Troubleshooting PostgreSQL Connection Issues

Sounds like you’re in a bit of a pickle! Here are a few things you can check to hopefully get your Node.js app talking to your PostgreSQL database:

1. Check the Connection String

Make sure your connection string is formatted correctly. It should look something like this:

const connectionString = 'postgresql://username:password@localhost:5432/database_name';

Double-check the username, password, and database name! Typo here can be sneaky.

2. PostgreSQL Server Status

Even if you think the server is running, it might be worth restarting it just to be sure. You can usually do this with:

sudo service postgresql restart

3. Port Listening

Confirm that PostgreSQL is actually listening on port 5432. Run this command:

netstat -an | grep 5432

If nothing shows up, it might not be running on the expected port.

4. Firewall Rules

Firewalls can be tricky! Make sure your firewall isn’t blocking port 5432. If you’re on Linux, you can check with:

sudo ufw status

If it’s active, you might need to allow connections:

sudo ufw allow 5432

5. Environment Issues

If you’re using Docker, remember that the default localhost in your Node.js app won’t point to the PostgreSQL container. You usually need to use the service name or the IP of the container.

6. Connection Pooling & Options

Sometimes tweaking connection options like timeouts can help. If you’re using `pg-promise`, make sure you set up your connection like this:

const pgp = require('pg-promise')();
const db = pgp({
    host: 'localhost',
    port: 5432,
    database: 'database_name',
    user: 'username',
    password: 'password',
    // Optional timeout
    connectTimeout: 3000, // 3 seconds
});
    

7. Error Logging

Add error logging to your connection code to see if there’s more info about the “Connection refused” error:

db.connect()
    .then(obj => {
        obj.done(); // success, release the connection;
    })
    .catch(error => {
        console.log('ERROR:', error.message || error);
    });
    

Hopefully, one of these tips helps you out! Keep at it, and don’t hesitate to reach out if you hit more bumps along the way. Good luck!