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, 3 insertions, 2 deletions

diff --git a/cloudinit/config/cc_ssh_import_id.py b/cloudinit/config/cc_ssh_import_id.py
index 63f87298..856e5a9e 100755
--- a/cloudinit/config/cc_ssh_import_id.py
+++ b/cloudinit/config/cc_ssh_import_id.py
@@ -31,6 +31,7 @@ either ``lp:`` for launchpad or ``gh:`` for github to the username.
 """
 
 from cloudinit.distros import ug_util
+from cloudinit import subp
 from cloudinit import util
 import pwd
 
@@ -101,8 +102,8 @@ def import_ssh_ids(ids, user, log):
     log.debug("Importing SSH ids for user %s.", user)
 
     try:
-        util.subp(cmd, capture=False)
-    except util.ProcessExecutionError as exc:
+        subp.subp(cmd, capture=False)
+    except subp.ProcessExecutionError as exc:
         util.logexc(log, "Failed to run command to import %s SSH ids", user)
         raise exc