Kustomization allowed filename patterns documentation

[v1nsai]

I spent several hours yesterday troubleshooting an issue with what felt like an "invisible" file in my cloudflare deployment located here.

When the file was namedcloudflare/app/sealed-secret-values.yaml, I got an error about the file not being found. Full error here for reference:
kustomize build failed: accumulating resources: accumulation err='accumulating resources from './cloudflare/app': read /tmp/kustomization-3853049343/projects/cloudflare/app: is a directory': recursed accumulation of path '/tmp/kustomization-3853049343/projects/cloudflare/app': accumulating resources: accumulation err='accumulating resources from 'sealed-secrets.yaml': open /tmp/kustomization-3853049343/projects/cloudflare/app/sealed-secrets.yaml: no such file or directory': must build at directory: not a valid directory: evalsymlink failure on '/tmp/kustomization-3853049343/projects/cloudflare/app/sealed-secrets.yaml' : lstat /tmp/kustomization-3853049343/projects/cloudflare/app/sealed-secrets.yaml: no such file or directory

After hours of struggling with it, I renamed the file to sealed-secrets.yaml and updated the kustomization.yaml and suddenly the file was visible and everything worked as expected. I fiddled with it a bit more and discovered that the filename sealedsecret-values.yaml was also invalid and made the file "invisible".

Is there documentation on allowed filenames somewhere that I've missed? It might be a good idea to document these filename requirements in the official docs and/or in the error message.

I'm looking through the source code for kustomize.config.k8s.io/v1beta1.kustomization and kustomize.toolkit.fluxcd.io/v1.kustomization but I don't speak golang very well so it might take me a while to drill down to these filename restrictions.

[stefanprodan]

Here is the documentation for the default ignore patterns: https://fluxcd.io/flux/components/source/gitrepositories/#default-exclusions