From 15d58762d5ceae2a97b3cd00f7ff88d9d495dd6b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= <sybren@stuvel.eu>
Date: Fri, 20 Oct 2017 13:30:52 +0200
Subject: [PATCH] Allow shutting down the worker from the Manager.
When the worker receives the "shutdown" state it'll cleanly shut down, and
eventually go to "offline" state.
---
CHANGELOG.md | 2 ++
flamenco_worker/cli.py | 19 +++++++++------
flamenco_worker/worker.py | 23 +++++++++++++++++--
.../systemd/flamenco-worker.service | 2 +-
4 files changed, 36 insertions(+), 10 deletions(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe0e1d3d..b90e057d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,8 @@ changed functionality, fixed bugs).
- Fixed sending task status updates after the task may no longer be run.
- Worker goes to sleep when receiving signal USR1 and wakes up after signal USR2.
This is only supported on POSIX platforms that have those signals.
+- Worker can be told to shut down by the Manager. The environment (for example systemd
+ on Linux) is responsible for restarting Flamenco Worker after such a shutdown.
## Version 2.0.8 (released 2017-09-07)
diff --git a/flamenco_worker/cli.py b/flamenco_worker/cli.py
index d1c3b8e2..4705a991 100644
--- a/flamenco_worker/cli.py
+++ b/flamenco_worker/cli.py
@@ -136,13 +136,7 @@ def main():
asyncio.ensure_future(tuqueue.work(loop=loop))
mir_work_task = asyncio.ensure_future(mir.work())
- try:
- loop.run_until_complete(fworker.startup())
- fworker.mainloop()
- except worker.UnableToRegisterError:
- # The worker will have logged something, we'll just shut down cleanly.
- pass
- except KeyboardInterrupt:
+ def do_clean_shutdown():
shutdown_future.cancel()
mir_work_task.cancel()
try:
@@ -158,8 +152,19 @@ def main():
loop.stop()
loop.run_until_complete(stop_loop())
+
+ try:
+ loop.run_until_complete(fworker.startup())
+ fworker.mainloop()
+ except worker.UnableToRegisterError:
+ # The worker will have logged something, we'll just shut down cleanly.
+ pass
+ except KeyboardInterrupt:
+ do_clean_shutdown()
except:
log.exception('Uncaught exception!')
+ else:
+ do_clean_shutdown()
# Report on the asyncio task status
if args.verbose:
diff --git a/flamenco_worker/worker.py b/flamenco_worker/worker.py
index dcaf10b2..b7ee3abb 100644
--- a/flamenco_worker/worker.py
+++ b/flamenco_worker/worker.py
@@ -578,6 +578,7 @@ class FlamencoWorker:
status_change_handlers = {
'asleep': self.go_to_state_asleep,
'awake': self.go_to_state_awake,
+ 'shutdown': self.go_to_state_shutdown,
}
try:
@@ -588,7 +589,7 @@ class FlamencoWorker:
handler()
- def ack_status_change(self, new_status: str):
+ def ack_status_change(self, new_status: str) -> asyncio.Task:
"""Confirm that we're now in a certain state.
This ACK can be given without a request from the server, for example to support
@@ -597,7 +598,7 @@ class FlamencoWorker:
try:
post = self.manager.post('/ack-status-change/%s' % new_status, loop=self.loop)
- self.loop.create_task(post)
+ return self.loop.create_task(post)
except Exception:
self._log.exception('unable to notify Manager')
@@ -620,6 +621,24 @@ class FlamencoWorker:
self.schedule_fetch_task(3)
self.ack_status_change('awake')
+ def go_to_state_shutdown(self):
+ """Shuts down the Flamenco Worker.
+
+ Whether it comes back up depends on the environment. For example,
+ using systemd on Linux with Restart=always will do this.
+ """
+
+ self._log.info('Shutting down by request of the Flamenco Manager')
+ self.state = WorkerState.SHUTTING_DOWN
+
+ # Ack the status change before doing the actual shutdown.
+ def stop_main_loop(*args):
+ self._log.debug('Stopping main loop (%r)', args)
+ self.loop.stop()
+
+ post_task = self.ack_status_change('shutdown')
+ post_task.add_done_callback(stop_main_loop)
+
def stop_sleeping(self):
"""Stops the asyncio task for sleeping."""
if self.sleeping_task is None or self.sleeping_task.done():
diff --git a/system-integration/systemd/flamenco-worker.service b/system-integration/systemd/flamenco-worker.service
index 998cd0d3..7c42d220 100644
--- a/system-integration/systemd/flamenco-worker.service
+++ b/system-integration/systemd/flamenco-worker.service
@@ -15,7 +15,7 @@ WorkingDirectory=/shared/bin/flamenco-worker
User=guest
Group=guest
-RestartPreventExitStatus=0 SIGUSR1 SIGUSR2
+RestartPreventExitStatus=SIGUSR1 SIGUSR2
Restart=always
RestartSec=1s
--
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