fix(gunicorn): respect GUNICORN_KEEP_ALIVE and GUNICORN_CMD_ARGS

pyproject.toml

@@ -16,7 +16,7 @@ optional-dependencies = { test-tools = [
     "drf-spectacular (>=0.28.0,<1)",
     "drf-writable-nested",
     "environs (<16)",
-    "gunicorn (>=19.1)",
+    "gunicorn (>=23)",
     "opentelemetry-instrumentation-django (>=0.46b0,<1)",
     "opentelemetry-instrumentation-psycopg2 (>=0.46b0,<1)",
     "opentelemetry-instrumentation-redis (>=0.46b0,<1)",

src/common/gunicorn/utils.py

@@ -23,6 +23,7 @@
     "accesslog": env.str("ACCESS_LOG_LOCATION", os.devnull),
     "bind": "0.0.0.0:8000",
     "config": "python:common.gunicorn.conf",
+    "keepalive": env.int("GUNICORN_KEEP_ALIVE", 2),
     "logger_class": "common.gunicorn.logging.GunicornJsonCapableLogger",
     "statsd_prefix": "flagsmith.api",
     "threads": env.int("GUNICORN_THREADS", 1),
@@ -41,9 +42,19 @@ def __init__(self, options: dict[str, Any] | None) -> None:
 
     def load_config(self) -> None:
         cfg_settings = self.cfg.settings
+        env_args = self.cfg.parser().parse_args(self.cfg.get_cmd_args_from_env())
+        env_options = {
+            key: value
+            for key, value in vars(env_args).items()
+            if key != "args" and value is not None
+        }
         options_items = (
             (key, value)
-            for key, value in {**GUNICORN_FLAGSMITH_DEFAULTS, **self.options}.items()
+            for key, value in {
+                **GUNICORN_FLAGSMITH_DEFAULTS,
+                **env_options,
+                **self.options,
+            }.items()
             if key in cfg_settings
         )
         for key, value in options_items:

tests/unit/common/gunicorn/test_utils.py

@@ -2,11 +2,14 @@
 import signal
 import threading
 import time
+from collections.abc import Generator
+from importlib import reload
 
 import pytest
 from drf_spectacular.generators import EndpointEnumerator
 from pytest_mock import MockerFixture
 
+import common.gunicorn.utils
 from common.gunicorn.utils import (
     DjangoWSGIApplication,
     get_route_template,
@@ -34,9 +37,72 @@ def test_django_wsgi_application__defaults__expected_config(
         == "common.gunicorn.logging.GunicornJsonCapableLogger"
     )
     assert settings["config"].value == "python:common.gunicorn.conf"
+    assert settings["keepalive"].value == 2
+    assert settings["threads"].value == 1
+    assert settings["timeout"].value == 30
+    assert settings["workers"].value == 1
     assert app.load_wsgiapp() == wsgi_handler_mock
 
 
+@pytest.fixture
+def reload_gunicorn_utils() -> Generator[None, None, None]:
+    yield
+    reload(common.gunicorn.utils)
+
+
+@pytest.mark.usefixtures("reload_gunicorn_utils")
+def test_django_wsgi_application__env_vars_set__expected_config(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    # Given
+    monkeypatch.setenv("GUNICORN_KEEP_ALIVE", "65")
+    monkeypatch.setenv("GUNICORN_THREADS", "2")
+    monkeypatch.setenv("GUNICORN_TIMEOUT", "60")
+    monkeypatch.setenv("GUNICORN_WORKERS", "3")
+    utils = reload(common.gunicorn.utils)
+
+    # When
+    app = utils.DjangoWSGIApplication({})
+
+    # Then
+    settings = app.cfg.settings
+    assert settings["keepalive"].value == 65
+    assert settings["threads"].value == 2
+    assert settings["timeout"].value == 60
+    assert settings["workers"].value == 3
+
+
+def test_django_wsgi_application__gunicorn_cmd_args_set__overrides_defaults(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    # Given
+    monkeypatch.setenv("GUNICORN_CMD_ARGS", "--keep-alive 65 --workers 4")
+
+    # When
+    app = DjangoWSGIApplication({})
+
+    # Then
+    settings = app.cfg.settings
+    assert settings["keepalive"].value == 65
+    assert settings["workers"].value == 4
+    assert settings["config"].value == "python:common.gunicorn.conf"
+
+
+def test_django_wsgi_application__gunicorn_cmd_args_and_options_set__options_take_precedence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    # Given
+    monkeypatch.setenv("GUNICORN_CMD_ARGS", "--keep-alive 65 --workers 4")
+
+    # When
+    app = DjangoWSGIApplication({"keepalive": 10})
+
+    # Then
+    settings = app.cfg.settings
+    assert settings["keepalive"].value == 10
+    assert settings["workers"].value == 4
+
+
 def test_run_server__default_config_file__runs_expected(
     unused_tcp_port: int,
     mocker: MockerFixture,