Add MariaDB HTTP readiness service

server.py

@@ -0,0 +1,79 @@
+import json
+import os
+from http import HTTPStatus
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+from urllib.parse import urlsplit
+
+import pymysql
+
+
+PORT = int(os.environ.get("PORT", "8080"))
+DB_CONFIG = {
+    "host": os.environ.get("DB_HOST", "127.0.0.1"),
+    "port": int(os.environ.get("DB_PORT", "3306")),
+    "database": os.environ.get("DB_NAME", "maria"),
+    "user": os.environ.get("DB_USER", ""),
+    "password": os.environ.get("DB_PASSWORD", ""),
+    "charset": "utf8mb4",
+    "connect_timeout": 3,
+    "read_timeout": 3,
+    "write_timeout": 3,
+    "autocommit": True,
+}
+
+
+def database_ready():
+    connection = None
+    cursor = None
+    try:
+        connection = pymysql.connect(**DB_CONFIG)
+        cursor = connection.cursor()
+        cursor.execute("SELECT 1")
+        return cursor.fetchone() == (1,)
+    except (pymysql.MySQLError, OSError):
+        return False
+    finally:
+        if cursor is not None:
+            cursor.close()
+        if connection is not None:
+            connection.close()
+
+
+class Handler(BaseHTTPRequestHandler):
+    server_version = "MariaDBCheck/1.0"
+    sys_version = ""
+
+    def send_json(self, status, payload):
+        body = json.dumps(payload, separators=(",", ":")).encode("utf-8")
+        self.send_response(status)
+        self.send_header("Content-Type", "application/json; charset=utf-8")
+        self.send_header("Content-Length", str(len(body)))
+        self.send_header("Cache-Control", "no-store")
+        self.end_headers()
+        self.wfile.write(body)
+
+    def do_GET(self):
+        path = urlsplit(self.path).path
+        if path == "/healthz":
+            self.send_json(HTTPStatus.OK, {"status": "ok"})
+            return
+
+        if path in ("/", "/readyz"):
+            ready = database_ready()
+            status = HTTPStatus.OK if ready else HTTPStatus.SERVICE_UNAVAILABLE
+            self.send_json(
+                status,
+                {
+                    "service": "maria-http",
+                    "status": "ready" if ready else "unavailable",
+                    "database": "connected" if ready else "unavailable",
+                },
+            )
+            return
+
+        self.send_json(HTTPStatus.NOT_FOUND, {"error": "not_found"})
+
+
+if __name__ == "__main__":
+    server = ThreadingHTTPServer(("0.0.0.0", PORT), Handler)
+    server.serve_forever()