Merge lp:~allenap/rabbitfixture/untangle-host into lp:rabbitfixture

[Gavin Panella]

Fix port reuse issues when restarting the fixture.

Previously RabbitMQ was started on all addresses, the fq_hostname property was incorrectly using gethostname() regardless of the hostname given, and allocate_ports() only ever checked ports on localhost.

As suggested in the bug report, this branch:

- Only starts RabbitMQ on the specified address. The environment
  variable RABBITMQ_NODE_IP_ADDRESS is used to do this.

- fq_hostname uses the configured hostname.

- allocate_ports() takes a *args of addresses.

[Raphaël Badin (rvb)]

review: Approve

=== modified file 'rabbitfixture/server.py'
--- rabbitfixture/server.py	2012-05-15 18:09:17 +0000
+++ rabbitfixture/server.py	2013-09-16 15:26:00 +0000
@@ -41,21 +41,29 @@
     signal.signal(signal.SIGPIPE, signal.SIG_DFL)
 
 
-def allocate_ports(n=1):
-    """Allocate `n` unused ports.
+def get_port(socket):
+    """Return the port to which a socket is bound."""
+    addr, port = socket.getsockname()
+    return port
+
+
+def allocate_ports(*addrs):
+    """Allocate `len(addrs)` unused ports.
+
+    A port is allocated for each element in `addrs`.
 
     There is a small race condition here (between the time we allocate the
     port, and the time it actually gets used), but for the purposes for which
     this function gets used it isn't a problem in practice.
     """
-    sockets = map(lambda _: socket.socket(), xrange(n))
+    sockets = [socket.socket() for addr in addrs]
     try:
-        for s in sockets:
-            s.bind(('localhost', 0))
-        return map(lambda s: s.getsockname()[1], sockets)
+        for addr, sock in zip(addrs, sockets):
+            sock.bind((addr, 0))
+        return [get_port(sock) for sock in sockets]
     finally:
-        for s in sockets:
-            s.close()
+        for sock in sockets:
+            sock.close()
 
 
 # Pattern to parse rabbitctl status output to find the nodename of a running
@@ -107,7 +115,7 @@
         if self.hostname is None:
             self.hostname = 'localhost'
         if self.port is None:
-            [self.port] = allocate_ports(1)
+            [self.port] = allocate_ports(self.hostname)
         if self.homedir is None:
             self.homedir = self.useFixture(TempDir()).path
         if self.mnesiadir is None:
@@ -121,10 +129,7 @@
     @property
     def fq_nodename(self):
         """The node of the RabbitMQ that is being exported."""
-        # Note that socket.gethostname is recommended by the rabbitctl manpage
-        # even though we're always on localhost, its what the erlang cluster
-        # code wants.
-        return "%s@%s" % (self.nodename, socket.gethostname())
+        return "%s@%s" % (self.nodename, self.hostname)
 
 
 class RabbitServerEnvironment(Fixture):
@@ -134,6 +139,7 @@
 
     - ``RABBITMQ_MNESIA_BASE``
     - ``RABBITMQ_LOG_BASE``
+    - ``RABBITMQ_NODE_IP_ADDRESS``
     - ``RABBITMQ_NODE_PORT``
     - ``RABBITMQ_NODENAME``
     - ``RABBITMQ_PLUGINS_DIR``
@@ -156,14 +162,17 @@
         self.useFixture(EnvironmentVariableFixture(
             "RABBITMQ_LOG_BASE", self.config.homedir))
         self.useFixture(EnvironmentVariableFixture(
+            "RABBITMQ_NODE_IP_ADDRESS",
+            socket.gethostbyname(self.config.hostname)))
+        self.useFixture(EnvironmentVariableFixture(
             "RABBITMQ_NODE_PORT", str(self.config.port)))
         self.useFixture(EnvironmentVariableFixture(
             "RABBITMQ_NODENAME", self.config.fq_nodename))
         self.useFixture(EnvironmentVariableFixture(
             "RABBITMQ_PLUGINS_DIR", self.config.pluginsdir))
         self._errors = []
-        self.addDetail('rabbit-errors',
-            Content(UTF8_TEXT, self._get_errors))
+        self.addDetail('rabbit-errors', Content(
+            UTF8_TEXT, self._get_errors))
 
     def _get_errors(self):
         """Yield all errors as UTF-8 encoded text."""

=== modified file 'rabbitfixture/tests/test_server.py'
--- rabbitfixture/tests/test_server.py	2011-09-29 11:20:28 +0000
+++ rabbitfixture/tests/test_server.py	2013-09-16 15:26:00 +0000
@@ -7,7 +7,6 @@
 
 import os.path
 import socket
-from socket import gethostname
 from textwrap import dedent
 
 from amqplib import client_0_8 as amqp
@@ -15,6 +14,7 @@
 from rabbitfixture.server import (
     get_nodename_from_status,
     RabbitServer,
+    RabbitServerEnvironment,
     RabbitServerResources,
     )
 from testtools import TestCase
@@ -96,10 +96,29 @@
                 seen_homedirs.add(resources.homedir)
 
     def test_fq_nodename(self):
-        with RabbitServerResources(nodename="nibbles") as resources:
-            self.assertEqual(
-                "nibbles@%s" % gethostname(),
-                resources.fq_nodename)
+        resources = self.useFixture(RabbitServerResources(
+            nodename="nibbles", hostname="127.0.0.1"))
+        self.assertEqual("nibbles@127.0.0.1", resources.fq_nodename)
+
+
+class TestRabbitServerEnvironment(TestCase):
+
+    def test_setup(self):
+        config = self.useFixture(RabbitServerResources(
+            hostname="localhost", port=1234, homedir="rabbit/homedir",
+            mnesiadir="rabbit/mnesiadir", logfile="rabbit/logfile",
+            nodename="rabbit-nodename"))
+        self.useFixture(RabbitServerEnvironment(config))
+        expected = {
+            "RABBITMQ_MNESIA_BASE": config.mnesiadir,
+            "RABBITMQ_LOG_BASE": config.homedir,
+            "RABBITMQ_NODE_IP_ADDRESS": socket.gethostbyname(config.hostname),
+            "RABBITMQ_NODE_PORT": str(config.port),
+            "RABBITMQ_NODENAME": config.fq_nodename,
+            "RABBITMQ_PLUGINS_DIR": config.pluginsdir,
+        }
+        self.assertEqual(
+            expected, {name: os.getenv(name) for name in expected})
 
 
 class TestFunctions(TestCase):