feat(appset): Advanced templating for ApplicationSet

[speedfl]

Signed-off-by: gmuselli geoffrey.muselli@gmail.com

@crenshaw-dev I think you were interested by this one

Closes #11164
Closes #9177

Main purpose is to have an ApplicationSet Template as map[string]interface{} which can be fully templatable

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: guestbook
spec:
  goTemplate: true
  generators:
  - list:
      elements:
      - cluster: engineering-dev
        url: https://kubernetes.default.svc
        automated: true
        prune: true
      - cluster: engineering-prod
        url: https://kubernetes.default.svc
        automated: true
        prune: false
      - cluster: engineering-debug
        url: https://kubernetes.default.svc
        automated: false
        prune: false
  template:
    metadata:
      name: '{{.cluster}}'
    spec:
      project: default
      source:
        repoURL: https://github.com/argoproj/argo-cd.git
        targetRevision: HEAD
        path: applicationset/examples/list-generator/guestbook/{{.cluster}}
      destination:
        server: '{{.url}}'
        namespace: guestbook
      syncPolicy:
        # If automated == true, it will generate a key 'automated' which is part of the Application Spec model. It will then be retained
        # If automated == false, it will generate a key 'noAuto' which is not part of the Application Spec model. It will then be ignored
        '{{ ternary "automated" "noAuto" .automated }}':
          # If prune == true, it will generate a key 'prune' which is part of the Application Spec model. It will then be retained
          # If prune == false, it will generate a key 'noprune' which is not part of the Application Spec model. It will then be ignored
          '{{ ternary "prune" "noprune" .prune }}': true

Note on DCO:

If the DCO action in the integration test fails, one or more of your commits are not signed off. Please click on the Details link next to the DCO action for instructions on how to resolve this.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• Optional. My organization is added to USERS.md.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).

[codecov]

Codecov Report

Patch coverage: 40.40% and project coverage change: -0.16 ⚠️

Comparison is base (a695aa8) 49.15% compared to head (e94488e) 49.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11567      +/-   ##
==========================================
- Coverage   49.15%   49.00%   -0.16%     
==========================================
  Files         248      248              
  Lines       42891    43002     +111     
==========================================
- Hits        21082    21071      -11     
- Misses      19691    19807     +116     
- Partials     2118     2124       +6     

Impacted Files	Coverage Δ
applicationset/generators/duck_type.go	70.18% <0.00%> (ø)
applicationset/generators/pull_request.go	52.23% <0.00%> (ø)
applicationset/generators/scm_provider.go	34.19% <0.00%> (ø)
.../apis/application/v1alpha1/applicationset_types.go	29.26% <ø> (+0.69%)	⬆️
util/argo/argo.go	64.40% <0.00%> (-2.06%)	⬇️
cmd/argocd/commands/applicationset.go	18.25% <33.66%> (+1.19%)	⬆️
...licationset/generators/generator_spec_processor.go	64.00% <60.00%> (-2.30%)	⬇️
applicationset/utils/utils.go	61.99% <60.60%> (-13.60%)	⬇️
...cationset/controllers/applicationset_controller.go	63.15% <100.00%> (-0.29%)	⬇️
applicationset/generators/cluster.go	80.27% <100.00%> (ø)
... and 4 more

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[crenshaw-dev]

@speedfl you're a force of nature.

I doubt I'll personally have time to review this in time for 2.6. But if the community likes the approach, I'd love to get it into 2.7.

[michalschott]

@crenshaw-dev can you explain how can we as community motivate you more to "merge it asap as this is what we need"? 😄

[boedy]

Interesting approach. I think this is exactly what I need. Would we be to toggle automated by using only a single variable as in the example bellow?

syncPolicy:
  '{{ ternary "automated" "noAuto" .automated }}':
    prune: true
    selfHeal: true

[speedfl]

@boedy yes. You Can take a look to examples and e2e

[mubarak-j]

apologies if this repeating the same question, but can parameter values provided by various generators be used as a condition here, e.g labels provided by cluster generator?

kind: ApplicationSet
spec:
  goTemplate: true
  template:
    spec:
      syncPolicy:
{{- if eq (index .metadata.labels "env") "staging" }}
        automated: {}
{{- end }}

[crenshaw-dev]

@crenshaw-dev can you explain how can we as community motivate you more to "merge it asap as this is what we need"? 😄

@michalschott pay Intuit to clone me. ;-) But seriously, I'll be advocating with my PM to get my time assigned to this before 2.7.

@mubarak-j templates outside of keys or string-type values are not part of this PR. For that, you'll need this: #11183

[crenshaw-dev]

Oh! But @mubarak-j, you could accomplish the same thing by doing this:

kind: ApplicationSet
spec:
  goTemplate: true
  template:
    spec:
      syncPolicy:
        '{{ ternary "automated" "noAuto" (eq (index .metadata.labels "env") "staging")}}': {}

My bad, I was looking at the exact text of your example instead of the intention. :-)

[speedfl]

@crenshaw-dev Hope you are doing well. A little present :), I rebased from master with small improvments compared to previous version.

Initially only the spec in the template was fully templatable. Now the entire template is a raw Json so that we can as well template metadata (ie: conditional finalizers)

Added documentation + e2e

[crenshaw-dev]

@speedfl that's awesome, thanks!

I just got approval to spend time reviewing this for 2.7. It'll be a couple weeks before I can dive in.

A couple notes:

1. it would be nice to still build a "full CRD" for folks to use in their IDEs - but I'd consider that nice-to-have
2. with the whole Application being templateable, I think we'll need to add code to protect the status field (and maybe one or two other top-level fields that might exist - I need to look at the Application CRD).

[speedfl]

@crenshaw-dev

Thanks a lot for the suggestion. I will add the status field protection in applicationset_controller.validateGeneratedApplications + unit tests

Let me know if you have other fields in mind

Concerning the CRD I will try to think about it. If you have suggestion they are welcome.
The main problem is that map[string]interface{} is not working with kubebuilder. That's why I had to use the JSON with Raw String kubernetes-sigs/controller-tools#636. And I don't think it is possible to declare fields inside the Json

[crenshaw-dev]

@speedfl would you mind resolving conflicts?

Makes sense w.r.t. the CRD. I think it's fine to leave it plain-json.

[crenshaw-dev]

Probably a version difference. Try running make install-go-tools-local && make install-codegen-tools-local.

[speedfl]

All done @crenshaw-dev Have a good weekend :)

[vl-kp]

any update?

[speedfl]

@vl-kp I will take it back soon. I think it could be interesting to merge it just after the official release 2.7 so that we have time to test it for 2.8. it is a quite big PR. what do you think @crenshaw-dev

[crenshaw-dev]

Yep, that makes sense. I also wanna make some quick effort to see if we can still use the ApplicationSpec struct for CRD generation but use preserve-fields to make sure the code can access all fields. I just haven't had time to try it.

[FCosta999]

Any idea when this is going to be merged?

[speedfl]

@FCosta999 I am sorry but I am not sure I will be able to work on this one for 2.8 but I can prioritize.
@crenshaw-dev did you have time to check the crd generation ?

[blakepettersson]

This has been superceded by #14893 right?