Environment variables?

[ajoslin]

It would be awesome if Helmfile could cause Charts.yml to interpolate environment variables.

I currently have my project's deployment in a chart directory in my repo. I pass environment variables in via set:

helm upgrade my-project-$NODE_ENV ./kubernetes/my-project/ \
     --set namespace=$NODE_ENV \
     --set web.imageName=$WEB_NAME \
     --set api.imageName=$API_NAME \
     --set env.dockerRepoUrl=$DOCKER_REPO_PREFIX \
     --set env.dockerImageTag=$DOCKER_REPO_TAG \
     --set env.hostname=$NODE_ENV.$KUBERNETES_HOST \
     --install --debug

This is just about the only imperative part of my build step. I'd love to move it into the Helmfile format, but it'd be nice not to have to add a step to run my Helmfile through envsubst.

What do you think of the idea of Helmfile doing environment variable substitution on its own?

[roboll]

I'm not quite convinced this is a good idea, but it would be relatively simple to template the file. One of the things I like most about the current approach is having everything encoded in the helmfile.

I'm not using kubernetes much right now though, so if you think this is a worthy change and can't think of a way to do it without env vars in the file, feel free to submit a pr and I'll accept.

Running it through text/template with a env function would let you have something like {{ env "KEY" "fallback-value" }} maybe.

[natevecc]

I created #2 to address my need for environment variable support. It doesn't do anything fancy with text/template but instead exposes a way for the Chart.yaml file to grab them from the current execution context. Interested in your feedback.

[roboll]

This is available in v0.4.