Leveraging Kustomize for Kubernetes Manifests

Appendix A. Kustomize Default Transformers

Kustomize’s transformers are responsible for modifying and collecting information about resources during the kustomize build or kubectl apply -k processes.

Kustomize provides the transformers shown in Table A-1 as defaults.

Table A-1. Default transformers available in Kustomize

Transformer	Purpose	Example
annotations	Adds annotations to the metadata/annotations field for all resources. Annotations are also added to spec/template/metadata/annotations for Deployment, ReplicaSet, DaemonSet, StatefulSet, Job, and CronJob resources, and spec/jobTemplate/spec/template/metadata/annotations for CronJob resources.	See Figure 2-1
images	Updates the image key value in paths that include con⁠tainers and init​containers subpaths. Constructs a new image entry via the newName, newTag, and digest fields. The name field should match the image key value in a resource.	See Figure 2-2
labels	Adds labels to the metadata/labels field for all resources. Per the API requirements, also adds labels to the spec/selector field in all Service resources and to the spec/selector/matchLabels field in all Deployment resources.	commonLabels: environment: staging
name​Ref⁠eren⁠ces	Contains a list of name references, which represent all of the possible fields where a type could be used as a reference in other types of resources. Used to note the other places that a particular type of object might be used in a manifest. Needed so that when the name of an ...