[supervisor] Add patch to prevent 'supervisorctl start' command from …

…hanging if system time has rolled backward (#1311)

* Add patch to prevent 'supervisorctl start' command from hanging if system time has rolled backward

* Also add unit tests for clock rollback scenarios

.gitignore

@@ -35,6 +35,7 @@ src/sonic-device-data/src/device/
 src/sonic-device-data/src/debian/
 src/supervisor/*
 !src/supervisor/Makefile
+!src/supervisor/patch/
 src/thrift/*
 !src/thrift/Makefile
 

rules/supervisor.mk

@@ -1,5 +1,9 @@
 # supervisor package
 
-SUPERVISOR = python-supervisor_3.3.2-1_all.deb
+SUPERVISOR_VERSION = 3.3.2
+
+export SUPERVISOR_VERSION
+
+SUPERVISOR = python-supervisor_$(SUPERVISOR_VERSION)-1_all.deb
 $(SUPERVISOR)_SRC_PATH = $(SRC_PATH)/supervisor
 SONIC_MAKE_DEBS += $(SUPERVISOR)

src/supervisor/Makefile

@@ -2,7 +2,7 @@
 SHELL = /bin/bash
 .SHELLFLAGS += -e
 
-MAIN_TARGET = python-supervisor_3.3.2-1_all.deb
+MAIN_TARGET = python-supervisor_$(SUPERVISOR_VERSION)-1_all.deb
 
 $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
 	# Remove any stale files
@@ -11,7 +11,15 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
 	# Clone supervisor repo
 	git clone https://github.com/Supervisor/supervisor.git
 	pushd ./supervisor
-	git checkout -f 3.3.2
+
+	# Reset HEAD to the commit of the proper tag
+	# NOTE: Using "git checkout <tag_name>" here detaches our HEAD,
+	# which stg doesn't like, so we use this method instead
+	git reset --hard $(SUPERVISOR_VERSION)
+
+	# Apply patches
+	stg init
+	stg import -s ../patch/series
 
 	# Build Python and Debian package
 	python setup.py --command-packages=stdeb.command bdist_deb

src/supervisor/patch/0001-Prevent-excessive-hanging-delays-in-process-state-tr.patch

@@ -0,0 +1,83 @@
+From bac496af4c2051b3c15038e06533f9094b1c3604 Mon Sep 17 00:00:00 2001
+From: Joe LeVeque <jolevequ@microsoft.com>
+Date: Tue, 16 Jan 2018 20:42:13 +0000
+Subject: [PATCH 1/2] Prevent excessive hanging/delays in process state
+ transitions if the system time rolls backward
+
+---
+ supervisor/process.py | 32 ++++++++++++++++++++++++++++++++
+ 1 file changed, 32 insertions(+)
+
+diff --git a/supervisor/process.py b/supervisor/process.py
+index f9ddcd9..216372f 100644
+--- a/supervisor/process.py
++++ b/supervisor/process.py
+@@ -357,6 +357,12 @@ class Subprocess:
+         """ Log a 'waiting for x to stop' message with throttling. """
+         if self.state == ProcessStates.STOPPING:
+             now = time.time()
++
++            # If the system clock has moved backward, reset
++            # self.laststopreport to current system time
++            if now < self.laststopreport:
++                self.laststopreport = now;
++
+             if now > (self.laststopreport + 2): # every 2 seconds
+                 self.config.options.logger.info(
+                     'waiting for %s to stop' % self.config.name)
+@@ -604,12 +610,27 @@ class Subprocess:
+                     # STOPPED -> STARTING
+                     self.spawn()
+             elif state == ProcessStates.BACKOFF:
++                if self.delay > 0 and now < self.delay - self.backoff:
++                    # The system clock appears to have moved backward
++                    # Reset self.delay accordingly
++                    self.delay = now + self.backoff
++
+                 if self.backoff <= self.config.startretries:
+                     if now > self.delay:
+                         # BACKOFF -> STARTING
+                         self.spawn()
+
+         if state == ProcessStates.STARTING:
++            if now < self.laststart:
++                # The system clock appears to have moved backward
++                # Reset self.laststart to current system time
++                self.laststart = now;
++
++            if self.delay > 0 and now < self.delay - self.config.startsecs:
++                # The system clock appears to have moved backward
++                # Reset self.delay accordingly
++                self.delay = now + self.config.startsecs
++
+             if now - self.laststart > self.config.startsecs:
+                 # STARTING -> RUNNING if the proc has started
+                 # successfully and it has stayed up for at least
+@@ -633,6 +654,11 @@ class Subprocess:
+                 logger.info('gave up: %s %s' % (self.config.name, msg))
+
+         elif state == ProcessStates.STOPPING:
++            if self.delay > 0 and now < self.delay - self.config.stopwaitsecs:
++                # The system clock appears to have moved backward
++                # Reset self.delay accordingly
++                self.delay = now + self.config.stopwaitsecs
++
+             time_left = self.delay - now
+             if time_left <= 0:
+                 # kill processes which are taking too long to stop with a final
+@@ -805,6 +831,12 @@ class EventListenerPool(ProcessGroupBase):
+         if dispatch_capable:
+             if self.dispatch_throttle:
+                 now = time.time()
++
++                # If the system clock has moved backward, reset
++                # self.last_dispatch to current system time
++                if now < self.last_dispatch:
++                    self.last_dispatch = now;
++
+                 if now - self.last_dispatch < self.dispatch_throttle:
+                     return
+             self.dispatch()
+-- 
+2.1.4
+

src/supervisor/patch/0002-Add-unit-test-cases-to-ensure-state-transitions-work.patch

@@ -0,0 +1,184 @@
+From 43b6f3ee93593f666af2c6a7af897bf3b5ee762d Mon Sep 17 00:00:00 2001
+From: Joe LeVeque <jolevequ@microsoft.com>
+Date: Wed, 17 Jan 2018 22:27:56 +0000
+Subject: [PATCH 2/2] Add unit test cases to ensure state transitions work if
+ system time has rolled backward
+
+---
+ supervisor/tests/test_process.py | 146 +++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 146 insertions(+)
+
+diff --git a/supervisor/tests/test_process.py b/supervisor/tests/test_process.py
+index 7f9bab2..ea16315 100644
+--- a/supervisor/tests/test_process.py
++++ b/supervisor/tests/test_process.py
+@@ -736,6 +736,40 @@ class SubprocessTests(unittest.TestCase):
+         instance.stop_report()
+         self.assertEqual(len(options.logger.data), 1) # throttled
+
++    def test_stop_report_laststopreport_in_future(self):
++        future_time = time.time() + 3600 # 1 hour into the future
++        options = DummyOptions()
++        config = DummyPConfig(options, 'test', '/test')
++        instance = self._makeOne(config)
++        instance.pid = 11
++        dispatcher = DummyDispatcher(writable=True)
++        instance.dispatchers = {'foo':dispatcher}
++        from supervisor.states import ProcessStates
++        instance.state = ProcessStates.STOPPING
++        instance.laststopreport = future_time
++
++        # This iteration of stop_report() should reset instance.laststopreport
++        # to the current time
++        instance.stop_report()
++
++        # No logging should have taken place
++        self.assertEqual(len(options.logger.data), 0)
++
++        # Ensure instance.laststopreport has rolled backward
++        self.assertTrue(instance.laststopreport < future_time)
++
++        # Sleep for 2 seconds
++        time.sleep(2)
++
++        # This iteration of stop_report() should actaully trigger the report
++        instance.stop_report()
++
++        self.assertEqual(len(options.logger.data), 1)
++        self.assertEqual(options.logger.data[0], 'waiting for test to stop')
++        self.assertNotEqual(instance.laststopreport, 0)
++        instance.stop_report()
++        self.assertEqual(len(options.logger.data), 1) # throttled
++
+     def test_give_up(self):
+         options = DummyOptions()
+         config = DummyPConfig(options, 'test', '/test')
+@@ -1402,6 +1436,92 @@ class SubprocessTests(unittest.TestCase):
+         event = L[0]
+         self.assertEqual(event.__class__, events.ProcessStateRunningEvent)
+
++    def test_transition_starting_to_running_laststart_in_future(self):
++        from supervisor import events
++        L = []
++        events.subscribe(events.ProcessStateEvent, lambda x: L.append(x))
++        from supervisor.states import ProcessStates
++
++        future_time = time.time() + 3600 # 1 hour into the future
++        options = DummyOptions()
++        test_startsecs = 2
++
++        # this should go from STARTING to RUNNING via transition()
++        pconfig = DummyPConfig(options, 'process', 'process','/bin/process',
++                               startsecs=test_startsecs)
++        process = self._makeOne(pconfig)
++        process.backoff = 1
++        process.delay = 1
++        process.system_stop = False
++        process.laststart = future_time
++        process.pid = 1
++        process.stdout_buffer = 'abc'
++        process.stderr_buffer = 'def'
++        process.state = ProcessStates.STARTING
++
++        # This iteration of transition() should reset process.laststart
++        # to the current time
++        process.transition()
++
++        # Process state should still be STARTING
++        self.assertEqual(process.state, ProcessStates.STARTING)
++
++        # Ensure process.laststart has rolled backward
++        self.assertTrue(process.laststart < future_time)
++
++        # Sleep for (startsecs + 1)
++        time.sleep(test_startsecs + 1)
++
++        # This iteration of transition() should actaully trigger the state
++        # transition to RUNNING
++        process.transition()
++
++        # this implies RUNNING
++        self.assertEqual(process.backoff, 0)
++        self.assertEqual(process.delay, 0)
++        self.assertFalse(process.system_stop)
++        self.assertEqual(process.state, ProcessStates.RUNNING)
++        self.assertEqual(options.logger.data[0],
++                         'success: process entered RUNNING state, process has '
++                         'stayed up for > than {} seconds (startsecs)'.format(test_startsecs))
++        self.assertEqual(len(L), 1)
++        event = L[0]
++        self.assertEqual(event.__class__, events.ProcessStateRunningEvent)
++
++    def test_transition_backoff_to_starting_delay_in_future(self):
++        from supervisor import events
++        L = []
++        events.subscribe(events.ProcessStateEvent, lambda x: L.append(x))
++        from supervisor.states import ProcessStates, SupervisorStates
++
++        future_time = time.time() + 3600 # 1 hour into the future
++        options = DummyOptions()
++
++        pconfig = DummyPConfig(options, 'process', 'process','/bin/process')
++        process = self._makeOne(pconfig)
++        process.laststart = 1
++        process.delay = future_time
++        process.backoff = 0
++        process.state = ProcessStates.BACKOFF
++
++        # This iteration of transition() should reset process.delay
++        # to the current time
++        process.transition()
++
++        # Process state should still be BACKOFF
++        self.assertEqual(process.state, ProcessStates.BACKOFF)
++
++        # Ensure process.delay has rolled backward
++        self.assertTrue(process.delay < future_time)
++
++        # This iteration of transition() should actaully trigger the state
++        # transition to STARTING
++        process.transition()
++
++        self.assertEqual(process.state, ProcessStates.STARTING)
++        self.assertEqual(len(L), 1)
++        self.assertEqual(L[0].__class__, events.ProcessStateStartingEvent)
++
+     def test_transition_backoff_to_fatal(self):
+         from supervisor import events
+         L = []
+@@ -2033,6 +2153,32 @@ class EventListenerPoolTests(ProcessGroupBaseTests):
+         self.assertEqual(process1.listener_state, EventListenerStates.BUSY)
+         self.assertEqual(process1.event, event)
+
++    def test_transition_event_proc_running_with_dispatch_throttle_last_dispatch_in_future(self):
++        future_time = time.time() + 3600 # 1 hour into the future
++        options = DummyOptions()
++        from supervisor.states import ProcessStates
++        pconfig1 = DummyPConfig(options, 'process1', 'process1','/bin/process1')
++        process1 = DummyProcess(pconfig1, state=ProcessStates.RUNNING)
++        gconfig = DummyPGroupConfig(options, pconfigs=[pconfig1])
++        pool = self._makeOne(gconfig)
++        pool.dispatch_throttle = 5
++        pool.last_dispatch = future_time
++        pool.processes = {'process1': process1}
++        event = DummyEvent()
++        from supervisor.states import EventListenerStates
++        process1.listener_state = EventListenerStates.READY
++        class DummyGroup:
++            config = gconfig
++        process1.group = DummyGroup
++        pool._acceptEvent(event)
++        pool.transition()
++
++        self.assertEqual(process1.transitioned, True)
++        self.assertEqual(pool.event_buffer, [event]) # not popped
++
++        # Ensure pool.last_dispatch has been rolled backward
++        self.assertTrue(pool.last_dispatch < future_time)
++
+     def test__dispatchEvent_notready(self):
+         options = DummyOptions()
+         from supervisor.states import ProcessStates
+-- 
+2.1.4
+

src/supervisor/patch/series

@@ -0,0 +1,2 @@
+0001-Prevent-excessive-hanging-delays-in-process-state-tr.patch
+0002-Add-unit-test-cases-to-ensure-state-transitions-work.patch