Add test for no_monitor behavior.

kano_updater/monitor.py

@@ -139,7 +139,7 @@ def run(cmdargs):
        error code (integer)
     """
     if 'MONITOR_PID' in os.environ:
-        os.execvp(cmdargs[0], cmdargs[1:])
+        os.execvp(cmdargs[0], cmdargs)
 
     os.environ["MONITOR_PID"] = str(os.getpid())
     subproc = subprocess.Popen(cmdargs, shell=False)

tests/conftest.py

@@ -18,3 +18,4 @@
 from tests.fixtures.run_cmd import *
 from tests.fixtures.state import *
 from tests.fixtures.version import *
+from tests.fixtures.environ import *

tests/fixtures/environ.py

@@ -0,0 +1,24 @@
+#
+# environ.py
+#
+# Copyright (C) 2018 Kano Computing Ltd.
+# License: http://www.gnu.org/licenses/gpl-2.0.txt GNU GPL v2
+#
+# Fixture to clean environment
+#
+
+
+import pytest
+import os
+
+
+@pytest.fixture(scope='function', params=(True, False))
+def monitor_pid():
+    """
+    ensures environment variable MONITOR_PID is not propagated across tests
+    """
+    try:        
+        del os.environ["MONITOR_PID"]
+    except:
+        pass
+

tests/monitor_wrap.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+#
+# monitor_wrap.py
+#
+# Copyright (C) 2018 Kano Computing Ltd.
+# License: http://www.gnu.org/licenses/gpl-2.0.txt GNU GPL v2x
+#
+# Wrapper for when the monitor needs to be tested in a separate process to pytest
+#
+import sys
+import os
+sys.path.append(os.path.join(
+    os.path.dirname(os.path.realpath(__file__)), 'fixtures/mock_imports'
+))
+import kano_updater.monitor
+import sys
+test_cmd = sys.argv[1:]
+sys.exit(kano_updater.monitor.run(test_cmd))

tests/test_monitor.py

@@ -18,8 +18,12 @@ def run_monitor(mon_timeout, test_cmd):
 
     return rc
 
+def run_monitor_wrap(mon_timeout, test_cmd):
+    import subprocess
+    return subprocess.call(["./tests/monitor_wrap.py"]+test_cmd, shell=False)
 
-def test_return_code():
+
+def test_return_code(monitor_pid, apt):
     import os
     import random
     # When command returns in time,
@@ -29,7 +33,7 @@ def test_return_code():
     assert rc == expected_rc
 
 
-def test_return_timeout():
+def test_return_timeout(monitor_pid, apt):
     import os
     import random
     import kano_updater.return_codes
@@ -40,7 +44,7 @@ def test_return_timeout():
     assert rc == kano_updater.return_codes.RC.HANGED_INDEFINITELY 
 
 
-def test_forking():
+def test_forking(monitor_pid, apt):
     import os
     import random
     # When command takes longer than timeout but forks,
@@ -50,7 +54,7 @@ def test_forking():
     assert rc == expected_rc
 
 
-def test_signal():
+def test_signal(monitor_pid, apt):
     import os
     import random
     # When command takes longer than timeout but signals,
@@ -60,5 +64,34 @@ def test_signal():
     assert rc == expected_rc
 
 
+def test_no_monitor(monitor_pid, apt):
+    import os
+    import random
+    os.environ["MONITOR_PID"] = str(os.getpid())
+    # When MONITOR_PID is already set, don't execute monitor behavior
+
+    command_rc = random.randint(1, 20)
+    rc = run_monitor_wrap(5, ["./tests/monitor_stub.py", "10", str(command_rc)])
+    assert rc == command_rc  # would be HANGED_INDEFINITELY except that we are not monitoring
+
+
+def test_monitor_term(monitor_pid, apt):
+
+    import random
+    import subprocess
+    import time
+    import signal
+    # When we send a term signal to the monitor process, it sends it to the
+    # child process.
+    # Note that this test assumes that the monitor process correctly
+    # reports the child process exit code
+    command_rc = random.randint(1, 20)
+    proc = subprocess.Popen(["./tests/monitor_stub.py", "10", str(command_rc)])
+    time.sleep(2)
+    proc.terminate()
+    proc.wait()
+    rc = proc.returncode
+    assert rc == -signal.SIGTERM
+
 # TBD:
 #   - test gui mode