Make it easier to ignore/allow specific environment variables

[michaelherold]

As far as I can tell, the only way to ignore an environment variable within dip is to add it to the DIP_EARLY_ENV environment variable. This is a reasonable heuristic for what to ignore, but it means that there is an order-dependence to your shell configuration.

What I found is that since I use chruby, which modifies the GEM_HOME and GEM_PATH environment variables, my dip-run containers were not picking up the bundle in my Docker volume and were thus not working.

The reason for that is that my eval "$(dip console)" was being run prior to chruby initializing.

It would be really nice if dip had the ability to allowlist/denylist environment variables to use within the containers. Something like:

environment:
  allowed:
    - BUNDLE_GITHUB__COM
    - RAILS_MASTER_KEY

or

environment:
  denied:
    - GEM_HOME
    - GEM_PATH

I'd be happy to take a crack at an approach if you want.

---

Aside

I'm not really sure what the current behavior is meant for since docker-compose already handles the environment variables that I need within my project. Why do you pass all environment variables in, instead of relying on docker-compose to manage the environment for you?

[bibendi]

Hi Michael!

Why do you pass all environment variables

The main goal is to do not think about all environment variables that may appear in a project, e.g. VERSION=20200421 rails db:migrate:down and many others.

eval "$(dip console)" was being run prior to chruby initializing

I think the workaround is to move chruby under dip in your bashrc.

It would be really nice if dip had the ability to allowlist/denylist environment variables

I need some time to think about what can I do with that.