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, 14 insertions, 14 deletions

diff --git a/cloudinit/conftest.py b/cloudinit/conftest.py
index 37cbbcda..251bca59 100644
--- a/cloudinit/conftest.py
+++ b/cloudinit/conftest.py
@@ -2,32 +2,32 @@ from unittest import mock
 
 import pytest
 
-from cloudinit import util
+from cloudinit import subp
 
 
 @pytest.yield_fixture(autouse=True)
 def disable_subp_usage(request):
     """
-    Across all (pytest) tests, ensure that util.subp is not invoked.
+    Across all (pytest) tests, ensure that subp.subp is not invoked.
 
     Note that this can only catch invocations where the util module is imported
-    and ``util.subp(...)`` is called.  ``from cloudinit.util import subp``
+    and ``subp.subp(...)`` is called.  ``from cloudinit.subp mport subp``
     imports happen before the patching here (or the CiTestCase monkey-patching)
     happens, so are left untouched.
 
-    To allow a particular test method or class to use util.subp you can set the
+    To allow a particular test method or class to use subp.subp you can set the
     parameter passed to this fixture to False using pytest.mark.parametrize::
 
         @pytest.mark.parametrize("disable_subp_usage", [False], indirect=True)
         def test_whoami(self):
-            util.subp(["whoami"])
+            subp.subp(["whoami"])
 
-    To instead allow util.subp usage for a specific command, you can set the
+    To instead allow subp.subp usage for a specific command, you can set the
     parameter passed to this fixture to that command:
 
         @pytest.mark.parametrize("disable_subp_usage", ["bash"], indirect=True)
         def test_bash(self):
-            util.subp(["bash"])
+            subp.subp(["bash"])
 
     To specify multiple commands, set the parameter to a list (note the
     double-layered list: we specify a single parameter that is itself a list):
@@ -35,8 +35,8 @@ def disable_subp_usage(request):
         @pytest.mark.parametrize(
             "disable_subp_usage", ["bash", "whoami"], indirect=True)
         def test_several_things(self):
-            util.subp(["bash"])
-            util.subp(["whoami"])
+            subp.subp(["bash"])
+            subp.subp(["whoami"])
 
     This fixture (roughly) mirrors the functionality of
     CiTestCase.allowed_subp.  N.B. While autouse fixtures do affect non-pytest
@@ -47,11 +47,11 @@ def disable_subp_usage(request):
     if should_disable:
         if not isinstance(should_disable, (list, str)):
             def side_effect(args, *other_args, **kwargs):
-                raise AssertionError("Unexpectedly used util.subp")
+                raise AssertionError("Unexpectedly used subp.subp")
         else:
             # Look this up before our patch is in place, so we have access to
             # the real implementation in side_effect
-            subp = util.subp
+            real_subp = subp.subp
 
             if isinstance(should_disable, str):
                 should_disable = [should_disable]
@@ -60,12 +60,12 @@ def disable_subp_usage(request):
                 cmd = args[0]
                 if cmd not in should_disable:
                     raise AssertionError(
-                        "Unexpectedly used util.subp to call {} (allowed:"
+                        "Unexpectedly used subp.subp to call {} (allowed:"
                         " {})".format(cmd, ",".join(should_disable))
                     )
-                return subp(args, *other_args, **kwargs)
+                return real_subp(args, *other_args, **kwargs)
 
-        with mock.patch('cloudinit.util.subp', autospec=True) as m_subp:
+        with mock.patch('cloudinit.subp.subp', autospec=True) as m_subp:
             m_subp.side_effect = side_effect
             yield
     else: