ApplicationSet template is missing toYaml/fromYaml functions

[alexbde]

We do have an use case which I would have thought is a pretty common one: we have an application Helm chart and multiple locations with application configurations. E.g., a git repository with general/common configurations (valid for all stages) & another git repository with stage-specific configurations.

Today we’re using the app-of-apps pattern with Helm charts to read & merge those configs/values.yaml files. Minimal example:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata: ...
spec:
  source:
    helm:
      values: |
        {{- .Values.stage | merge .Values.general | toYaml | nindent 8 }}
...

We tried to move to ApplicationSet instead of app-of-apps because it looks like the securer and more future-proof concept. We were very happy we can now use Go template with Argo CD >= 2.5 and the merging is working perfectly. Sadly, we noticed there is no toYaml/fromYaml function. We’re super close to the goal with the right result, but couldn’t simply print it.

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata: ...
spec:
  generators:
  - ... // merge or matrix with multiple (git) generators
  goTemplate: true
  template:
    metadata: ...
    spec:
      source:
        helm:
          values: |
            {{ (omit . "path") | toYaml }} // not working, missing function, so close!
...

Would it be possible to add this function to the upcoming 2.6 release? There is already a toJson function, which would at least make it work (because json is a subset of yaml). To make it beautiful and more native it would be great to have a toYaml/fromYaml function.

[crenshaw-dev]

@alexbde I'm also surprised those functions aren't available. I'd welcome a PR to add them. Might event consider cherry-picking back to 2.5 if it's a pretty minimal PR.

[alexbde]

@crenshaw-dev Yeah, so was I, I would have actually expected it in the sprig library. I'm not a go developer at all, but I will try to have a look 👍

To whom it may concern: there are toJson/fromJson methods added with argo-cd 2.6, which are an okay-ish workaround (because JSON < YAML) to make it work at least - it's just not beautiful in the UI, because it's JSON ;)

[blakepettersson]

I saw that @alexbde put in an issue in Masterminds/sprig#358, which would be the ideal place to put it. Maybe as a workaround until then we could add those functions directly in utils.go and once (if) it is upstream we could then use that implementation?

[blakepettersson]

There's now a PR in Masterminds/sprig#360

[alexbde]

Wow! Thank you very much for taking care of that @blakepettersson ❤️ Fingers crossed the sprig maintainers will pick it up soon :)

[crenshaw-dev]

I don't see any movement from sprig. Let's do this in Argo CD now, and we can switch to the sprig implementation later if they add it.

[yebolenko]

any update on this?

[speedfl]

I created the PR. I hope to merge as part of next release (2.9)