 +27,23 @@ from libra.common.options import Options, setup_logging
 def lbaas_task(worker, job):
     """ Main Gearman worker task.  """
 
+    NODE_OK = "ENABLED"
+    NODE_ERR = "DISABLED"
+
+    logger = worker.logger
+    driver = worker.driver
+
     # Turn string into JSON object
     data = json.loads(job.data)
 
     lb_name = data['name']
-    logging.info("LB name: %s" % lb_name)
+    logger.debug("LB name: %s" % lb_name)
 
     if 'nodes' not in data:
         return BadRequest("Missing 'nodes' element").to_json()
 
     for lb_node in data['nodes']:
-        port, address, status = None, None, None
+        port, address = None, None
 
         if 'port' in lb_node:
             port = lb_node['port']
@@ -50,24 +55,45 @@ def lbaas_task(worker, job):
         else:
             return BadRequest("Missing 'address' element.").to_json()
 
-        if 'status' in lb_node:
-            status = lb_node['status']
+        logger.debug("Server node: %s:%s" % (address, port))
 
-        logging.info("LB node: %s:%s - %s" % (address, port, status))
-        lb_node['status'] = 'ACTIVE'
+        try:
+            driver.add_server(address, port)
+        except NotImplementedError:
+            logger.info("Selected driver could not add server.")
+            lb_node['condition'] = NODE_ERR
+        except Exception as e:
+            logger.critical("Failure trying adding server: %s, %s" %
+                            (e.__class__, e))
+            lb_node['condition'] = NODE_ERR
+        else:
+            lb_node['condition'] = NODE_OK
 
-    # Return the same JSON object, but with status fields set.
+    try:
+        driver.activate()
+    except NotImplementedError:
+        logger.info("Selected driver could not activate changes.")
+        for lb_node in data['nodes']:
+            lb_node['condition'] = NODE_ERR
+
+    # Return the same JSON object, but with condition fields set.
     return data
 
 
+class CustomJSONGearmanWorker(JSONGearmanWorker):
+    logger = None
+    driver = None
+
+
 class Server(object):
     """
     Encapsulates server activity so we can run it in either daemon or
     non-daemon mode.
     """
 
-    def __init__(self, logger, servers, reconnect_sleep):
-        self.logger = logger
+    def __init__(self, servers, reconnect_sleep):
+        self.logger = None
+        self.driver = None
         self.servers = servers
         self.reconnect_sleep = reconnect_sleep
 
@@ -76,7 +102,7 @@ class Server(object):
         task_name = "lbaas-%s" % my_ip
         self.logger.debug("Registering task %s" % task_name)
 
-        worker = JSONGearmanWorker(self.servers)
+        worker = CustomJSONGearmanWorker(self.servers)
         worker.set_client_id(my_ip)
         worker.register_task(task_name, lbaas_task)
 
@@ -103,13 +129,22 @@ def main():
 
     options = Options('worker', 'Worker Daemon')
     options.parser.add_argument(
-        '-s', dest='reconnect_sleep', type=int, metavar="TIME",
+        '-s', dest='reconnect_sleep', type=int, metavar='TIME',
         default=60, help='seconds to sleep between job server reconnects'
     )
+    options.parser.add_argument(
+        '--driver', dest='driver', default='haproxy.driver.HAProxyDriver',
+        help='Class name of device driver to use'
+    )
     args = options.run()
 
     logger = setup_logging('libra_worker', args)
-    server = Server(logger, ['localhost:4730'], args.reconnect_sleep)
+    from libra.worker.drivers.haproxy.driver import HAProxyDriver
+    driver = HAProxyDriver()
+
+    server = Server(['localhost:4730'], args.reconnect_sleep)
+    server.logger = logger
+    server.driver = driver
 
     if args.nodaemon:
         server.main()

tests/test_lbaas_worker.py

@@ -1,6 +1,13 @@
 import json
+import logging
 import unittest
+import mock
 from libra.worker.worker import lbaas_task
+from libra.worker.drivers.base import LoadBalancerDriver
+
+
+class FakeDriver(LoadBalancerDriver):
+    pass
 
 
 class FakeJob(object):
@@ -11,6 +18,12 @@ class FakeJob(object):
         self.data = json.dumps(data)
 
 
+class FakeWorker(object):
+    def __init__(self):
+        self.logger = logging.getLogger('lbaas_worker_test')
+        self.driver = FakeDriver()
+
+
 class TestLBaaSTask(unittest.TestCase):
     def setUp(self):
         pass
@@ -21,7 +34,7 @@ class TestLBaaSTask(unittest.TestCase):
     def testLBaaSTask(self):
         """ Test the lbaas_task() function """
 
-        worker = None
+        worker = FakeWorker()
         data = {
             "name": "a-new-loadbalancer",
             "nodes": [
@@ -43,15 +56,15 @@ class TestLBaaSTask(unittest.TestCase):
         self.assertEqual(len(r["nodes"]), 2)
         self.assertEqual(r["nodes"][0]["address"], data["nodes"][0]["address"])
         self.assertEqual(r["nodes"][0]["port"], data["nodes"][0]["port"])
-        self.assertIn("status", r["nodes"][0])
+        self.assertIn("condition", r["nodes"][0])
         self.assertEqual(r["nodes"][1]["address"], data["nodes"][1]["address"])
         self.assertEqual(r["nodes"][1]["port"], data["nodes"][1]["port"])
-        self.assertIn("status", r["nodes"][1])
+        self.assertIn("condition", r["nodes"][1])
 
     def testMissingNodes(self):
         """ Test invalid messages: missing nodes """
 
-        worker = None
+        worker = FakeWorker()
         data = {
             "name": "a-new-loadbalancer"
         }
@@ -63,7 +76,7 @@ class TestLBaaSTask(unittest.TestCase):
     def testMissingPort(self):
         """ Test invalid messages: missing port """
 
-        worker = None
+        worker = FakeWorker()
         data = {
             "name": "a-new-loadbalancer",
             "nodes": [
@@ -80,7 +93,7 @@ class TestLBaaSTask(unittest.TestCase):
     def testMissingAddress(self):
         """ Test invalid messages: missing address """
 
-        worker = None
+        worker = FakeWorker()
         data = {
             "name": "a-new-loadbalancer",
             "nodes": [