How to handle the postgres connection when heroku changes the DATABASE_URL

Question

On Heroku Postgres there is written:

The value of your app’s DATABASE_URL config var might change at any time. You should not rely on this value either inside or outside your Heroku app.

I'm developing a Node.js server that uses node-postgres to connect and manage the connection pool with the database.

But what happens when Heroku changes the DATABASE_URL? How should this problem be managed?

Answer 1

You handle this by always connecting to Postgres using whatever value DATABASE_URL has. For example, you can use this value as a connection string when you create your pool:

const connectionString = process.env.DATABASE_URL

const pool = new Pool({
  connectionString: connectionString,
})

Heroku's dynos restart when their environment variables or addons are changed, which should cause your code to pick up the new database connection string when it starts back up.