merge from trunk

1 files changed, 76 insertions, 21 deletions

diff --git a/cloudinit/sources/DataSourceCloudStack.py b/cloudinit/sources/DataSourceCloudStack.py
index c0e1a23c..81c8cda9 100644
--- a/cloudinit/sources/DataSourceCloudStack.py
+++ b/cloudinit/sources/DataSourceCloudStack.py
@@ -3,10 +3,12 @@
 #    Copyright (C) 2012 Canonical Ltd.
 #    Copyright (C) 2012 Cosmin Luta
 #    Copyright (C) 2012 Yahoo! Inc.
+#    Copyright (C) 2012 Gerard Dethier
 #
 #    Author: Cosmin Luta <q4break@gmail.com>
 #    Author: Scott Moser <scott.moser@canonical.com>
 #    Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#    Author: Gerard Dethier <g.dethier@gmail.com>
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License version 3, as
@@ -20,9 +22,6 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from socket import inet_ntoa
-from struct import pack
-
 import os
 import time
 
@@ -31,6 +30,8 @@ from cloudinit import log as logging
 from cloudinit import sources
 from cloudinit import url_helper as uhelp
 from cloudinit import util
+from socket import inet_ntoa
+from struct import pack
 
 LOG = logging.getLogger(__name__)
 
@@ -40,24 +41,12 @@ class DataSourceCloudStack(sources.DataSource):
         sources.DataSource.__init__(self, sys_cfg, distro, paths)
         self.seed_dir = os.path.join(paths.seed_dir, 'cs')
         # Cloudstack has its metadata/userdata URLs located at
-        # http://<default-gateway-ip>/latest/
+        # http://<virtual-router-ip>/latest/
         self.api_ver = 'latest'
-        gw_addr = self.get_default_gateway()
-        if not gw_addr:
-            raise RuntimeError("No default gateway found!")
-        self.metadata_address = "http://%s/" % (gw_addr)
-
-    def get_default_gateway(self):
-        """Returns the default gateway ip address in the dotted format."""
-        lines = util.load_file("/proc/net/route").splitlines()
-        for line in lines:
-            items = line.split("\t")
-            if items[1] == "00000000":
-                # Found the default route, get the gateway
-                gw = inet_ntoa(pack("<L", int(items[2], 16)))
-                LOG.debug("Found default route, gateway is %s", gw)
-                return gw
-        return None
+        vr_addr = get_vr_address()
+        if not vr_addr:
+            raise RuntimeError("No virtual router found!")
+        self.metadata_address = "http://%s/" % (vr_addr)
 
     def _get_url_settings(self):
         mcfg = self.ds_cfg
@@ -87,7 +76,7 @@ class DataSourceCloudStack(sources.DataSource):
 
         (max_wait, timeout) = self._get_url_settings()
 
-        urls = [self.metadata_address]
+        urls = [self.metadata_address + "/latest/meta-data/instance-id"]
         start_time = time.time()
         url = uhelp.wait_for_url(urls=urls, max_wait=max_wait,
                                 timeout=timeout, status_cb=LOG.warn)
@@ -132,6 +121,72 @@ class DataSourceCloudStack(sources.DataSource):
         return self.metadata['availability-zone']
 
 
+def get_default_gateway():
+    # Returns the default gateway ip address in the dotted format.
+    lines = util.load_file("/proc/net/route").splitlines()
+    for line in lines:
+        items = line.split("\t")
+        if items[1] == "00000000":
+            # Found the default route, get the gateway
+            gw = inet_ntoa(pack("<L", int(items[2], 16)))
+            LOG.debug("Found default route, gateway is %s", gw)
+            return gw
+    return None
+
+
+def get_dhclient_d():
+    # find lease files directory
+    supported_dirs = ["/var/lib/dhclient", "/var/lib/dhcp"]
+    for d in supported_dirs:
+        if os.path.exists(d):
+            LOG.debug("Using %s lease directory", d)
+            return d
+    return None
+
+
+def get_latest_lease():
+    # find latest lease file
+    lease_d = get_dhclient_d()
+    if not lease_d:
+        return None
+    lease_files = os.listdir(lease_d)
+    latest_mtime = -1
+    latest_file = None
+    for file_name in lease_files:
+        if file_name.endswith(".lease") or file_name.endswith(".leases"):
+            abs_path = os.path.join(lease_d, file_name)
+            mtime = os.path.getmtime(abs_path)
+            if mtime > latest_mtime:
+                latest_mtime = mtime
+                latest_file = abs_path
+    return latest_file
+
+
+def get_vr_address():
+    # Get the address of the virtual router via dhcp leases
+    # see http://bit.ly/T76eKC for documentation on the virtual router.
+    # If no virtual router is detected, fallback on default gateway.
+    lease_file = get_latest_lease()
+    if not lease_file:
+        LOG.debug("No lease file found, using default gateway")
+        return get_default_gateway()
+
+    latest_address = None
+    with open(lease_file, "r") as fd:
+        for line in fd:
+            if "dhcp-server-identifier" in line:
+                words = line.strip(" ;\r\n").split(" ")
+                if len(words) > 2:
+                    dhcp = words[2]
+                    LOG.debug("Found DHCP identifier %s", dhcp)
+                    latest_address = dhcp
+    if not latest_address:
+        # No virtual router found, fallback on default gateway
+        LOG.debug("No DHCP found, using default gateway")
+        return get_default_gateway()
+    return latest_address
+
+
 # Used to match classes to dependencies
 datasources = [
   (DataSourceCloudStack, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),