ArgoCD manifest refactoring as a use case of argocd-diff-preview

[rklonner]

In general, when doing ArgoCD applicationset "development" I have 2 problems:

• during initial development I do not see which applications are created by what I write. Afaik argocd appset create --dryrun is only listing names of the applications, but not the rendered yaml. What I am basically looking for is the argocd cli equivalent of kubectl run nginx --image=nginx --dry-run=client -o yaml
• maintaining an application set is hard, when you modify refactor it to see the affect, e.g. moving from an initial list generator to a git generator

ArgoCD Diff Preview would allow for that when checking out the main and feature branch of the ArgoCD manifest repo and leaving the base and target branch for the k8s manifests "constant" at main (or just leave the default if argo and k8s manifests are in the same repo)

If you also think that makes sense and would be worth mentioning as an ArgoCD Diff Preview Use Case I can create an example.

[dag-andersen]

Hi @rklonner :)
Where would you add this "use-case" section in the docs? Would that be a new menu-item maybe, where we start listen use cases?

Nevermind you answered that in #266

[rklonner]

I will prepare an example here.

I have something in mind like switching over from a list generator to a git generator and ensuring that it works the same way.

[rklonner]

@dag-andersen : I know created an example to verify that a applicationset refactoring (list generator to git generator) is successful by created the exact some applications as before. Therefore I created an applicationset that is deploying your example kustomize application already in the codebase.

You can review the diff here and test it with the two new branches in my repo with the following commands

# this would be the future main branch
git clone https://github.com/rklonner/argocd-diff-preview base-branch --depth 1 -q -b add-example-appset-refactoring

# this would be a future example branch in your repo
git clone https://github.com/rklonner/argocd-diff-preview target-branch --depth 1 -q -b add-example-appset-refactoring-refactor-branch

docker run    --network host    -v /var/run/docker.sock:/var/run/docker.sock    -v $(pwd)/output:/output    -v $(pwd)/base-branch:/base-branch    -v $(pwd)/target-branch:/target-branch  -e BASE_BRANCH=add-example-appset-refactoring   -e TARGET_BRANCH=add-example-appset-refactoring-refactor-branch    -e REPO=rklonner/argocd-diff-preview -e FILE_REGEX="examples/appset-kustomize/.*\.yaml"   dagandersen/argocd-diff-preview:v0.1.20

If you like the example I will create a PR of adding the version with the list generator to main.
Not sure how to add the second branch that holds the actual change as an open branch in your repo named something like "example-applicationset-refactoring". I guess it would be easiest if you create it blank and I create a PR on it as I do not have permissions to create branches in your repo directly.

[dag-andersen]

@rklonner I like the example! 🚀🎆 I have created a branch named example-applicationset-refactoring. Let me know if you need anything else from me :)

[rklonner]

@dag-andersen : as aligned in PR I notify you that the example branch is finished in my repo and you can pull it in: https://github.com/rklonner/argocd-diff-preview/tree/demonstrate-appset-refactoring on your branch example-applicationset-refactoring

[dag-andersen]

@rklonner
Sorry for the slow response on this. I have now created the PR :)
Please let me know if you would like a specific title or content in the description.

#302

[rklonner]

@dag-andersen : looks great, thanks for bringing everything together on this PR! I like it.

Title works for me right now.

This question about the title is related to what I asked in this PR regarding the naming convention of the example branches.

However, this Issue is resolved now and can be closed :)

[rklonner]

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