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, 3 deletions

diff --git a/tests/unittests/test_datasource/test_smartos.py b/tests/unittests/test_datasource/test_smartos.py
index f1ab1d7a..5847a384 100644
--- a/tests/unittests/test_datasource/test_smartos.py
+++ b/tests/unittests/test_datasource/test_smartos.py
@@ -32,8 +32,8 @@ from cloudinit.sources.DataSourceSmartOS import (
 from cloudinit.event import EventType
 
 from cloudinit import helpers as c_helpers
-from cloudinit.util import (
-    b64e, subp, ProcessExecutionError, which, write_file)
+from cloudinit.util import (b64e, write_file)
+from cloudinit.subp import (subp, ProcessExecutionError, which)
 
 from cloudinit.tests.helpers import (
     CiTestCase, mock, FilesystemMockingTestCase, skipIf)
@@ -667,7 +667,7 @@ class TestIdentifyFile(CiTestCase):
         with self.allow_subp(["file"]):
             self.assertEqual("text/plain", identify_file(fname))
 
-    @mock.patch(DSMOS + ".util.subp")
+    @mock.patch(DSMOS + ".subp.subp")
     def test_returns_none_on_error(self, m_subp):
         """On 'file' execution error, None should be returned."""
         m_subp.side_effect = ProcessExecutionError("FILE_FAILED", exit_code=99)