tests: Disallow use of util.subp except for where needed.

In many cases, cloud-init uses 'util.subp' to run a subprocess.
This is not really desirable in our unit tests as it makes the tests
dependent upon existance of those utilities.

The change here is to modify the base test case class (CiTestCase) to
raise exception any time subp is called.  Then, fix all callers.
For cases where subp is necessary or actually desired, we can use it
via
  a.) context hander CiTestCase.allow_subp(value)
  b.) class level self.allowed_subp = value

Both cases the value is a list of acceptable executable names that
will be called (essentially argv[0]).

Some cleanups in AltCloud were done as the code was being updated.

1 files changed, 33 insertions, 53 deletions

diff --git a/cloudinit/analyze/tests/test_dump.py b/cloudinit/analyze/tests/test_dump.py
index f4c42841..db2a667b 100644
--- a/cloudinit/analyze/tests/test_dump.py
+++ b/cloudinit/analyze/tests/test_dump.py
@@ -5,8 +5,8 @@ from textwrap import dedent
 
 from cloudinit.analyze.dump import (
     dump_events, parse_ci_logline, parse_timestamp)
-from cloudinit.util import subp, write_file
-from cloudinit.tests.helpers import CiTestCase
+from cloudinit.util import which, write_file
+from cloudinit.tests.helpers import CiTestCase, mock, skipIf
 
 
 class TestParseTimestamp(CiTestCase):
@@ -15,21 +15,9 @@ class TestParseTimestamp(CiTestCase):
         """Logs with cloud-init detailed formats will be properly parsed."""
         trusty_fmt = '%Y-%m-%d %H:%M:%S,%f'
         trusty_stamp = '2016-09-12 14:39:20,839'
-
-        parsed = parse_timestamp(trusty_stamp)
-
-        # convert ourselves
         dt = datetime.strptime(trusty_stamp, trusty_fmt)
-        expected = float(dt.strftime('%s.%f'))
-
-        # use date(1)
-        out, _err = subp(['date', '+%s.%3N', '-d', trusty_stamp])
-        timestamp = out.strip()
-        date_ts = float(timestamp)
-
-        self.assertEqual(expected, parsed)
-        self.assertEqual(expected, date_ts)
-        self.assertEqual(date_ts, parsed)
+        self.assertEqual(
+            float(dt.strftime('%s.%f')), parse_timestamp(trusty_stamp))
 
     def test_parse_timestamp_handles_syslog_adding_year(self):
         """Syslog timestamps lack a year. Add year and properly parse."""
@@ -39,17 +27,9 @@ class TestParseTimestamp(CiTestCase):
         # convert stamp ourselves by adding the missing year value
         year = datetime.now().year
         dt = datetime.strptime(syslog_stamp + " " + str(year), syslog_fmt)
-        expected = float(dt.strftime('%s.%f'))
-        parsed = parse_timestamp(syslog_stamp)
-
-        # use date(1)
-        out, _ = subp(['date', '+%s.%3N', '-d', syslog_stamp])
-        timestamp = out.strip()
-        date_ts = float(timestamp)
-
-        self.assertEqual(expected, parsed)
-        self.assertEqual(expected, date_ts)
-        self.assertEqual(date_ts, parsed)
+        self.assertEqual(
+            float(dt.strftime('%s.%f')),
+            parse_timestamp(syslog_stamp))
 
     def test_parse_timestamp_handles_journalctl_format_adding_year(self):
         """Journalctl precise timestamps lack a year. Add year and parse."""
@@ -59,37 +39,22 @@ class TestParseTimestamp(CiTestCase):
         # convert stamp ourselves by adding the missing year value
         year = datetime.now().year
         dt = datetime.strptime(journal_stamp + " " + str(year), journal_fmt)
-        expected = float(dt.strftime('%s.%f'))
-        parsed = parse_timestamp(journal_stamp)
-
-        # use date(1)
-        out, _ = subp(['date', '+%s.%6N', '-d', journal_stamp])
-        timestamp = out.strip()
-        date_ts = float(timestamp)
-
-        self.assertEqual(expected, parsed)
-        self.assertEqual(expected, date_ts)
-        self.assertEqual(date_ts, parsed)
+        self.assertEqual(
+            float(dt.strftime('%s.%f')), parse_timestamp(journal_stamp))
 
+    @skipIf(not which("date"), "'date' command not available.")
     def test_parse_unexpected_timestamp_format_with_date_command(self):
-        """Dump sends unexpected timestamp formats to data for processing."""
+        """Dump sends unexpected timestamp formats to date for processing."""
         new_fmt = '%H:%M %m/%d %Y'
         new_stamp = '17:15 08/08'
-
         # convert stamp ourselves by adding the missing year value
         year = datetime.now().year
         dt = datetime.strptime(new_stamp + " " + str(year), new_fmt)
-        expected = float(dt.strftime('%s.%f'))
-        parsed = parse_timestamp(new_stamp)
 
         # use date(1)
-        out, _ = subp(['date', '+%s.%6N', '-d', new_stamp])
-        timestamp = out.strip()
-        date_ts = float(timestamp)
-
-        self.assertEqual(expected, parsed)
-        self.assertEqual(expected, date_ts)
-        self.assertEqual(date_ts, parsed)
+        with self.allow_subp(["date"]):
+            self.assertEqual(
+                float(dt.strftime('%s.%f')), parse_timestamp(new_stamp))
 
 
 class TestParseCILogLine(CiTestCase):
@@ -135,7 +100,9 @@ class TestParseCILogLine(CiTestCase):
             'timestamp': timestamp}
         self.assertEqual(expected, parse_ci_logline(line))
 
-    def test_parse_logline_returns_event_for_finish_events(self):
+    @mock.patch("cloudinit.analyze.dump.parse_timestamp_from_date")
+    def test_parse_logline_returns_event_for_finish_events(self,
+                                                           m_parse_from_date):
         """parse_ci_logline returns a finish event for a parsed log line."""
         line = ('2016-08-30 21:53:25.972325+00:00 y1 [CLOUDINIT]'
                 ' handlers.py[DEBUG]: finish: modules-final: SUCCESS: running'
@@ -147,7 +114,10 @@ class TestParseCILogLine(CiTestCase):
             'origin': 'cloudinit',
             'result': 'SUCCESS',
             'timestamp': 1472594005.972}
+        m_parse_from_date.return_value = "1472594005.972"
         self.assertEqual(expected, parse_ci_logline(line))
+        m_parse_from_date.assert_has_calls(
+            [mock.call("2016-08-30 21:53:25.972325+00:00")])
 
 
 SAMPLE_LOGS = dedent("""\
@@ -162,10 +132,16 @@ Nov 03 06:51:06.074410 x2 cloud-init[106]: [CLOUDINIT] util.py[DEBUG]:\
 class TestDumpEvents(CiTestCase):
     maxDiff = None
 
-    def test_dump_events_with_rawdata(self):
+    @mock.patch("cloudinit.analyze.dump.parse_timestamp_from_date")
+    def test_dump_events_with_rawdata(self, m_parse_from_date):
         """Rawdata is split and parsed into a tuple of events and data"""
+        m_parse_from_date.return_value = "1472594005.972"
         events, data = dump_events(rawdata=SAMPLE_LOGS)
         expected_data = SAMPLE_LOGS.splitlines()
+        self.assertEqual(
+            [mock.call("2016-08-30 21:53:25.972325+00:00")],
+            m_parse_from_date.call_args_list)
+        self.assertEqual(expected_data, data)
         year = datetime.now().year
         dt1 = datetime.strptime(
             'Nov 03 06:51:06.074410 %d' % year, '%b %d %H:%M:%S.%f %Y')
@@ -183,12 +159,14 @@ class TestDumpEvents(CiTestCase):
             'result': 'SUCCESS',
             'timestamp': 1472594005.972}]
         self.assertEqual(expected_events, events)
-        self.assertEqual(expected_data, data)
 
-    def test_dump_events_with_cisource(self):
+    @mock.patch("cloudinit.analyze.dump.parse_timestamp_from_date")
+    def test_dump_events_with_cisource(self, m_parse_from_date):
         """Cisource file is read and parsed into a tuple of events and data."""
         tmpfile = self.tmp_path('logfile')
         write_file(tmpfile, SAMPLE_LOGS)
+        m_parse_from_date.return_value = 1472594005.972
+
         events, data = dump_events(cisource=open(tmpfile))
         year = datetime.now().year
         dt1 = datetime.strptime(
@@ -208,3 +186,5 @@ class TestDumpEvents(CiTestCase):
             'timestamp': 1472594005.972}]
         self.assertEqual(expected_events, events)
         self.assertEqual(SAMPLE_LOGS.splitlines(), [d.strip() for d in data])
+        m_parse_from_date.assert_has_calls(
+            [mock.call("2016-08-30 21:53:25.972325+00:00")])