kustomize/examples/transformerconfigs/crd/README.md

Transformer Configurations - CRD

This tutorial shows how to add transformer configurations to support a CRD type.

Create a workspace by

DEMO_HOME=$(mktemp -d)

Get Default Config

Get the default transformer configurations by

kustomize config save -d $DEMO_HOME/kustomizeconfig

The default configurations are save in directory $DEMO_HOME/kusotmizeconfig as several files

 commonannotations.yaml  commonlabels.yaml  nameprefix.yaml  namereference.yaml  namespace.yaml  varreference.yaml

Add Config for a CRD

All transformers will be involved for a CRD type. The default configurations already include some common fieldSpec for all types:

• nameprefix is added to .metadata.name
• namespace is added to .metadata.namespace
• labels is added to .metadata.labels
• annotations is added to .metadata.annotations

Thus those fieldSpec don't need to be added to support a CRD type. Consider a CRD type MyKind with fields

• .spec.secretRef.name reference a Secret
• .spec.beeRef.name reference an instance of CRD Bee
• .spec.containers.command as the list of container commands
• .spec.selectors as the label selectors

Add following file to configure the transformers for the above fields

cat > $DEMO_HOME/kustomizeconfig/mykind.yaml << EOF

commonLabels:
- path: spec/selectors
  create: true
  kind: MyKind

nameReference:
- kind: Bee
  fieldSpecs:
  - path: spec/beeRef/name
    kind: MyKind
- kind: Secret
  fieldSpecs:
  - path: spec/secretRef/name
    kind: MyKind

varReference:
- path: spec/containers/command
  kind: MyKind
- path: spec/beeRef/action
  kind: MyKind

EOF

Apply config

Create a kustomization with a MyKind instance.

cat > $DEMO_HOME/kustomization.yaml << EOF
resources:
- resources.yaml

namePrefix: test-

commonLabels:
  foo: bar

vars:
- name: BEE_ACTION
  objref:
    kind: Bee
    name: bee
    apiVersion: v1beta1
  fieldref:
    fieldpath: spec.action
EOF

cat > $DEMO_HOME/resources.yaml << EOF
apiVersion: v1
kind: Secret
metadata:
  name: crdsecret
data:
  PATH: YmJiYmJiYmIK
---
apiVersion: v1beta1
kind: Bee
metadata:
  name: bee
spec:
  action: fly
---
apiVersion: jingfang.example.com/v1beta1
kind: MyKind
metadata:
  name: mykind
spec:
  secretRef:
    name: crdsecret
  beeRef:
    name: bee
    action: \$(BEE_ACTION)
  containers:
  - command:
    - "echo"
    - "\$(BEE_ACTION)"
    image: myapp
EOF

Use the cusotmized transformer configurations by adding those files in kustomization.yaml

cat >> $DEMO_HOME/kustomization.yaml << EOF
configurations:
- kustomizeconfig/mykind.yaml
- kustomizeconfig/commonannotations.yaml
- kustomizeconfig/commonlabels.yaml
- kustomizeconfig/nameprefix.yaml
- kustomizeconfig/namereference.yaml
- kustomizeconfig/namespace.yaml
- kustomizeconfig/varreference.yaml
EOF

Run kustomize build and verify that the namereference is correctly resolved.

test 2 == \
$(kustomize build $DEMO_HOME | grep -A 2 ".*Ref" | grep "test-" | wc -l); \
echo $?    

Run kustomize build and verify that the vars correctly resolved.

test 0 == \
$(kustomize build $DEMO_HOME | grep "BEE_ACTION" | wc -l); \
echo $?