feat: start celery worker programmatically (#2988)

### Description

Allow us to be more flexible with the option passed the celery worker,
for example, to change the logging level.

Dockerfile

@@ -201,14 +201,7 @@ RUN --mount=type=cache,target=/root/.cache/pip \
 USER ${UID}:${GID}
 WORKDIR /app
 
-CMD ["/usr/local/bin/celery", "worker", \
-    "--app=libretime_worker.tasks:worker", \
-    "--config=libretime_worker.config", \
-    "--beat", \
-    "--time-limit=1800", \
-    "--concurrency=1", \
-    "--loglevel=info"]
-
+CMD ["/usr/local/bin/libretime-worker"]
 ARG LIBRETIME_VERSION
 ENV LIBRETIME_VERSION=$LIBRETIME_VERSION
 

worker/install/systemd/libretime-worker.service

@@ -22,14 +22,7 @@ Environment=LIBRETIME_CONFIG_FILEPATH=@@CONFIG_FILEPATH@@
 Environment=LIBRETIME_LOG_FILEPATH=@@LOG_DIR@@/worker.log
 WorkingDirectory=@@WORKING_DIR@@/worker
 
-ExecStart=/usr/bin/sh -c '@@VENV_DIR@@/bin/celery worker \
-    --app=libretime_worker.tasks:worker \
-    --config=libretime_worker.config \
-    --beat \
-    --time-limit=1800 \
-    --concurrency=1 \
-    --loglevel=INFO \
-    --logfile=$LIBRETIME_LOG_FILEPATH'
+ExecStart=/usr/local/bin/libretime-worker
 Restart=always
 
 User=libretime

worker/libretime_worker/main.py

@@ -0,0 +1,28 @@
+from pathlib import Path
+from typing import Optional
+
+import click
+from libretime_shared.cli import cli_logging_options
+from libretime_shared.config import DEFAULT_ENV_PREFIX
+
+from .config import __name__ as config_module
+from .tasks import worker
+
+
+@click.command(context_settings={"auto_envvar_prefix": DEFAULT_ENV_PREFIX})
+@cli_logging_options()
+def cli(log_level: str, log_filepath: Optional[Path]):
+    """
+    Run celery.
+    """
+    args = [
+        f"--config={config_module}",
+        "--beat",
+        "--time-limit=1800",
+        "--concurrency=1",
+        f"--loglevel={log_level}",
+    ]
+    if log_filepath is not None:
+        args.append(f"--logfile={log_filepath}")
+
+    worker.worker_main(args)

worker/setup.py

@@ -15,6 +15,11 @@ setup(
     },
     license="MIT",
     packages=find_packages(exclude=["*tests*", "*fixtures*"]),
+    entry_points={
+        "console_scripts": [
+            "libretime-worker=libretime_worker.main:cli",
+        ]
+    },
     python_requires=">=3.8",
     install_requires=[
         "celery==4.4.7",