feat: Implement Server-Side Diff

[leoluz]

Implement Server-Side Diff
fix: #11574

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).
• The title of the PR conforms to the Toolchain Guide
• 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).
• My new feature complies with the feature status guidelines.
• I have added a brief description of why this PR is necessary and/or what this PR solves.

Please see Contribution FAQs if you have questions about your pull-request.

[crenshaw-dev]

First pass 🎉

[crenshaw-dev]

Small thing: when I toggle argocd.argoproj.io/compare-options from ServerSideDiff=false to ServerSideDiff=true, I have to manually refresh to get the new diff.

I don't think that's a big deal. But if it's easy to force a recalculation of the diff, I think that would be ideal.

[crenshaw-dev]

Should add this to the application-controller line in Procfile:

 --server-side-diff-enabled=${ARGOCD_APPLICATION_CONTROLLER_SERVER_SIDE_DIFF:-''}

[leoluz]

Small thing: when I toggle argocd.argoproj.io/compare-options from ServerSideDiff=false to ServerSideDiff=true, I have to manually refresh to get the new diff.

I don't think that's a big deal. But if it's easy to force a recalculation of the diff, I think that would be ideal.

I agree and thought about that during implementation. I didn't find an obvious easy way trigger that. I would have to change the logic to decide if it should use the cache or not a bit and I think that could cause different implications.

[leoluz]

Should add this to the application-controller line in Procfile:

 --server-side-diff-enabled=${ARGOCD_APPLICATION_CONTROLLER_SERVER_SIDE_DIFF:-''}

Added.
Thank you

[codecov]

Codecov Report

Attention: 46 lines in your changes are missing coverage. Please review.

Comparison is base (4875b02) 49.53% compared to head (579b1ed) 49.48%.
Report is 37 commits behind head on master.

Files	Patch %	Lines
util/argo/diff/diff.go	37.50%	19 Missing and 1 partial ⚠️
controller/sync.go	0.00%	14 Missing ⚠️
controller/state.go	71.87%	6 Missing and 3 partials ⚠️
cmd/argocd/commands/admin/app.go	25.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #13663      +/-   ##
==========================================
- Coverage   49.53%   49.48%   -0.05%     
==========================================
  Files         269      271       +2     
  Lines       47321    47726     +405     
==========================================
+ Hits        23441    23619     +178     
- Misses      21576    21772     +196     
- Partials     2304     2335      +31     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[kotyara85]

@leoluz

error when running on 2.11.7

Unable to save changes: application spec for cilium is invalid: InvalidSpecError: Unable to generate manifests in : rpc error: code = Unknown desc = `helm template . --name-template cilium --namespace kube-system --kube-version 1.30 --values /tmp/e1416a6f-b6c5-4a8c-bb6c-dcd4aa41abc2 <api versions removed> --include-crds` failed exit status 1: Error: template: cilium/templates/cilium-operator/deployment.yaml:141:20: executing "cilium/templates/cilium-operator/deployment.yaml" at <include "k8sServiceHost" .>: error calling include: template: cilium/templates/_helpers.tpl:120:37: executing "k8sServiceHost" at <$configmap.data>: wrong type for value; expected map[string]interface {}; got interface {} Use --debug flag to render out invalid YAML

Template example:

{{- $configmapName := "kubeadm-config" }}
{{- $configmapNamespace := "kube-system" }}
{{- $configmap := (lookup "v1" "ConfigMap" $configmapNamespace $configmapName) }}
apiVersion: v1
data:
    clusterName: {{ ($configmap.data.ClusterConfiguration | fromYaml).clusterName }}
kind: ConfigMap
metadata:
  name: cluster-config

This works fine with helm template . --dry-run=server, but not with argocd

Here's how I did discover this cilium/cilium#35094