Run cloud config plugins in order

The cloud config plugins were configured as a normal Python dictionary,
thus executing them in a random order, defined by the Python
implementation.

We require runcmd plugin to run last so that it is the last
configuration stage. In the future, we need the order as the groups
plugin is required to run before the users plugin.

Change-Id: I754ef7b15d5c7a12d08a12c876cfb52de64a06cc

Author: ader1990

cloudbaseinit/plugins/common/userdataplugins/cloudconfigplugins/factory.py

@@ -12,27 +12,29 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import collections
+
 from cloudbaseinit.utils import classloader
 
 
 # TODO(cpopa): replace the static list of plugins with something
 # discovered at runtime.
-PLUGINS = {
-    'write_files': 'cloudbaseinit.plugins.common.userdataplugins.'
-                   'cloudconfigplugins.write_files.WriteFilesPlugin',
-    'set_timezone': 'cloudbaseinit.plugins.common.userdataplugins.'
-                    'cloudconfigplugins.set_timezone.SetTimezonePlugin',
-    'timezone': 'cloudbaseinit.plugins.common.userdataplugins.'
-                'cloudconfigplugins.set_timezone.SetTimezonePlugin',
-    'set_hostname': 'cloudbaseinit.plugins.common.userdataplugins.'
-                    'cloudconfigplugins.set_hostname.SetHostnamePlugin',
-    'hostname': 'cloudbaseinit.plugins.common.userdataplugins.'
-                'cloudconfigplugins.set_hostname.SetHostnamePlugin',
-    'ntp': 'cloudbaseinit.plugins.common.userdataplugins.'
-                'cloudconfigplugins.set_ntp.SetNtpPlugin',
-    'runcmd': 'cloudbaseinit.plugins.common.userdataplugins.'
-              'cloudconfigplugins.runcmd.RunCmdPlugin',
-}
+PLUGINS = collections.OrderedDict([
+    ('write_files', 'cloudbaseinit.plugins.common.userdataplugins.'
+                    'cloudconfigplugins.write_files.WriteFilesPlugin'),
+    ('set_timezone', 'cloudbaseinit.plugins.common.userdataplugins.'
+                     'cloudconfigplugins.set_timezone.SetTimezonePlugin'),
+    ('timezone', 'cloudbaseinit.plugins.common.userdataplugins.'
+                 'cloudconfigplugins.set_timezone.SetTimezonePlugin'),
+    ('set_hostname', 'cloudbaseinit.plugins.common.userdataplugins.'
+                     'cloudconfigplugins.set_hostname.SetHostnamePlugin'),
+    ('hostname', 'cloudbaseinit.plugins.common.userdataplugins.'
+                 'cloudconfigplugins.set_hostname.SetHostnamePlugin'),
+    ('ntp', 'cloudbaseinit.plugins.common.userdataplugins.'
+            'cloudconfigplugins.set_ntp.SetNtpPlugin'),
+    ('runcmd', 'cloudbaseinit.plugins.common.userdataplugins.'
+               'cloudconfigplugins.runcmd.RunCmdPlugin'),
+])
 
 
 def load_plugins():