# Add your application user to group 1000
RUN usermod -a -G 1000 your-app-user
```

## Environment Variables in Docker Builds

Docker doesn't provide a way to pass in environment variables to a build.
It does, however, provide build args.
Render injects your service's environment variables as build args with the same keys and values.
You can make use of build args in your Dockerfile using the [`ARG` instruction](https://docs.docker.com/engine/reference/builder/#arg).

> We recommend against using <code>ARG</code> instructions for secrets. Consider
>   using <a href="#secret-files-in-docker-builds">secret files</a> instead for
>   build-time secrets.