ensure a datasource's 'distro' and sys_cfg are updated

After parsing and merging datasource's config, the changes in were not making
it into the datasource's 'distro.

The end result was that the when a config module was called, it's 'cloud'
argument would be updated in 'cloud.distro', but not in
'cloud.datasource.distro'.  This path was required for getting mirror settings
to take affect, because they include information from the datasource.

Ie:
  cc_apt_configure had
    mirror_info = cloud.datasource.get_package_mirror_info()
  the datasource then used *its* copy of sys_cfg to call
    self.distro.get_package_mirror_info
  and *that* distro's sys_cfg had not been updated.

LP: #1090482

2 files changed, 15 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index e4bcdd76..64a6e618 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,8 @@
    option (LP: #1083715)
  - make install of puppet configurable (LP: #1090205) [Craig Tracey]
  - support omnibus installer for chef [Anatoliy Dobrosynets]
+ - fix bug where cloud-config in user-data could not modify system_info
+   settings (LP: #1090482)
 0.7.1:
  - sysvinit: fix missing dependency in cloud-init job for RHEL 5.6 
  - config-drive: map hostname to local-hostname (LP: #1061964)
diff --git a/cloudinit/stages.py b/cloudinit/stages.py
index d9391f39..8d3213b4 100644
--- a/cloudinit/stages.py
+++ b/cloudinit/stages.py
@@ -63,23 +63,29 @@ class Init(object):
         # Changed only when a fetch occurs
         self.datasource = NULL_DATA_SOURCE
 
-    def _reset(self, ds=False):
+    def _reset(self, reset_ds=False):
         # Recreated on access
         self._cfg = None
         self._paths = None
         self._distro = None
-        if ds:
+        if reset_ds:
             self.datasource = NULL_DATA_SOURCE
 
     @property
     def distro(self):
         if not self._distro:
             # Try to find the right class to use
-            scfg = self._extract_cfg('system')
-            name = scfg.pop('distro', 'ubuntu')
-            cls = distros.fetch(name)
-            LOG.debug("Using distro class %s", cls)
-            self._distro = cls(name, scfg, self.paths)
+            system_config = self._extract_cfg('system')
+            distro_name = system_config.pop('distro', 'ubuntu')
+            distro_cls = distros.fetch(distro_name)
+            LOG.debug("Using distro class %s", distro_cls)
+            self._distro = distro_cls(distro_name, system_config, self.paths)
+            # If we have an active datasource we need to adjust
+            # said datasource and move its distro/system config
+            # from whatever it was to a new set...
+            if self.datasource is not NULL_DATA_SOURCE:
+                self.datasource.distro = self._distro
+                self.datasource.sys_cfg = system_config
         return self._distro
 
     @property