How do you use the env variable in the client?

You should prefix it on the use also

Yes, it works when I build normally and start, but the ones on the client side do not work in the Docker environment. @Chartreux

Maybe you forgot setting up the env variables for Docker environment?

No, I'm sure I set it up properly, I can see it on the server, but I can't see it on the client side.

Have you tried this way? Or debugging the process in the client?

i'm getting the same issue @Patagonian Sheepdog did you solve it?

yes https://www.npmjs.com/package/next-runtime-dotenv

I am having the same problem here. If I read it correctly we can only access NEXT_PUBLIC_SOMETHING on client side only if that env is exposed on build?
(https://nextjs.org/docs/app/building-your-application/configuring/environment-variables#loading-environment-variables)

I bundle my docker image before pushing it, I guess I need to do it on the build phase?

following this discussion here: https://github.com/vercel/next.js/discussions/44628, I figured out it's better to either put the env var in the docker build step or use this package: https://github.com/expatfile/next-runtime-env (more updated than the other one)

shameless ping to @Patagonian Sheepdog