Why does node adapter throw errors for env. vars not in predefined list?

[richarddavenport]

I'd really like to remove this error, or at least add a configuration so that it won't throw an error. I couldn't find any past discussion or remarks on why it throws this error or behaves this way.

https://github.com/sveltejs/kit/blob/master/packages/adapter-node/src/env.js#L15-L26

const expected = new Set([
	'SOCKET_PATH',
	'HOST',
	'PORT',
	'ORIGIN',
	'XFF_DEPTH',
	'ADDRESS_HEADER',
	'PROTOCOL_HEADER',
	'HOST_HEADER',
	'BODY_SIZE_LIMIT'
]);

if (ENV_PREFIX) {
	for (const name in process.env) {
		if (name.startsWith(ENV_PREFIX)) {
			const unprefixed = name.slice(ENV_PREFIX.length);
			if (!expected.has(unprefixed)) {
				throw new Error(
					`You should change envPrefix (${ENV_PREFIX}) to avoid conflicts with existing environment variables — unexpectedly saw ${name}`
				);
			}
		}
	}
}

For context, we use a pnpm monorepo and use sveltekit for all of our UIs. We use the node adapter for all of them. We use one .env file and have started to simplify our environment variables. We were just doing a "translation", of sorts, in our docker compose/stack files, mapping the environment variable in the .env to the application environment. Example:

services:
  app1:
    environment:
      PORT: ${APP1_PORT}

We are starting to get away from this "mapping/translation" as it's causing a bit of confusion for the team, and maintaining this is becoming a problem.

I'd like to remove this error being thrown, or configure the node adapter to optionally not throw an error.

[richarddavenport]

Got an answer #10878 (comment)