Access environment variables in custom server

[NewBieBR]

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

[timneutkens]

I'll post the same reply as here, as it applies in the same way: #12254 (comment)

If you want to create API endpoints it's recommended to use API routes: nextjs.org/docs/api-routes/introduction. API routes are automatically compiled through Next.js' compilation pipeline and allow you to use import/export syntax and a bunch of other syntax that hasn't landed in Node.js yet, similar to pages.

If you use a custom server you're basically handing off a request to Next.js and Next.js is unaware of the server existing, it also boots up after the server boots up, meaning we can't compile the server, hence why you can only use Node.js features and Node.js currently does not compile import syntax.

[NewBieBR]

I want to use a custom server.

This scenario is straight from the nextjs offical firebase authentication example. And is deployed on vercel. In server.js we need to use credentials from firebase.

Is there any alternative solution without pushing the private credentials to deploy?

[rachelgould]

I'm dealing with this same issue right now

[timneutkens]

dotenv is already automatically supported when you run next(), closing this as the new environment support sort of covers it: https://nextjs.org/blog/next-9-4#new-environment-variables-support

[kvedantmahajan]

Running custom server on next 10 and using .env or .env.development does not work. it is undefined.

Refer - #20271 for my setup details. @timneutkens

[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')

[endrureza]

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')

this is the only one that works for me

[nikkufans]

.env.local

MY_ENV_VARIABLE=hello

server.js

const app = next({ isDev })

app.prepare().then(() => {
  // To be exactly, you can access environment variables after next().prepare()
  console.log(process.env.MY_ENV_VARIABLE)  // print  hello
})

[arnaugomez]

.env.local

MY_ENV_VARIABLE=hello

server.js

const app = next({ isDev })

app.prepare().then(() => {
  // To be exactly, you can access environment variables after next().prepare()
  console.log(process.env.MY_ENV_VARIABLE)  // print  hello
})

This worked for our project. Looks like environment variables only show up once the next.js app is prepared and the prepare method has been called.

[nemanjam]

Where is the reference docs for import { loadEnvConfig } from '@next/env'? I want to see more information about arguments.

[endrureza]

Where is the reference docs for import { loadEnvConfig } from '@next/env'? I want to see more information about arguments.

its in here Environment Variables

[nemanjam]

Where is the reference docs for import { loadEnvConfig } from '@next/env'? I want to see more information about arguments.

its in here Environment Variables

I know that, I meant more detailed reference about arguments.

[balazsorban44]

This issue has been automatically locked due to no recent activity. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.