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, 5 insertions, 4 deletions

diff --git a/tests/cloud_tests/platforms/platforms.py b/tests/cloud_tests/platforms/platforms.py
index bebdf1c6..58f65e52 100644
--- a/tests/cloud_tests/platforms/platforms.py
+++ b/tests/cloud_tests/platforms/platforms.py
@@ -7,6 +7,7 @@ import shutil
 from simplestreams import filters, mirrors
 from simplestreams import util as s_util
 
+from cloudinit import subp
 from cloudinit import util as c_util
 
 from tests.cloud_tests import util
@@ -48,10 +49,10 @@ class Platform(object):
         if os.path.exists(filename):
             c_util.del_file(filename)
 
-        c_util.subp(['ssh-keygen', '-m', 'PEM', '-t', 'rsa', '-b', '4096',
-                     '-f', filename, '-P', '',
-                     '-C', 'ubuntu@cloud_test'],
-                    capture=True)
+        subp.subp(['ssh-keygen', '-m', 'PEM', '-t', 'rsa', '-b', '4096',
+                   '-f', filename, '-P', '',
+                   '-C', 'ubuntu@cloud_test'],
+                  capture=True)
 
     @staticmethod
     def _query_streams(img_conf, img_filter):