Option to skip inlining or reading any env vars at build time

[codan84]

Goals

1. In proper CI/CD world I should be able to build a Docker image once and promote it through environments
2. This can't be done right now as next build tries to read bunch of environment variables (yes I read posts and I don't care about dynamic routes, SSR etc, this should not be my concern) - bottom line is: 1 next build, 1 docker image, ALL env vars loaded via .env at runtime!
3. There is no excuse to not have that option.

Non-Goals

1. Removing any kind of optimisations

Background

Right now because I need a bunch of env vars when running next build, some of which get inlined in generated code, I am forced to do either one of these:

1. Build per environment (WRONG approach - one should build once and promote given build through environments)
2. Do any of numerous workarounds to avoid env vars being inlined etc (again, WRONG, I should not have to have a cognitive overload of solving this, I should be focusing on resolving business problem)

Proposal

Give me an option to run build that does not require ANY env vars to be set, no matter how I implement my page.

[m-sanders]

This is possible!

You can split the build into two steps by using the next build experimental option documented here:

#46544

The app will still compile build time env var into source so don’t use them and instead use a runtime env option. For App Router you can use the next-runtime-env npm package. Page Router has first party support for runtime env by using the runtimeConfig next.config option.