fix: allow recursive dry-run over local sources

[niveau0]

This PR tries to fix the issue using flux build with dry-run and recursion.

We have a setup with nested kustomizations and want to render the whole tree
as yaml files, including postBuild substitutions. Afterwards, this should be
checked via kube-linter.

Currently this seems not possible(?) with the flux-cli together with dry-run,
therefore I made some changes.
Since I don't know all the use cases for flux build, it is hard to tell if this
breaks anything.

Maybe someone with deeper knowledge can review the changes.

The command I use is similar to this:

flux build kustomization flux-system \
--recursive \
--path ./clusters/dev/mykustomizations \
-n flux-system \
--local-sources GitRepository/flux-system/flux-system=./ \
--dry-run \
--kustomization-file ./clusters/dev/flux-system/gotk-sync.yaml

[bkreitch]

Seems reasonable to me. I would just switch branches of if b.dryRun and else in build() and revert blank lines except at line 370. And add following test to cmd/flux/build_kustomization_test.go in TestBuildLocalKustomization:

{
	name:       "build with recursive in dry-run mode",
	args:       "build kustomization podinfo --kustomization-file " + tmpFile + " --path ./testdata/build-kustomization/podinfo-with-my-app --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization --dry-run",
	resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
	assertFunc: "assertGoldenTemplateFile",
},

[niveau0]

@bkreitch , thanks for the advice, I will add a test. But I'm not sure what you mean with the if and else branches, since the if and else in the PR are not related?

[bkreitch]

But I'm not sure what you mean with the if and else branches, since the if and else in the PR are not related?

@niveau0 I mean to reverse if condition so it will be like:

if b.dryRun {
	liveKus = b.kustomization
} else {
	liveKus, err = b.getKustomization(ctx)
	if err != nil {
...

[bkreitch]

@niveau0 and for the test - I think that if you'll put my snippet from above into TestBuildLocalKustomization() instead of TestBuildKustomization() it should be enough and additional files are not needed.

[niveau0]

@niveau0 and for the test - I think that if you'll put my snippet from above into TestBuildLocalKustomization() instead of TestBuildKustomization() it should be enough and additional files are not needed.

@bkreitch ah ok got it now, I think I failed to see the 'Local' part in TestBuildLocalKustomization and got confused.

[stefanprodan]

@niveau0 can you please rebase with upstream main and force push, this PR should have a single commit. Thanks

[niveau0]

@niveau0 can you please rebase with upstream main and force push, this PR should have a single commit. Thanks

@stefanprodan sure, I think I did now :)

[matheuscscp]

I'll review this today

[matheuscscp]

I tested this fix and it correctly rendered all the YAMLS in my Kustomization tree, except for the resources deployed by HelmReleases (as expected)!

This was the command I used:

./flux build kustomization matheus-test-repo \
    --recursive \
    --path ./flux-system \
    -n flux-system \
    --local-sources GitRepository/flux-system/matheus-test-repo=./ \
    --dry-run \
    --kustomization-file ./flux-system/root-kustomization.yaml

This was my Kustomization tree (objects deployed by HelmReleases omitted):

Kustomization/flux-system/matheus-test-repo
├── Kustomization/flux-system/matheus-test-repo-configs
│   ├── ConfigMap/monitoring/flux-grafana-dashboards-dfh45k26mg
│   ├── PodMonitor/monitoring/flux-system
│   └── ServiceMonitor/monitoring/flux-operator
├── Kustomization/flux-system/matheus-test-repo-controllers
│   ├── Namespace/monitoring
│   ├── ServiceAccount/monitoring/flux
│   ├── ClusterRoleBinding/flux-monitoring
│   ├── HelmRelease/flux-system/flux-operator
│   │   └── ...
│   ├── HelmRelease/monitoring/kube-prometheus-stack
│   │   └── ...
│   ├── HelmRelease/monitoring/metrics-server
│   │   └── ...
│   ├── Alert/flux-system/dispatch
│   ├── Provider/flux-system/github-dispatch
│   ├── HelmRepository/monitoring/metrics-server
│   ├── HelmRepository/monitoring/prometheus-community
│   └── OCIRepository/flux-system/flux-operator
├── Kustomization/flux-system/matheus-test-repo-workloads
│   └── ResourceSetInputProvider/flux-system/rsip-gh-app-token-cache-test
└── GitRepository/flux-system/matheus-test-repo

[stefanprodan]

@niveau0 can you please rebase and force push

[niveau0]

@stefanprodan done

[stefanprodan]

LGTM

Thanks @niveau0 🎖️