cannot use environment variables in helm templates

[jstrachan]

this came up here:
#361 (comment)

I think we need a way to pass in template expressions to helm chart values, like we do for envTemplates so that we can pass in, say, the local docker registry ip/port or private registry via environment variables like we can do for building the docker image name.

[afrittoli]

Yeah, that would be handy.
The same could be used also to pull in secrets from environment variables securely set by the CI engine.

[jstrachan]

here's a little PR that implements this.

e.g. I could use the following skaffold.yaml with the private local docker registry inside a dev pod in Jenkins X:

apiVersion: skaffold/v1alpha2
kind: Config
build:
  tagPolicy:
    envTemplate:
      template: "{{.JENKINS_X_DOCKER_REGISTRY_SERVICE_HOST}}:{{.JENKINS_X_DOCKER_REGISTRY_SERVICE_PORT}}/jenkinsx/demo100:{{.VERSION}}"
  artifacts:
  - workspace: .
    docker: {}
  local: {}
deploy:
  helm:
    releases:
    - name: demo100
      chartPath: charts/demo100
      namespace: jx
      setValueTemplates:
        image.repository: "{{.JENKINS_X_DOCKER_REGISTRY_SERVICE_HOST}}:{{.JENKINS_X_DOCKER_REGISTRY_SERVICE_PORT}}/jenkinsx/demo100"
        image.tag: "{{.VERSION}}"

[jstrachan]

let me know if you're happy with this general approach and if so I can try add a test for it

[afrittoli]

The PR looks good to me - from a functionality pov.

[dlorenc]

Let's track this in #543