kustomize is a command-line tool supporting template-free, structured customization of declarative configuration targeted to k8s-style objects.
Targeted to k8s means that kustomize has some understanding of API resources, k8s concepts like names, labels, namespaces, etc., and the semantics of resource patching.
kustomize is an implementation of DAM.
Installation
curl -s "https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/hack/install_kustomize.sh" | bash
Basic Usage
Built Into kubectl
Kustomize is built into kubectl. kubectl apply -k acts the same was as kustomize build path/to/some/app | kubectl apply -f -.
Create Base
From Kubernetes Manifests
Search all Kubernetes resources in the current directory and add them to resources
kustomize create --autodetect
From Kustomization Base
Use path/to/base of another kustomization overlay as base to the new one
kustomize create --resources path/to/base
Search current directory and all sub-directories
kustomize create --resources path/to/base --recursive
Build Resources
URL
kustomize build https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld?ref=v1.0.6
Modifying Base
Labels & Annotations
Create new kustomization.yaml from remote resources, adding to all the resources labels app=hello-world and cloud=gcp
$ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 --labels app:hello-world,cloud:gcp $ kustomize build .
Namespace
Create new kustomization.yaml from remote resources, adding namespace attribute to all its resources
kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 --namespace dev kustomize build .
Resource Names
Update name prefix for all the resources
$ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 $ kustomize edit set nameprefix temp $ kustomize build .
Images
Update the image monopole/hello:1 to monopole/hello:latest
$ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 $ kustomize edit set image monopole/hello:1=monopole/hello:latest $ kustomize build .
ConfigMap & Secret
Generate ConfigMap manifests from variables
$ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 $ kustomize edit add configmap hello-world --behavior create --from-literal=host=google.com $ kustomize build .
JSON Patch
Update the number of the replicas
$ cat <<EOF > patch.yaml - op: replace path: /spec/replicas value: 1 EOF $ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 $ kustomize edit add patch --kind Deployment --path patch.yaml $ kustomize build .
Strategic Merge
Add emptyDir volume
$ cat <<EOF > patch.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: the-deployment
spec:
template:
spec:
containers:
- name: the-container
volumeMounts:
- name: emptyDir
mountPath: /appdata
volumes:
- name: emptyDir
emptyDir: {}
EOF
$ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6
$ kustomize edit add patch --kind Deployment --path patch.yaml
$ kustomize build .Remove Resource
Completly omit resources from the final manifest set
$ cat <<EOF > patch.yaml \$patch: delete apiVersion: v1 kind: ConfigMap metadata: name: the-map EOF $ kustomize create --resources https://github.com/kubernetes-sigs/kustomize.git/examples/helloWorld\?ref\=v1.0.6 $ kustomize edit add patch --kind ConfigMap --path patch.yaml $ kustomize build .