Environment variables are not passed when using Dockerfile

[MuhammadM1998]

To Reproduce

• Create a new project with the below Dockerfile and select Dockerfile as Build Type

  FROM node:alpine AS base
  
  # Log all env variables
  RUN env | sort 

• Add any env vars by clicking the "Environment" tab and entering them in "Environment Settings"

  

• Build the project, go to the "Deployments" tab, and click on "View"

  

Current vs. Expected behavior

Expected Results

The entered variables should show up in the logs

Actual Results

They don't. The "TEST_FOO" we added doesn't show up.

Provide environment information

OS: Ubuntu 24.04
Dokploy Version: latest (0.24.3)

Which area(s) are affected? (Select all that apply)

Application

Are you deploying the applications where Dokploy is installed or on a remote server?

Same server where Dokploy is installed

Additional context

No response

Will you send a PR to fix it?

Maybe, need help

[onurguzel]

Hello @MuhammadM1998, in your application you should use Build-time variables under Environment tab. I hope this helps with your problem.

[MuhammadM1998]

@onurguzel But that would require defining each env var using ARG in my Dockerfile, right? That would be impractical and a lot of maintenance.

For some reason (I'm not sure why), I have another Laravel app deployed, also using Docker. The env vars are picked up correctly! I guess that the env vars get populated after the build, not before. That's why it doesn't show up in the debug logs, but as the Laravel app is always running, it loads the injected env vars after the build again

[onurguzel]

But that would require defining each env var using ARG in my Dockerfile, right? That would be impractical and a lot of maintenance.

Not really. Anything you define in built-time variables are also available as environment variables to any program you RUN in your Dockerfile. I have several applications using this technique. The only downside is you need to define the variables twice, "Environment settings" for running containers and "Build-time variables" for deployment.

For some reason (I'm not sure why), I have another Laravel app deployed, also using Docker. The env vars are picked up correctly! I guess that the env vars get populated after the build, not before. That's why it doesn't show up in the debug logs, but as the Laravel app is always running, it loads the injected env vars after the build again

Dokploy didn't always had separate variables for build-time, if I remember correctly this was a feature added in the last 6 months. Previously there was only single environment settings that were used both for the deployment step and the running containers. Could your experience with Laravel application be with an older version of Dokploy? It could also be picking up the values you have in .env file. Maybe you keep some default values in your repository? It's hard to say without more knowledge about your app.

Nevertheless, if I may, I suggest that you could at least try by copy/pasting everything in your environment to build-time variables and starting another deploy to see if it solves the issue.

[MuhammadM1998]

I've added the variable to the build env settings. Unfortunately, it still does not work.

[djsisson]

@MuhammadM1998 can you paste your dockerfile, showing where you typed

ARG NUXT_PUBLIC_API_URL

Args are only scoped to the stage they are in, so they need to be just before your build command

[MuhammadM1998]

@djsisson The dockerfile is in the issue description. It just logs the env vars.

I didn't specify ARG in the dockerfile as instructed by @onurguzel . Explicitely specifying an ARG for each environment variable in my Dockerfile then declaring that env variable in both environment and build env are a lot of maintainance and error prone.

[djsisson]

@onurguzel this is just how docker works, if you need a build arg when you build, you specify it in dokploy then add the ARG line in your dockerfile before the build command. And if it's also required at runtime, then you add the line ENV XXXX after it, so you are only ever listing each env in either build or runtime.

I'm not sure how this can be error prone since you usually only need a couple of build args at most.
You do not have to pass in all your env, only the ones required to build an image.

[MuhammadM1998]

It's an SSG app, so I need all the env vars at build time 😅

It's error-prone because for each env I need in my app, I'd have to declare it in my env.ts (we're using zod to parse env), and in Dockerfile (in addition to .env and .env.example ofc). If I forgot/mis-declared the variable in the Dockerfile, I won't know until after I push the code and it fails during the build.

I think a flag that automatically injects environment variables into process.env would make this a lot better & more intuitive.

[djsisson]

dokploy has no control over what is happening inside your build container.

Managing env and build args is just part of development in docker.

[Siumauricio]

But that would require defining each env var using ARG in my Dockerfile, right? That would be impractical and a lot of maintenance.

Not really. Anything you define in built-time variables are also available as environment variables to any program you RUN in your Dockerfile. I have several applications using this technique. The only downside is you need to define the variables twice, "Environment settings" for running containers and "Build-time variables" for deployment.

For some reason (I'm not sure why), I have another Laravel app deployed, also using Docker. The env vars are picked up correctly! I guess that the env vars get populated after the build, not before. That's why it doesn't show up in the debug logs, but as the Laravel app is always running, it loads the injected env vars after the build again

Dokploy didn't always had separate variables for build-time, if I remember correctly this was a feature added in the last 6 months. Previously there was only single environment settings that were used both for the deployment step and the running containers. Could your experience with Laravel application be with an older version of Dokploy? It could also be picking up the values you have in .env file. Maybe you keep some default values in your repository? It's hard to say without more knowledge about your app.

This was correct, previously we used the same variables for both build and runtime, in the end we decided to separate as you may want to have variables in build but not in runtime.

Nevertheless, if I may, I suggest that you could at least try by copy/pasting everything in your environment to build-time variables and starting another deploy to see if it solves the issue.

What @djsisson mentions is correct, it is necessary to use the ARG name property, to be able to reference the build variables is just as the docker documentation https://docs.docker.com/build/building/variables/ mentions it.

I don't really see any problems here, other than the fact that we separate both environment variables into 2 separate phases 6 months ago or something but is the expected behavior.