Merge lp:~harlowja/cloud-init/ds-reset-fix into lp:~cloud-init-dev/cloud-init/trunk

[Joshua Harlow]

[lp:~harlowja/cloud-init/ds-reset-fix]

742. By Joshua Harlow on 2012-12-05

Move the 'fetch_base_config' to be a top level module function.

[Scott Moser (smoser)]

I'm calling this "merged" at revno 747 that I just pushed.
I picked the fetch_base_config() method out but did not take the other changes.

The request for this review came because I had missed some function when backporting something to quantal, and was seeing something I thought was related (that a 'cloud' passed to a config did not have a distro).

That was fixed by pulling in revno 720 and 722 though.

review: Approve

=== modified file 'cloudinit/stages.py'
--- cloudinit/stages.py	2012-11-13 03:11:34 +0000
+++ cloudinit/stages.py	2012-12-05 21:15:25 +0000
@@ -50,6 +50,22 @@
 NULL_DATA_SOURCE = None
 
 
+def fetch_base_config():
+    base_cfgs = []
+    default_cfg = util.get_builtin_cfg()
+    kern_contents = util.read_cc_from_cmdline()
+    # Kernel/cmdline parameters override system config
+    if kern_contents:
+        base_cfgs.append(util.load_yaml(kern_contents, default={}))
+    # Anything in your conf.d location??
+    # or the 'default' cloud.cfg location???
+    base_cfgs.append(util.read_conf_with_confd(CLOUD_CONFIG))
+    # And finally the default gets to play
+    if default_cfg:
+        base_cfgs.append(default_cfg)
+    return util.mergemanydict(base_cfgs)
+
+
 class Init(object):
     def __init__(self, ds_deps=None):
         if ds_deps is not None:
@@ -63,23 +79,29 @@
         # 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
@@ -103,9 +125,11 @@
 
     @property
     def paths(self):
-        if not self._paths:
+        if self._paths is None:
             path_info = self._extract_cfg('paths')
             self._paths = helpers.Paths(path_info, self.datasource)
+            # TODO(harlowja): should we readjust the datasources
+            # path attribute after this has been loaded/reloaded?
         return self._paths
 
     def _initial_subdirs(self):
@@ -155,29 +179,13 @@
         # None check so that we don't keep on re-loading if empty
         if self._cfg is None:
             self._cfg = self._read_cfg(extra_fns)
-            # LOG.debug("Loaded 'init' config %s", self._cfg)
-
-    def _read_base_cfg(self):
-        base_cfgs = []
-        default_cfg = util.get_builtin_cfg()
-        kern_contents = util.read_cc_from_cmdline()
-        # Kernel/cmdline parameters override system config
-        if kern_contents:
-            base_cfgs.append(util.load_yaml(kern_contents, default={}))
-        # Anything in your conf.d location??
-        # or the 'default' cloud.cfg location???
-        base_cfgs.append(util.read_conf_with_confd(CLOUD_CONFIG))
-        # And finally the default gets to play
-        if default_cfg:
-            base_cfgs.append(default_cfg)
-        return util.mergemanydict(base_cfgs)
 
     def _read_cfg(self, extra_fns):
         no_cfg_paths = helpers.Paths({}, self.datasource)
         merger = helpers.ConfigMerger(paths=no_cfg_paths,
                                       datasource=self.datasource,
                                       additional_fns=extra_fns,
-                                      base_cfg=self._read_base_cfg())
+                                      base_cfg=fetch_base_config())
         return merger.cfg
 
     def _restore_from_cache(self):