From 7926137bb5861a756937930d8243d9d2465017d2 Mon Sep 17 00:00:00 2001
From: Lisa Zangrando <lisa.zangrando@pd.infn.it>
Date: Fri, 20 Jan 2017 10:45:56 +0100
Subject: [PATCH] Add support for AMQP HA to NovaManager

- AMQP HA cluster support added
- added the new 'amqp_hosts' configuration attribute

Change-Id: I20973b3a66540814b86970628270dc83adab8018
Sem-Ver: feature
---
 synergy_scheduler_manager/nova_manager.py | 64 ++++++++++++++++++-----
 1 file changed, 51 insertions(+), 13 deletions(-)

diff --git a/synergy_scheduler_manager/nova_manager.py b/synergy_scheduler_manager/nova_manager.py
index c06e64b..58bdee8 100644
--- a/synergy_scheduler_manager/nova_manager.py
+++ b/synergy_scheduler_manager/nova_manager.py
@@ -53,11 +53,48 @@ CONFIG = ConfigParser.SafeConfigParser()
 
 class MessagingAPI(object):
 
-    def __init__(self, transport_url):
-        LOG.debug("setting up the AMQP transport url: %s" % transport_url)
+    def __init__(self, amqp_backend, amqp_user,
+                 amqp_password, amqp_hosts, amqp_virt_host):
         oslo_msg.set_transport_defaults(control_exchange="nova")
+
+        transport_hosts = self._createTransportHosts(amqp_user,
+                                                     amqp_password,
+                                                     amqp_hosts)
+
+        transport_url = oslo_msg.TransportURL(CONF,
+                                              transport=amqp_backend,
+                                              virtual_host=amqp_virt_host,
+                                              hosts=transport_hosts,
+                                              aliases=None)
+
         self.TRANSPORT = oslo_msg.get_transport(CONF, url=transport_url)
 
+    def _createTransportHosts(self, username, password, hosts):
+        """Returns a list of oslo.messaging.TransportHost objects."""
+        transport_hosts = []
+
+        for host in hosts:
+            host = host.strip()
+            host_name, host_port = host.split(":")
+
+            if not host_port:
+                msg = "Invalid hosts value: %s. It should be"\
+                      " in hostname:port format" % host
+                raise ValueError(msg)
+
+            try:
+                host_port = int(host_port)
+            except ValueError:
+                msg = "Invalid port value: %s. It should be an integer"
+                raise ValueError(msg % host_port)
+
+            transport_hosts.append(oslo_msg.TransportHost(
+                hostname=host_name,
+                port=host_port,
+                username=username,
+                password=password))
+        return transport_hosts
+
     def getTarget(self, topic, exchange=None, namespace=None,
                   version=None, server=None):
         return oslo_msg.Target(topic=topic,
@@ -343,6 +380,10 @@ class NovaManager(Manager):
                        help="the amqp backend tpye (e.g. rabbit, qpid)",
                        default=None,
                        required=True),
+            cfg.ListOpt("amqp_hosts",
+                        help="AMQP HA cluster host:port pairs",
+                        default=None,
+                        required=False),
             cfg.StrOpt("amqp_host",
                        help="the amqp host name",
                        default="localhost",
@@ -428,6 +469,8 @@ class NovaManager(Manager):
 
         amqp_backend = self.getParameter("amqp_backend", fallback=True)
 
+        amqp_hosts = self.getParameter("amqp_hosts")
+
         amqp_host = self.getParameter("amqp_host")
 
         amqp_port = self.getParameter("amqp_port")
@@ -448,22 +491,17 @@ class NovaManager(Manager):
 
         self.getParameter("metadata_proxy_shared_secret", fallback=True)
 
+        if not amqp_hosts:
+            amqp_hosts = ["%s:%s" % (amqp_host, amqp_port)]
         try:
             LOG.debug("setting up the NOVA database connection: %s"
                       % db_connection)
 
-            self.db_engine = create_engine(db_connection)
+            self.db_engine = create_engine(db_connection, pool_recycle=30)
 
-            transport_url = "{b}://{user}:{password}@{host}:{port}/{virt_host}"
-            transport_url = transport_url.format(
-                b=amqp_backend,
-                user=amqp_user,
-                password=amqp_password,
-                host=amqp_host,
-                port=amqp_port,
-                virt_host=amqp_virt_host)
-
-            self.messagingAPI = MessagingAPI(transport_url)
+            self.messagingAPI = MessagingAPI(amqp_backend, amqp_user,
+                                             amqp_password, amqp_hosts,
+                                             amqp_virt_host)
 
             self.novaBaseRPCAPI = NovaBaseRPCAPI(conductor_topic,
                                                  self.messagingAPI)