perf: replace mongosh ping with Python script for lightweight healthcheck

Author: FuryL

compose.yml

@@ -3,12 +3,15 @@ name: stoat
 services:
   # MongoDB: Database
   database:
-    image: docker.io/mongo
+    build: 
+      context: . 
+      dockerfile: mongo.Dockerfile
     restart: always
     volumes:
       - ./data/db:/data/db
+      - ./mongo_ping.py:/mongo_ping.py
     healthcheck:
-      test: echo 'db.runCommand("ping").ok' | mongosh localhost:27017/test --quiet
+      test: ["CMD", "python3", "/mongo_ping.py"]
       interval: 10s
       timeout: 10s
       retries: 5

mongo.Dockerfile

@@ -0,0 +1,6 @@
+FROM docker.io/mongo:latest
+
+# install Python3, pip, pymongo for low memory usage healthcheck
+RUN apt-get update && \
+    apt-get install -y python3 python3-pip python3-pymongo && \
+    rm -rf /var/lib/apt/lists/*

mongo_ping.py

@@ -0,0 +1,24 @@
+from pymongo import MongoClient
+from pymongo.errors import PyMongoError
+import sys
+import json
+
+try:
+    client = MongoClient(
+        "mongodb://localhost:27017",
+        connectTimeoutMS=3000,
+        serverSelectionTimeoutMS=5000,
+        socketTimeoutMS=5000,
+        directConnection=True,
+    )
+
+    client.admin.command("ping")
+    print(json.dumps({"ok": 1}))
+    sys.exit(0)
+
+except PyMongoError as e:
+    print(json.dumps({
+        "ok": 0,
+        "error": str(e)
+    }, ensure_ascii=False), file=sys.stderr)
+    sys.exit(1)