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Connect Hyperdrive to a Fly Postgres database instance.

This example shows you how to connect Hyperdrive to a Fly Postgres database instance.

1. Allow Hyperdrive access

You can connect Hyperdrive to any existing Fly database by:

  1. Allocating a public IP address to your Fly database instance
  2. Configuring an external service
  3. Deploying the configuration
  4. Obtain the connection string, which is used to connect the database to Hyperdrive.

  1. Run the following command to allocate a public IP address ↗.

    fly ips allocate-v6 --app <pg-app-name>

  2. Configure an external service ↗ by modifying the contents of your fly.toml file. Run the following command to download the fly.toml file.

    fly config save --app <pg-app-name>

    Then, replace the services and services.ports section of the file with the following toml snippet:

    [[services]]
      internal_port = 5432 # Postgres instance
      protocol = "tcp"
    

    [[services.ports]]
      handlers = ["pg_tls"]
      port = 5432

  3. Deploy the new configuration ↗.

  4. Obtain the connection string ↗, which is in the form of:

    postgres://{username}:{password}@{public-hostname}:{port}/{database}?options

2. Create a database configuration

To configure Hyperdrive, you will need:

  • The IP address (or hostname) and port of your database.
  • The database username (for example, hyperdrive-demo) you configured in a previous step.
  • The password associated with that username.
  • The name of the database you want Hyperdrive to connect to. For example, postgres.

Hyperdrive accepts the combination of these parameters in the common connection string format used by database drivers:

postgres://USERNAME:PASSWORD@HOSTNAME_OR_IP_ADDRESS:PORT/database_name

Most database providers will provide a connection string you can directly copy-and-paste directly into Hyperdrive.

To create a Hyperdrive configuration with the Wrangler CLI, open your terminal and run the following command. Replace <NAME_OF_HYPERDRIVE_CONFIG> with a name for your Hyperdrive configuration and paste the connection string provided from your database host, or replace user, password, HOSTNAME_OR_IP_ADDRESS, port, and database_name placeholders with those specific to your database:

Terminal window
npx wrangler hyperdrive create <NAME_OF_HYPERDRIVE_CONFIG> --connection-string="postgres://user:password@HOSTNAME_OR_IP_ADDRESS:PORT/database_name"

Hyperdrive will attempt to connect to your database with the provided credentials to verify they are correct before creating a configuration. If you encounter an error when attempting to connect, refer to Hyperdrive's troubleshooting documentation to debug possible causes.

This command outputs a binding for the Wrangler configuration file:

{
  "name": "hyperdrive-example",
  "main": "src/index.ts",
  "compatibility_date": "2024-08-21",
  "compatibility_flags": [
    "nodejs_compat"
  ],
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",
      "id": "<ID OF THE CREATED HYPERDRIVE CONFIGURATION>"
    }
  ]
}

3. Use Hyperdrive from your Worker

Install the node-postgres driver:

Terminal window
npm i pg@>8.16.3

The minimum version of node-postgres required for Hyperdrive is 8.16.3.

If using TypeScript, install the types package:

Terminal window
npm i -D @types/pg

Add the required Node.js compatibility flags and Hyperdrive binding to your wrangler.jsonc file:

{
  "compatibility_flags": [
    "nodejs_compat"
  ],
  "compatibility_date": "2024-09-23",
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",
      "id": "<your-hyperdrive-id-here>"
    }
  ]
}

Create a new Client instance and pass the Hyperdrive connectionString:

// filepath: src/index.ts
import { Client } from "pg";


export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
    // Create a new client instance for each request.
    const client = new Client({
      connectionString: env.HYPERDRIVE.connectionString,
    });


    try {
      // Connect to the database
      await client.connect();
      console.log("Connected to PostgreSQL database");


      // Perform a simple query
      const result = await client.query("SELECT * FROM pg_tables");


      // Clean up the client after the response is returned, before the Worker is killed
      ctx.waitUntil(client.end());


      return Response.json({
        success: true,
        result: result.rows,
      });
    } catch (error: any) {
      console.error("Database error:", error.message);


      new Response('Internal error occurred', { status: 500 });
    }
  },
};

If you expect to be making multiple parallel database queries within a single Worker invocation, consider using a connection pool (pg.Pool) ↗ to allow for parallel queries. If doing so, set the max connections of the connection pool to 5 connections. This ensures that the connection pool fits within Workers' concurrent open connections limit of 6, which affect TCP connections that database drivers use.

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