Move subp into its own module. (#416)

This was painful, but it finishes a TODO from cloudinit/subp.py.

It moves the following from util to subp:
  ProcessExecutionError
  subp
  which
  target_path

I moved subp_blob_in_tempfile into cc_chef, which is its only caller.
That saved us from having to deal with it using write_file
and temp_utils from subp (which does not import any cloudinit things now).

It is arguable that 'target_path' could be moved to a 'path_utils' or
something, but in order to use it from subp and also from utils,
we had to get it out of utils.

1 files changed, 4 insertions, 4 deletions

diff --git a/cloudinit/config/cc_emit_upstart.py b/cloudinit/config/cc_emit_upstart.py
index b342e04d..b1d99f97 100644
--- a/cloudinit/config/cc_emit_upstart.py
+++ b/cloudinit/config/cc_emit_upstart.py
@@ -25,7 +25,7 @@ import os
 
 from cloudinit import log as logging
 from cloudinit.settings import PER_ALWAYS
-from cloudinit import util
+from cloudinit import subp
 
 frequency = PER_ALWAYS
 
@@ -43,9 +43,9 @@ def is_upstart_system():
         del myenv['UPSTART_SESSION']
     check_cmd = ['initctl', 'version']
     try:
-        (out, _err) = util.subp(check_cmd, env=myenv)
+        (out, _err) = subp.subp(check_cmd, env=myenv)
         return 'upstart' in out
-    except util.ProcessExecutionError as e:
+    except subp.ProcessExecutionError as e:
         LOG.debug("'%s' returned '%s', not using upstart",
                   ' '.join(check_cmd), e.exit_code)
     return False
@@ -66,7 +66,7 @@ def handle(name, _cfg, cloud, log, args):
     for n in event_names:
         cmd = ['initctl', 'emit', str(n), 'CLOUD_CFG=%s' % cfgpath]
         try:
-            util.subp(cmd)
+            subp.subp(cmd)
         except Exception as e:
             # TODO(harlowja), use log exception from utils??
             log.warning("Emission of upstart event %s failed due to: %s", n, e)