fix(base): Add python metrics to prometheus exporter

ref: #436

app/centurion/celery.py

@@ -0,0 +1,78 @@
+import logging
+import os
+
+from django.conf import settings
+
+from celery import Celery, signals
+
+from pathlib import Path
+
+from prometheus_client import multiprocess, start_http_server, REGISTRY
+
+logger = logging.getLogger(__name__)
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'centurion.settings')
+
+worker = Celery('app')
+
+worker.config_from_object(f'django.conf:settings', namespace='CELERY')
+
+worker.autodiscover_tasks()
+
+
+@worker.task(bind=True, ignore_result=True)
+def debug_task(self):
+    print(f'Request: {self!r}')
+
+
+
+@signals.worker_ready.connect()
+def setup_prometheus(**kwargs):
+
+    if not getattr(settings, 'METRICS_ENABLED', False):
+        return
+
+    proc_path = None
+
+    try:
+        proc_path = os.environ["PROMETHEUS_MULTIPROC_DIR"]
+    except:
+        pass
+
+
+    if not proc_path:
+
+        os.environ["PROMETHEUS_MULTIPROC_DIR"] = settings.METRICS_MULTIPROC_DIR
+
+        proc_path = os.environ["PROMETHEUS_MULTIPROC_DIR"]
+
+
+    logger.info(f'Setting up prometheus metrics HTTP server on port {str(settings.METRICS_EXPORT_PORT)}.')
+
+    multiproc_folder_path = _setup_multiproc_folder()
+
+    registry = REGISTRY
+
+    logger.info(f'Setting up prometheus metrics directory.')
+
+    multiprocess.MultiProcessCollector(registry, path=multiproc_folder_path)
+
+    logger.info(f'Starting prometheus metrics server.')
+
+    start_http_server( settings.METRICS_EXPORT_PORT, registry=registry)
+
+    logger.info(f'Starting prometheus serving on port {str(settings.METRICS_EXPORT_PORT)}.')
+
+
+
+def _setup_multiproc_folder():
+
+    coordination_dir = Path(os.environ["PROMETHEUS_MULTIPROC_DIR"])
+
+    coordination_dir.mkdir(parents=True, exist_ok=True)
+
+    for filepath in coordination_dir.glob("*.db"):
+
+        filepath.unlink()
+
+    return coordination_dir

includes/etc/gunicorn.conf.py

@@ -5,7 +5,7 @@ from pathlib import Path
 
 from django.conf import settings
 
-from prometheus_client import CollectorRegistry, multiprocess, start_http_server
+from prometheus_client import multiprocess, start_http_server, REGISTRY
 
 
 
@@ -50,7 +50,7 @@ def when_ready(_):
 
     multiproc_folder_path = _setup_multiproc_folder()
 
-    registry = CollectorRegistry()
+    registry = REGISTRY
 
     logger.info(f'Setting up prometheus metrics directory.')