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, 8 insertions, 14 deletions

diff --git a/cloudinit/transforms/cc_byobu.py b/cloudinit/transforms/cc_byobu.py
index e821b261..38586174 100644
--- a/cloudinit/transforms/cc_byobu.py
+++ b/cloudinit/transforms/cc_byobu.py
@@ -18,18 +18,19 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import cloudinit.util as util
-import subprocess
-import traceback
+from cloudinit import util
 
+distros = ['ubuntu', 'debian']
 
-def handle(_name, cfg, _cloud, log, args):
+
+def handle(name, cfg, _cloud, log, args):
     if len(args) != 0:
         value = args[0]
     else:
         value = util.get_cfg_option_str(cfg, "byobu_by_default", "")
 
     if not value:
+        log.debug("Skipping module named %s, no 'byobu' values found", name)
         return
 
     if value == "user" or value == "system":
@@ -38,7 +39,7 @@ def handle(_name, cfg, _cloud, log, args):
     valid = ("enable-user", "enable-system", "enable",
              "disable-user", "disable-system", "disable")
     if not value in valid:
-        log.warn("Unknown value %s for byobu_by_default" % value)
+        log.warn("Unknown value %s for byobu_by_default", value)
 
     mod_user = value.endswith("-user")
     mod_sys = value.endswith("-system")
@@ -65,13 +66,6 @@ def handle(_name, cfg, _cloud, log, args):
 
     cmd = ["/bin/sh", "-c", "%s %s %s" % ("X=0;", shcmd, "exit $X")]
 
-    log.debug("setting byobu to %s" % value)
+    log.debug("Setting byobu to %s", value)
 
-    try:
-        subprocess.check_call(cmd)
-    except subprocess.CalledProcessError as e:
-        log.debug(traceback.format_exc(e))
-        raise Exception("Cmd returned %s: %s" % (e.returncode, cmd))
-    except OSError as e:
-        log.debug(traceback.format_exc(e))
-        raise Exception("Cmd failed to execute: %s" % (cmd))
+    util.subp(cmd)