Rewrote the Flask server into a FastAPI one that has Prometheus metrics and connects to a database

src/main.py

@@ -0,0 +1,113 @@
+from fastapi import FastAPI, Depends, HTTPException, Response, Request
+import uvicorn
+from github_api import find_package_version_with_tag as find_package_version_with_tag_github
+from dockerhub_api import find_package_version_with_tag as find_package_version_with_tag_dockerhub
+import uvicorn
+from contextlib import asynccontextmanager
+from db import get_db, create_connection_pool, close_connection_pool
+import logging
+from send_notification import send_notification
+from metrics_server import REQUEST_COUNTER
+import asyncio
+
+logger = logging.getLogger(__name__)
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+	logger.info("Starting application...")
+
+	logger.info("Creating MySQL connection pool...")
+	create_connection_pool()
+
+	yield
+	logger.info("Closing MySQL connection pool...")
+	close_connection_pool()
+
+api = FastAPI(
+		title="Docker Repository Query",
+		description="Queries Dockerhub and GHCR for new docker images",
+		version="1.0.0",
+		lifespan=lifespan
+)
+
+@api.middleware("http")
+async def prometheus_middleware(request: Request, call_next):
+	try:
+		response = await call_next(request)
+		status = response.status_code
+	except Exception:
+		status = 500
+		raise
+	finally:
+		REQUEST_COUNTER.labels(request.method, request.url.path, status).inc()
+	return response
+
+
+@api.get("/health")
+def return_health():
+	return Response(status_code=200)
+
+
+@api.get("/suwayomi")
+def handle_suwayomi(
+		request: Request,
+		db = Depends(get_db)
+		):
+
+	try:
+		logger.info("Suwayomi handler invoked")
+		latest_online_version = find_package_version_with_tag_github("Suwayomi", "tachidesk", "stable")
+
+		cursor = db.cursor()
+		cursor.execute("SELECT latest_version FROM docker_repositories WHERE app='suwayomi'")
+		local_state = cursor.fetchone()
+
+		if local_state and latest_online_version != local_state[0]:
+			cursor.execute ("UPDATE docker_repositories SET latest_version=%s WHERE app='suwayomi'",
+				    (latest_online_version,))
+			db.commit()
+			logger.info("New Suwayomi version has been found")
+			send_notification("New Suwayomi version has been found")
+			return Response(status_code=200)
+		return Response(status_code=204)
+	except Exception as e:
+		raise HTTPException(status_code=500, detail=str(e))
+
+
+
+@api.get("/pihole")
+def handle_pihole(
+		request: Request,
+		db = Depends(get_db)
+		):
+	try:
+		logger.info("Pi-hole handler invoked")
+		latest_online_version = find_package_version_with_tag_dockerhub("pihole/pihole", "latest")
+		
+		cursor = db.cursor()
+		cursor.execute("SELECT latest_version FROM docker_repositories WHERE app='pihole'")
+		local_state = cursor.fetchone()
+
+		if local_state and latest_online_version != local_state[0]:
+			cursor.execute ("UPDATE docker_repositories SET latest_version=%s WHERE app='pihole'",
+					(latest_online_version,))
+			db.commit()
+			logger.info("New Pi-hole version has been found")
+			send_notification("New Pi-hole version has been found")
+			return Response(status_code=200)
+		return Response(status_code=204)
+	except Exception as e:
+		raise HTTPException(status_code=500, detail=str(e))
+
+
+async def start_servers():
+	config_main = uvicorn.Config("main:api", host="0.0.0.0", port=5000, log_level="info")
+	config_metrics = uvicorn.Config("metrics_server:metrics_api", host="0.0.0.0", port=9000, log_level="info")
+
+	server_main = uvicorn.Server(config_main)
+	server_metrics = uvicorn.Server(config_metrics)
+
+	await asyncio.gather(server_main.serve(), server_metrics.serve())
+
+if __name__ == "__main__":
+	asyncio.run(start_servers())