kyverno/documentation/writing-policies-generate.md

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Generate Configurations

generate is used to create additional resources when a resource is created. This is useful to create supporting resources, such as role bindings for a new namespace.

Example 1

• rule Creates a ConfigMap with name default-config for all

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: basic-policy
spec:
  rules:
    - name: "Generate ConfigMap"
      match:
        resources:
          kinds: 
          - Namespace
        selector:
          matchLabels:
            LabelForSelector : "namespace2"
      generate:
        kind: ConfigMap # Kind of resource 
        name: default-config # Name of the new Resource
        namespace: "{{request.object.metadata.name}}" # Create in the namespace that triggers this rule
        clone:
          namespace: default
          name: config-template
    - name: "Generate Secret"
      match:
        resources:
          kinds: 
          - Namespace
        selector:
          matchLabels:
            LabelForSelector : "namespace2"
      generate:
        kind: Secret
        name: mongo-creds
        namespace: "{{request.object.metadata.name}}" # Create in the namespace that triggers this rule
        data:
          data:
            DB_USER: YWJyYWthZGFicmE=
            DB_PASSWORD: YXBwc3dvcmQ=
        metadata:
          labels:
            purpose: mongo

In this example, when this policy is applied, any new namespace that satisfies the label selector will receive 2 new resources after its creation:

• ConfigMap copied from default/config-template.
• Secret with values DB_USER and DB_PASSWORD, and label purpose: mongo.

Example 2

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: "default"
spec:
  rules:
  - name: "deny-all-traffic"
    match:
      resources: 
        kinds:
        - Namespace
        name: "*"
    generate: 
      kind: NetworkPolicy
      name: deny-all-traffic
      namespace: "{{request.object.metadata.name}}" # Create in the namespace that triggers this rule
      data:
        spec:
        podSelector:
          matchLabels: {}
          matchExpressions: []
        policyTypes: []
        metadata:
          labels:
            policyname: "default"

In this example, when the policy is applied, any new namespace will receive a NetworkPolicy based on the specified template that by default denies all inbound and outbound traffic.

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