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.

6 files changed, 14 insertions, 13 deletions

diff --git a/tests/unittests/test_distros/test_create_users.py b/tests/unittests/test_distros/test_create_users.py
index ef11784d..94ab052d 100644
--- a/tests/unittests/test_distros/test_create_users.py
+++ b/tests/unittests/test_distros/test_create_users.py
@@ -46,7 +46,7 @@ class MyBaseDistro(distros.Distro):
 
 
 @mock.patch("cloudinit.distros.util.system_is_snappy", return_value=False)
-@mock.patch("cloudinit.distros.util.subp")
+@mock.patch("cloudinit.distros.subp.subp")
 class TestCreateUser(CiTestCase):
 
     with_logs = True
@@ -240,7 +240,7 @@ class TestCreateUser(CiTestCase):
             [mock.call(set(['auth1']), user),  # not disabled
              mock.call(set(['key1']), 'foouser', options=disable_prefix)])
 
-    @mock.patch("cloudinit.distros.util.which")
+    @mock.patch("cloudinit.distros.subp.which")
     def test_lock_with_usermod_if_no_passwd(self, m_which, m_subp,
                                             m_is_snappy):
         """Lock uses usermod --lock if no 'passwd' cmd available."""
@@ -250,7 +250,7 @@ class TestCreateUser(CiTestCase):
             [mock.call(['usermod', '--lock', 'bob'])],
             m_subp.call_args_list)
 
-    @mock.patch("cloudinit.distros.util.which")
+    @mock.patch("cloudinit.distros.subp.which")
     def test_lock_with_passwd_if_available(self, m_which, m_subp,
                                            m_is_snappy):
         """Lock with only passwd will use passwd."""
@@ -260,7 +260,7 @@ class TestCreateUser(CiTestCase):
             [mock.call(['passwd', '-l', 'bob'])],
             m_subp.call_args_list)
 
-    @mock.patch("cloudinit.distros.util.which")
+    @mock.patch("cloudinit.distros.subp.which")
     def test_lock_raises_runtime_if_no_commands(self, m_which, m_subp,
                                                 m_is_snappy):
         """Lock with no commands available raises RuntimeError."""
diff --git a/tests/unittests/test_distros/test_debian.py b/tests/unittests/test_distros/test_debian.py
index da16a797..7ff8240b 100644
--- a/tests/unittests/test_distros/test_debian.py
+++ b/tests/unittests/test_distros/test_debian.py
@@ -5,7 +5,7 @@ from cloudinit import util
 from cloudinit.tests.helpers import (FilesystemMockingTestCase, mock)
 
 
-@mock.patch("cloudinit.distros.debian.util.subp")
+@mock.patch("cloudinit.distros.debian.subp.subp")
 class TestDebianApplyLocale(FilesystemMockingTestCase):
 
     def setUp(self):
diff --git a/tests/unittests/test_distros/test_freebsd.py b/tests/unittests/test_distros/test_freebsd.py
index 8af253a2..be565b04 100644
--- a/tests/unittests/test_distros/test_freebsd.py
+++ b/tests/unittests/test_distros/test_freebsd.py
@@ -8,7 +8,7 @@ import os
 
 class TestDeviceLookUp(CiTestCase):
 
-    @mock.patch('cloudinit.util.subp')
+    @mock.patch('cloudinit.subp.subp')
     def test_find_freebsd_part_label(self, mock_subp):
         glabel_out = '''
 gptid/fa52d426-c337-11e6-8911-00155d4c5e47  N/A  da0p1
@@ -19,7 +19,7 @@ gptid/fa52d426-c337-11e6-8911-00155d4c5e47  N/A  da0p1
         res = find_freebsd_part("/dev/label/rootfs")
         self.assertEqual("da0p2", res)
 
-    @mock.patch('cloudinit.util.subp')
+    @mock.patch('cloudinit.subp.subp')
     def test_find_freebsd_part_gpt(self, mock_subp):
         glabel_out = '''
                                 gpt/bootfs  N/A  vtbd0p1
diff --git a/tests/unittests/test_distros/test_generic.py b/tests/unittests/test_distros/test_generic.py
index 02b334e3..6b6c1566 100644
--- a/tests/unittests/test_distros/test_generic.py
+++ b/tests/unittests/test_distros/test_generic.py
@@ -245,7 +245,7 @@ class TestGenericDistro(helpers.FilesystemMockingTestCase):
         for d_name in ("ubuntu", "rhel"):
             cls = distros.fetch(d_name)
             d = cls(d_name, {}, None)
-            with mock.patch("cloudinit.util.subp") as m_subp:
+            with mock.patch("cloudinit.subp.subp") as m_subp:
                 d.expire_passwd("myuser")
             m_subp.assert_called_once_with(["passwd", "--expire", "myuser"])
 
@@ -253,7 +253,7 @@ class TestGenericDistro(helpers.FilesystemMockingTestCase):
         """Test FreeBSD.expire_passwd uses the pw command."""
         cls = distros.fetch("freebsd")
         d = cls("freebsd", {}, None)
-        with mock.patch("cloudinit.util.subp") as m_subp:
+        with mock.patch("cloudinit.subp.subp") as m_subp:
             d.expire_passwd("myuser")
         m_subp.assert_called_once_with(
             ["pw", "usermod", "myuser", "-p", "01-Jan-1970"])
diff --git a/tests/unittests/test_distros/test_netconfig.py b/tests/unittests/test_distros/test_netconfig.py
index 910207ca..8d7b09c8 100644
--- a/tests/unittests/test_distros/test_netconfig.py
+++ b/tests/unittests/test_distros/test_netconfig.py
@@ -12,6 +12,7 @@ from cloudinit import helpers
 from cloudinit import settings
 from cloudinit.tests.helpers import (
     FilesystemMockingTestCase, dir2dict)
+from cloudinit import subp
 from cloudinit import util
 
 
@@ -688,6 +689,6 @@ class TestNetCfgDistroArch(TestNetCfgDistroBase):
 
 
 def get_mode(path, target=None):
-    return os.stat(util.target_path(target, path)).st_mode & 0o777
+    return os.stat(subp.target_path(target, path)).st_mode & 0o777
 
 # vi: ts=4 expandtab
diff --git a/tests/unittests/test_distros/test_user_data_normalize.py b/tests/unittests/test_distros/test_user_data_normalize.py
index a6faf0ef..fa48410a 100644
--- a/tests/unittests/test_distros/test_user_data_normalize.py
+++ b/tests/unittests/test_distros/test_user_data_normalize.py
@@ -307,7 +307,7 @@ class TestUGNormalize(TestCase):
         self.assertEqual({'default': False}, users['joe'])
         self.assertEqual({'default': False}, users['bob'])
 
-    @mock.patch('cloudinit.util.subp')
+    @mock.patch('cloudinit.subp.subp')
     def test_create_snap_user(self, mock_subp):
         mock_subp.side_effect = [('{"username": "joe", "ssh-key-count": 1}\n',
                                   '')]
@@ -326,7 +326,7 @@ class TestUGNormalize(TestCase):
         mock_subp.assert_called_with(snapcmd, capture=True, logstring=snapcmd)
         self.assertEqual(username, 'joe')
 
-    @mock.patch('cloudinit.util.subp')
+    @mock.patch('cloudinit.subp.subp')
     def test_create_snap_user_known(self, mock_subp):
         mock_subp.side_effect = [('{"username": "joe", "ssh-key-count": 1}\n',
                                   '')]
@@ -348,7 +348,7 @@ class TestUGNormalize(TestCase):
 
     @mock.patch('cloudinit.util.system_is_snappy')
     @mock.patch('cloudinit.util.is_group')
-    @mock.patch('cloudinit.util.subp')
+    @mock.patch('cloudinit.subp.subp')
     def test_add_user_on_snappy_system(self, mock_subp, mock_isgrp,
                                        mock_snappy):
         mock_isgrp.return_value = False