Use different name of the kustomization.yaml

Question

For CI/CD purposes, the project is maintaining 2 kustomization.yaml files

1. Regular deployments - kustomization_deploy.yaml
2. Rollback deployment - kustomization_rollback.yaml

To run kustomize build, a file with the name "kustomization.yaml" is required in the current directory. If the project wants to use kustomization_rollback.yaml and NOT kustomization.yaml, how is this possible? Does kustomize accept file name as an argument? Docs do not specify anything on this.

Answer 1

Currently there is no possibility to change the behavior of kustomize to support other file names (by using precompiled binaries) than:

• kustomization.yaml
• kustomization.yml
• Kustomization

All of the below cases will produce the same error output:

• kubectl kustomize dir/
• kubectl apply -k dir/
• kustomize build dir/

Error: unable to find one of 'kustomization.yaml', 'kustomization.yml' or 'Kustomization' in directory 'FULL_PATH/dir'

Depending on the CI/CD platform/solution/tool you should try other way around like for example:

• split the Deployment into 2 directories kustomization_deploy/kustomization_rollback with kustomization.yaml

---

As a side note!

File names that kustomize uses are placed in the:

• /kubernetes/vendor/sigs.k8s.io/kustomize/pkg/constants/constants.go

// Package constants holds global constants for the kustomize tool.
package constants

// KustomizationFileNames is a list of filenames that can be recognized and consumbed
// by Kustomize.
// In each directory, Kustomize searches for file with the name in this list.
// Only one match is allowed.
var KustomizationFileNames = []string{
  "kustomization.yaml",
  "kustomization.yml",
  "Kustomization",
}

The logic behind choosing the Kustomization file is placed in:

• /kubernetes/vendor/sigs.k8s.io/kustomize/pkg/target/kusttarget.go

---

Additional reference:

• Github.com: Kubernetes-sigs: Kustomize
• Kubernetes.io: Docs: Tasks: Manage kubernetes objects: Kustomization