Access environment variables in custom server

Feature request

Is your feature request related to a problem? Please describe.

Environment variables are undefined in a custom server. For example in server.js

...
const app = next({dev});
console.log(process.env.MY_ENV_VARIABLE);
...

In next.config.js:

module.exports = {
  env: {
     MY_ENV_VARIABLE: 'hello',
  },
};

Output:

undefined

Describe the solution you’d like

I would like to be able to use environment variable in a custom server.

Describe alternatives you’ve considered

No

Additional context

No

[feross]

In case it’s helpful to future Google searchers, you can hook into the existing Next.js .env.local, .env, etc. processing by including the following at the top of your custom server:

// Load environment variables from .env, .env.local, etc. This explicit call
// into `@next/env` allows using environment variables before next() is called.
// More info: https://nextjs.org/docs/basic-features/environment-variables
import { loadEnvConfig } from '@next/env'
loadEnvConfig('./', process.env.NODE_ENV !== 'production')

[rachelgould]

I’m dealing with this same issue right now