Add SIGTERM handling to geographic gatherer

[pnuu]

This PR adds SIGTERM handling to geographic gatherer.

After receiving the signal, the gatherer will wait until all active collections have been finished and then exit the program.

[pnuu]

Locally I have an issue with the tests never exiting. The tests pass, but then hang until CTRL+C:

======================================================== 14 passed, 22 warnings in 2.22s ========================================================
^CException ignored in: <module 'threading' from '/home/lahtinep/mambaforge/envs/py312/lib/python3.12/threading.py'>
Traceback (most recent call last):
  File "/home/lahtinep/mambaforge/envs/py312/lib/python3.12/threading.py", line 1624, in _shutdown
    lock.acquire()
KeyboardInterrupt: 
/home/lahtinep/mambaforge/envs/py312/lib/python3.12/site-packages/_pytest/pathlib.py:95: PytestWarning: (rm_rf) error removing /tmp/pytest-of-lahtinep/garbage-3a9a0511-3423-47e3-959b-19062ba25739
<class 'OSError'>: [Errno 39] Directory not empty: '/tmp/pytest-of-lahtinep/garbage-3a9a0511-3423-47e3-959b-19062ba25739'
  warnings.warn(

The actual functionality seems to work fine when running the main script. At least when there are no collecting going on, which I don't have an easy way to test.

[pnuu]

Running the actual script in terminal and killing the process:

$ geographic_gatherer.py -p 40000 -n false -i 127.0.0.1:40001 /tmp/geographic_gatherer.ini 
/home/lahtinep/mambaforge/envs/py312/bin/geographic_gatherer.py:4: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
  __import__('pkg_resources').require('pytroll-collectors==0.16.0+0.gacc2631.dirty')
Setting timezone to UTC
[INFO: 2024-11-12 08:49:33 : posttroll.backends.zmq.publisher] Publisher for tcp://*:40000 started on port 40000.
[INFO: 2024-11-12 08:49:33 : posttroll.backends.zmq.subscriber] Subscriber adding address tcp://127.0.0.1:40001 with topics ['pytroll://ears/mersi/fy-3d/segment']
[INFO: 2024-11-12 08:49:47 : pytroll_collectors.geographic_gatherer] Caught SIGTERM, shutting down when all collections are finished.
[INFO: 2024-11-12 08:49:47 : pytroll_collectors.geographic_gatherer] Shutting down...
[INFO: 2024-11-12 08:49:47 : pytroll_collectors.geographic_gatherer] Ending the gathering of granules...
[INFO: 2024-11-12 08:49:47 : geographic_gatherer] GeographicGatherer has stopped.

[pnuu]

In 962e875 I mock the trigger creation. I think I need to create a more involved mock or fake trigger creation with collectors to simulate the structure so that the checks in _keep_running() are there.

[codecov]

Codecov Report

Attention: Patch coverage is 88.46154% with 6 lines in your changes missing coverage. Please review.

Project coverage is 91.78%. Comparing base (3409378) to head (e866900).
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
...troll_collectors/tests/test_geographic_gatherer.py	88.46%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #157      +/-   ##
==========================================
- Coverage   91.82%   91.78%   -0.05%     
==========================================
  Files          28       28              
  Lines        3953     4005      +52     
==========================================
+ Hits         3630     3676      +46     
- Misses        323      329       +6     

Flag	Coverage Δ
unittests	91.78% <88.46%> (-0.05%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[coveralls]

Pull Request Test Coverage Report for Build 11817159508

Details

• 52 of 71 (73.24%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.3%) to 90.775%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pytroll_collectors/tests/test_geographic_gatherer.py	46	52	88.46%
pytroll_collectors/geographic_gatherer.py	6	19	31.58%

Totals
Change from base Build 11815718287:	-0.3%
Covered Lines:	4113
Relevant Lines:	4531

---

💛 - Coveralls

[pnuu]

With e866900 I think the new feature is "fully" tested.

[mraspaud]

LGTM!