Complete initial cleanup for refactoring/rework.

Some of the cleanups were the following

1. Using standard (logged) utility functions for sub process work, writing, reading files, and other file system/operating system options
2. Having distrobutions impelement there own subclasses to handle system specifics (if applicable)
3. Having a cloud wrapper that provides just the functionality we want to expose (cloud.py)
4. Using a path class instead of globals for all cloud init paths (it is configured via config)
5. Removal of as much shared global state as possible (there should be none, minus a set of constants)
6. Other various cleanups that remove transforms/handlers/modules from reading/writing/chmoding there own files. 
 a. They should be using util functions to take advantage of the logging that is now enabled in those util functions (very useful for debugging)
7. Urls being read and checked from a single module that serves this and only this purpose (+1 for code organization)
8. Updates to log whenever a transform decides not to run
9. Ensure whenever a exception is thrown (and possibly captured) that the util.logexc function is called 
 a. For debugging, tracing this is important to not just drop them on the floor.
10. Code shuffling into utils.py where it makes sense (and where it could serve a benefit for other code now or in the future)

1 files changed, 30 insertions, 13 deletions

diff --git a/cloudinit/transforms/cc_landscape.py b/cloudinit/transforms/cc_landscape.py
index a4113cbe..48491992 100644
--- a/cloudinit/transforms/cc_landscape.py
+++ b/cloudinit/transforms/cc_landscape.py
@@ -19,14 +19,24 @@
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import os.path
-from cloudinit.CloudConfig import per_instance
-from configobj import ConfigObj
 
-frequency = per_instance
+from StringIO import StringIO
+
+try:
+    from configobj import ConfigObj
+except ImportError:
+    ConfigObj = None
+
+from cloudinit import util
+
+from cloudinit.settings import PER_INSTANCE
+
+frequency = PER_INSTANCE
 
 lsc_client_cfg_file = "/etc/landscape/client.conf"
 
+distros = ['ubuntu']
+
 # defaults taken from stock client.conf in landscape-client 11.07.1.1-0ubuntu2
 lsc_builtincfg = {
   'client': {
@@ -38,36 +48,43 @@ lsc_builtincfg = {
 }
 
 
-def handle(_name, cfg, _cloud, log, _args):
+def handle(name, cfg, _cloud, log, _args):
     """
     Basically turn a top level 'landscape' entry with a 'client' dict
     and render it to ConfigObj format under '[client]' section in
     /etc/landscape/client.conf
     """
+    if not ConfigObj:
+        log.warn("'ConfigObj' support not enabled, running %s disabled", name)
+        return
 
     ls_cloudcfg = cfg.get("landscape", {})
 
     if not isinstance(ls_cloudcfg, dict):
-        raise(Exception("'landscape' existed in config, but not a dict"))
+        raise Exception(("'landscape' key existed in config," 
+                         " but not a dictionary type,"
+                         " is a %s instead"), util.obj_name(ls_cloudcfg))
 
-    merged = mergeTogether([lsc_builtincfg, lsc_client_cfg_file, ls_cloudcfg])
+    merged = merge_together([lsc_builtincfg, lsc_client_cfg_file, ls_cloudcfg])
 
     if not os.path.isdir(os.path.dirname(lsc_client_cfg_file)):
-        os.makedirs(os.path.dirname(lsc_client_cfg_file))
-
-    with open(lsc_client_cfg_file, "w") as fp:
-        merged.write(fp)
+        util.ensure_dir(os.path.dirname(lsc_client_cfg_file))
 
-    log.debug("updated %s" % lsc_client_cfg_file)
+    contents = StringIO()
+    merged.write(contents)
+    util.write_file(lsc_client_cfg_file, contents.getvalue())
+    log.debug("Wrote landscape config file to %s", lsc_client_cfg_file)
 
 
-def mergeTogether(objs):
+def merge_together(objs):
     """
     merge together ConfigObj objects or things that ConfigObj() will take in
     later entries override earlier
     """
     cfg = ConfigObj({})
     for obj in objs:
+        if not obj:
+            continue
         if isinstance(obj, ConfigObj):
             cfg.merge(obj)
         else: