Connect to CockroachDB

This example shows you how to connect Hyperdrive to a CockroachDB Open external link database cluster. CockroachDB is a PostgreSQL-compatible distributed SQL database with strong consistency guarantees.

​​ 1. Allow Hyperdrive access

To allow Hyperdrive to connect to your database, you will need to ensure that Hyperdrive has valid user credentials and network access.

​​ CockroachDB Console

The steps below assume you have an existing CockroachDB Cloud account Open external link and database cluster created.

To create and/or fetch your database credentials:

1. Go to the CockroachDB Cloud console Open external link and select the cluster you want Hyperdrive to connect to.
2. Select SQL Users from the sidebar on the left, and select Add User.
3. Enter a username (for example, `hyperdrive-user), and select Generate & Save Password.
4. Note down the username and copy the password to a temporary location.

To retrieve your database connection details:

1. Go to the CockroachDB Cloud console Open external link and select the cluster you want Hyperdrive to connect to.
2. Select Connect in the top right.
3. Choose the user you created, for example,hyperdrive-user.
4. Select the database, for example defaultdb.
5. Select General connection string as the option.
6. In the text box below, select Copy to copy the connection string.

By default, the CockroachDB cloud enables connections from the public Internet (0.0.0.0/0). If you have changed these settings on an existing cluster, you will need to allow connections from the public Internet for Hyperdrive to connect.

​​ 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:

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

This command outputs a binding for wrangler.toml:

wrangler.toml
name = "hyperdrive-example"
main = "src/index.ts"
compatibility_date = "2023-09-11"

node_compat = true # required for database drivers to function

# Pasted from the output of `wrangler hyperdrive create <NAME_OF_HYPERDRIVE_CONFIG> --connection-string=[...]` above.
[[hyperdrive]]
binding = "HYPERDRIVE"
id = ""

Install the driver:

$ npm install pg

Copy the below Worker code, which passes the connection string generated from env.HYPERDRIVE.connectionString directly to the driver.

src/index.ts
import { Client } from 'pg';

export interface Env {
	// If you set another name in wrangler.toml as the value for 'binding',
	// replace "HYPERDRIVE" with the variable name you defined.
	HYPERDRIVE: Hyperdrive;
}

export default {
	async fetch(request, env, ctx): Promise<Response> {
		console.log(JSON.stringify(env))
		// Create a database client that connects to our database via Hyperdrive
		// Hyperdrive generates a unique connection string you can pass to
		// supported drivers, including node-postgres, Postgres.js, and the many
		// ORMs and query builders that use these drivers.
		const client = new Client({ connectionString: env.HYPERDRIVE.connectionString });

		try {
			// Connect to our database
			await client.connect();

			// Test query
			const result = await client.query({ text: 'SELECT * FROM pg_tables' });

			// Returns result rows as JSON
			return Response.json({ result: result });
		} catch (e) {
			console.log(e);
			return Response.json({ error: e.message }, { status: 500 });
		}
	},
} satisfies ExportedHandler<Env>;

​​ Next steps

• Learn more about How Hyperdrive Works.
• Refer to the troubleshooting guide to debug common issues.
• Understand more about other storage options available to Cloudflare Workers.