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.

4 files changed, 15 insertions, 12 deletions

diff --git a/cloudinit/analyze/dump.py b/cloudinit/analyze/dump.py
index 939c3126..62ad51fe 100644
--- a/cloudinit/analyze/dump.py
+++ b/cloudinit/analyze/dump.py
@@ -4,6 +4,7 @@ import calendar
 from datetime import datetime
 import sys
 
+from cloudinit import subp
 from cloudinit import util
 
 stage_to_description = {
@@ -51,7 +52,7 @@ def parse_timestamp(timestampstr):
 
 
 def parse_timestamp_from_date(timestampstr):
-    out, _ = util.subp(['date', '+%s.%3N', '-d', timestampstr])
+    out, _ = subp.subp(['date', '+%s.%3N', '-d', timestampstr])
     timestamp = out.strip()
     return float(timestamp)
 
diff --git a/cloudinit/analyze/show.py b/cloudinit/analyze/show.py
index fb152b1d..cca1fa7f 100644
--- a/cloudinit/analyze/show.py
+++ b/cloudinit/analyze/show.py
@@ -11,6 +11,7 @@ import os
 import time
 import sys
 
+from cloudinit import subp
 from cloudinit import util
 from cloudinit.distros import uses_systemd
 
@@ -155,7 +156,7 @@ class SystemctlReader(object):
         :return: whether the subp call failed or not
         '''
         try:
-            value, err = util.subp(self.args, capture=True)
+            value, err = subp.subp(self.args, capture=True)
             if err:
                 return err
             self.epoch = value
@@ -215,7 +216,7 @@ def gather_timestamps_using_dmesg():
     with gather_timestamps_using_systemd
     '''
     try:
-        data, _ = util.subp(['dmesg'], capture=True)
+        data, _ = subp.subp(['dmesg'], capture=True)
         split_entries = data[0].splitlines()
         for i in split_entries:
             if i.decode('UTF-8').find('user') != -1:
diff --git a/cloudinit/analyze/tests/test_boot.py b/cloudinit/analyze/tests/test_boot.py
index f4001c14..f69423c3 100644
--- a/cloudinit/analyze/tests/test_boot.py
+++ b/cloudinit/analyze/tests/test_boot.py
@@ -25,7 +25,7 @@ class TestDistroChecker(CiTestCase):
                                       m_get_linux_distro, m_is_FreeBSD):
         self.assertEqual(err_code, dist_check_timestamp())
 
-    @mock.patch('cloudinit.util.subp', return_value=(0, 1))
+    @mock.patch('cloudinit.subp.subp', return_value=(0, 1))
     def test_subp_fails(self, m_subp):
         self.assertEqual(err_code, dist_check_timestamp())
 
@@ -42,7 +42,7 @@ class TestSystemCtlReader(CiTestCase):
         with self.assertRaises(RuntimeError):
             reader.parse_epoch_as_float()
 
-    @mock.patch('cloudinit.util.subp', return_value=('U=1000000', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=1000000', None))
     def test_systemctl_works_correctly_threshold(self, m_subp):
         reader = SystemctlReader('dummyProperty', 'dummyParameter')
         self.assertEqual(1.0, reader.parse_epoch_as_float())
@@ -50,12 +50,12 @@ class TestSystemCtlReader(CiTestCase):
         self.assertTrue(thresh < 1e-6)
         self.assertTrue(thresh > (-1 * 1e-6))
 
-    @mock.patch('cloudinit.util.subp', return_value=('U=0', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=0', None))
     def test_systemctl_succeed_zero(self, m_subp):
         reader = SystemctlReader('dummyProperty', 'dummyParameter')
         self.assertEqual(0.0, reader.parse_epoch_as_float())
 
-    @mock.patch('cloudinit.util.subp', return_value=('U=1', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=1', None))
     def test_systemctl_succeed_distinct(self, m_subp):
         reader = SystemctlReader('dummyProperty', 'dummyParameter')
         val1 = reader.parse_epoch_as_float()
@@ -64,13 +64,13 @@ class TestSystemCtlReader(CiTestCase):
         val2 = reader2.parse_epoch_as_float()
         self.assertNotEqual(val1, val2)
 
-    @mock.patch('cloudinit.util.subp', return_value=('100', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('100', None))
     def test_systemctl_epoch_not_splittable(self, m_subp):
         reader = SystemctlReader('dummyProperty', 'dummyParameter')
         with self.assertRaises(IndexError):
             reader.parse_epoch_as_float()
 
-    @mock.patch('cloudinit.util.subp', return_value=('U=foobar', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=foobar', None))
     def test_systemctl_cannot_convert_epoch_to_float(self, m_subp):
         reader = SystemctlReader('dummyProperty', 'dummyParameter')
         with self.assertRaises(ValueError):
@@ -130,7 +130,7 @@ class TestAnalyzeBoot(CiTestCase):
         self.assertEqual(err_string, data)
 
     @mock.patch("cloudinit.util.is_container", return_value=True)
-    @mock.patch('cloudinit.util.subp', return_value=('U=1000000', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=1000000', None))
     def test_container_no_ci_log_line(self, m_is_container, m_subp):
         path = os.path.dirname(os.path.abspath(__file__))
         log_path = path + '/boot-test.log'
@@ -148,7 +148,7 @@ class TestAnalyzeBoot(CiTestCase):
         self.assertEqual(FAIL_CODE, finish_code)
 
     @mock.patch("cloudinit.util.is_container", return_value=True)
-    @mock.patch('cloudinit.util.subp', return_value=('U=1000000', None))
+    @mock.patch('cloudinit.subp.subp', return_value=('U=1000000', None))
     @mock.patch('cloudinit.analyze.__main__._get_events', return_value=[{
         'name': 'init-local', 'description': 'starting search', 'timestamp':
         100000}])
diff --git a/cloudinit/analyze/tests/test_dump.py b/cloudinit/analyze/tests/test_dump.py
index d6fbd381..dac1efb6 100644
--- a/cloudinit/analyze/tests/test_dump.py
+++ b/cloudinit/analyze/tests/test_dump.py
@@ -5,7 +5,8 @@ from textwrap import dedent
 
 from cloudinit.analyze.dump import (
     dump_events, parse_ci_logline, parse_timestamp)
-from cloudinit.util import which, write_file
+from cloudinit.util import write_file
+from cloudinit.subp import which
 from cloudinit.tests.helpers import CiTestCase, mock, skipIf