I am not able to connect to gcloud sql from the nodejs app hosted in app engine

Question

I have a hosted node app and mysql on google cloud. I tried all possible ways to connect mysql from node but every time it throws this error.

    let pool;
    const createPool = async () => {
      pool = await mysql.createPool({
       //   host: "35.200.129.217",
    socketPath:"/cloudsql/idyllic-anvil-256103:asia-south1:database",
      user: "[email protected]",
      password: "pass",
      database: "db"
      });
    };
    createPool();

    app.get("/getnews", (request, response) => {
    createPool.query('SELECT * FROM db.mydb', function (err, result) {
        if (err) throw new Error(err)
        response.send(result);
    })
    });

Error:

    2019-10-19 16:33:40 default[20191019t215943]  Error: Error: connect ETIMEDOUT      at Query._callback (/srv/index.js:42:20)      at Query.Sequence.end (/srv/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)      at /srv/node_modules/mysql/lib/Pool.js:205:13      at Handshake.onConnect (/srv/node_modules/mysql/lib/Pool.js:58:9)      at Handshake.<anonymous> (/srv/node_modules/mysql/lib/Connection.js:525:10)      at Handshake._callback (/srv/node_modules/mysql/lib/Connection.js:491:16)      at Handshake.Sequence.end (/srv/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)      at Protocol.handleNetworkError (/srv/node_modules/mysql/lib/protocol/Protocol.js:369:14)      at PoolConnection.Connection._handleNetworkError (/srv/node_modules/mysql/lib/Connection.js:421:18)      at PoolConnection.Connection._handleConnectTimeout (/srv/node_modules/mysql/lib/Connection.js:417:8)
    2019-10-19 16:34:16 default[20191019t220300]  "GET / HTTP/1.1" 304
    2019-10-19 16:34:18 default[20191019t220300]  Server listening on port 8081...
    2019-10-19 16:34:18 default[20191019t220300]  Database connection was refused.
    2019-10-19 16:34:22 default[20191019t220300]  "GET /getnews HTTP/1.1" 502
    2019-10-19 16:34:22 default[20191019t220300]  /srv/index.js:42
    2019-10-19 16:34:22 default[20191019t220300]      if (err) throw new Error(err)
    2019-10-19 16:34:22 default[20191019t220300]               ^
    2019-10-19 16:34:22 default[20191019t220300]
    2019-10-19 16:34:23 default[20191019t220300]  Error: Error: connect ECONNREFUSED /cloudsql/idyllic-anvil-256103:asia-south1:database      at Query._callback (/srv/index.js:42:20)      at Query.Sequence.end (/srv/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)      at /srv/node_modules/mysql/lib/Pool.js:205:13      at Handshake.onConnect (/srv/node_modules/mysql/lib/Pool.js:58:9)      at Handshake.<anonymous> (/srv/node_modules/mysql/lib/Connection.js:525:10)      at Handshake._callback (/srv/node_modules/mysql/lib/Connection.js:491:16)      at Handshake.Sequence.end (/srv/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)      at Protocol.handleNetworkError `enter code here`(/srv/node_modules/mysql/lib/protocol/Protocol.js:369:14)      at PoolConnection.Connection._handleNetworkError (/srv/node_modules/mysql/lib/Connection.js:421:18)      at Socket.emit (events.js:198:13)

Answer 1

Make sure you follow the instructions at Connecting to Cloud SQL from App Engine. In particular, the following things are easy to miss:

• Make sure your service account connecting has the Cloud SQL Client IAM role, or the permissions listed on the page
• If using App Engine Flex, make sure you've spelled it correctly in your app.yaml

Finally, make sure to take a look at Managing Database Connections page. In particular, in the example you have above you are initializing a function with a name, and then calling query on that function. Instead, you should use the pool to do your queries:

let pool; // <---- This is the pool that `createPool` will set
const createPool = async () => {
  pool = await mysql.createPool({
    socketPath:"/cloudsql/idyllic-anvil-256103:asia-south1:database",
    user: "[email protected]", //<--- just FYI, this should be the database user, not the GCP account connecting
    password: "pass",
    database: "db"
  });
};
createPool(); // <----- This is where `pool` is actually created


// Now we can use the pool to query like this:
try {
  const stmt = 'INSERT INTO votes (time_cast, candidate) VALUES (?, ?)';
  // Pool.query automatically checks out, uses, and releases a connection
  // back into the pool, ensuring it is always returned successfully.
  await pool.query(stmt, [timestamp, team]);
} catch (err) {
  // If something goes wrong, handle the error in this section. This might
  // involve retrying or adjusting parameters depending on the situation.
  // ...
}