Docs example for distributed repos

[rklonner]

The FAQs say

Does it work with a distributed Argo CD repository setup?
Short answer: Maybe... It depends on what you are trying to achieve.

Longer answer: The tool is not specifically designed to work with a distributed Argo CD repository setup, where applications and their manifests are spread across multiple repositories.

Do you mean by a "distributed Argo CD repository setup" that ArgoCD application manifests and k8s application manifests are separated in different repositories?

Because that was my initial use case when I tried the tool. In this case I have shared responsibilities, k8s manifests are in developer responsibility, ArgoCD manifests in platform engineer responsibility. Therefore each kind of manifests are in different repos. I wanted to give both parties the opportunity to use ArgoCD Diff Preview in PRs.

It took me some time to realize that for the developer use case I can accomplish that if I clone two times the main branch of the ArgoCD application manifests (constant, no change) and then mention the repo of the k8s manifests and its branch during execution of argocd-diff-preview.

If that kind of workflow was the intention in your FAQ entry I would like to add a general example to showcase this, I tried that here with my example repos:

# checkout 2 times the same state of ArgoCD manifests (leave branch constant at main)
git clone https://github.com/rklonner/argocd-example-guestbook.git base-branch --depth 1 -q
git clone https://github.com/rklonner/argocd-example-guestbook.git target-branch --depth 1 -q

# checkout the k8s manifest to diff on from a different repo -> rklonner/argocd-example-apps
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 TARGET_BRANCH=test-argocd-diff
-e REPO=rklonner/argocd-example-apps
dagandersen/argocd-diff-preview:v0.1.19

Combined with an illustration incl. commands like mentioned here this could make it more clear for others.

[dag-andersen]

Do you mean by a "distributed Argo CD repository setup" that ArgoCD application manifests and k8s application manifests are separated in different repositories?

@rklonner
Yes, basically. Any kind of setup that is not a "mono"-repo for all Kubernetes "files" :)

It took me some time to realize that for the developer use case I can accomplish that if I clone two times the main branch of the ArgoCD application manifests (constant, no change) and then mention the repo of the k8s manifests and its branch during execution of argocd-diff-preview.

Yes, that is also partially how we do it at Egmont :)

I have not added an example for it in the docs, because I think it is hard to describe the setup clearly. People have so many different ways of setting up their Argo CD configuration, so I worry that the docs create more confusion than they help.

Combined with an illustration incl. commands like mentioned https://github.com/dag-andersen/argocd-diff-preview/issues/259this could make it more clear for others.

But as you are saying, if we have a nice illustration of how the tool works, maybe it is easier to understand :)