Built-in Policy Type

This documentation will walk through the built-in policies.

apply-once

Overview

Allow configuration drift for applied resources.

Parameter

Name	Type	Description
enable	bool	If true, allow configuration drift.

Example

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: apply-once-app
spec:
  components:
    - name: hello-world
      type: webservice
      properties:
        image: oamdev/hello-world
      traits:
        - type: scaler
          properties:
            replicas: 1
  policies:
    - name: apply-once
      type: apply-once
      properties:
        enable: true

garbage-collect

Overview

Configure the garbage collection behavior for the application.

Parameter

Name	Type	Description
keepLegacyResource	bool	If true, outdated versioned resourcetracker will not be recycled automatically. Outdated resources will be kept until resourcetracker be deleted manually.
rules	[]GarbageCollectPolicyRule	A list of rules to control gc strategy at resource level, if one resource is controlled by multiple rules, first rule will be used.

GarbageCollectPolicyRule

Name	Type	Description
selector	GarbageCollectPolicyRuleSelector	Select the target resources of the rule.
strategy	String	The strategy for target resources to recycle. Available values: never, onAppDelete, onAppUpdate.

GarbageCollectPolicyRuleSelector

Name	Type	Description
componentNames	[]String	Select target resources by component names.
componentTypes	[]String	Select target resources by component types.
traitTypes	[]String	Select target resources by trait types.

Example

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: first-vela-app
spec:
  components:
    - name: express-server
      type: webservice
      properties:
        image: oamdev/hello-world
        port: 8000
      traits:
        - type: ingress-1-20
          properties:
            domain: testsvc.example.com
            http:
              "/": 8000
  policies:
    - name: keep-legacy-resource
      type: garbage-collect
      properties:
        keepLegacyResource: true

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: garbage-collect-app
spec:
  components:
    - name: hello-world-new
      type: webservice
      properties:
        image: oamdev/hello-world
      traits:
        - type: expose
          properties:
            port: [8000]
  policies:
    - name: garbage-collect
      type: garbage-collect
      properties:
        rules:
          - selector:
              traitTypes:
                - expose
            strategy: onAppDelete

Override

Overview

Describe the configuration to override when deploying resources.

Parameter

Name	Type	Description
components	[]ComponentPatch	A list of component configurations to override.
selector	[]String	A list of component names to use. If not set, all components will be used.

ComponentPatch

Name	Type	Description
name	string	The name of the component to override. If not set, it will match all components with the specified type. Can be used with wildcard * for fuzzy match.
type	String	The type of the component to override. If not set, all component types will be matched.
properties	Object	The component properties to merge.
traits	[]TraitPatch	A list of trait configurations to override.

TraitPatch

Name	Type	Description
type	String	The type of the trait to override.
properties	Object	The trait properties to merge.
disable	bool	If true, this trait will be removed.

Examples

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: deploy-with-override
  namespace: examples
spec:
  components:
    - name: nginx-with-override
      type: webservice
      properties:
        image: nginx
  policies:
    - name: topology-hangzhou-clusters
      type: topology
      properties:
        clusterLabelSelector:
          region: hangzhou
    - name: topology-local
      type: topology
      properties:
        clusters: ["local"]
        namespace: examples-alternative
    - name: override-nginx-legacy-image
      type: override
      properties:
        components:
          - name: nginx-with-override
            properties:
              image: nginx:1.20
    - name: override-high-availability
      type: override
      properties:
        components:
          - type: webservice
            traits:
              - type: scaler
                properties:
                  replicas: 3
  workflow:
    steps:
      - type: deploy
        name: deploy-local
        properties:
          policies: ["topology-local"]
      - type: deploy
        name: deploy-hangzhou
        properties:
          policies: ["topology-hangzhou-clusters", "override-nginx-legacy-image", "override-high-availability"]

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: advance-override
  namespace: examples
spec:
  components:
    - name: nginx-advance-override-legacy
      type: webservice
      properties:
        image: nginx:1.20
    - name: nginx-advance-override-latest
      type: webservice
      properties:
        image: nginx
  policies:
    - name: topology-hangzhou-clusters
      type: topology
      properties:
        clusterLabelSelector:
          region: hangzhou
    - name: topology-local
      type: topology
      properties:
        clusters: ["local"]
        namespace: examples-alternative
    - name: override-nginx-legacy
      type: override
      properties:
        selector: ["nginx-advance-override-legacy"]
    - name: override-nginx-latest
      type: override
      properties:
        selector: ["nginx-advance-override-latest", "nginx-advance-override-stable"]
        components:
          - name: nginx-advance-override-stable
            type: webservice
            properties:
              image: nginx:stable
  workflow:
    steps:
      - type: deploy
        name: deploy-local
        properties:
          policies: ["topology-local", "override-nginx-legacy"]
      - type: deploy
        name: deploy-hangzhou
        properties:
          policies: ["topology-hangzhou-clusters", "override-nginx-latest"]

topology

Overview

Describe the destination where components should be deployed to.

Parameter

Name	Type	Description
clusters	[]string	The names of the clusters to select.
clusterLabelSelector	mpa[string]string	The label selector for clusters. Exclusive to "clusters"
namespace	string	The target namespace to deploy in the selected clusters. If not set, components will inherit the original namespace.

Example

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: basic-topology
  namespace: examples
spec:
  components:
    - name: nginx-basic
      type: webservice
      properties:
        image: nginx
  policies:
    - name: topology-hangzhou-clusters
      type: topology
      properties:
        clusters: ["hangzhou-1", "hangzhou-2"]

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: label-selector-topology
  namespace: examples
spec:
  components:
    - name: nginx-label-selector
      type: webservice
      properties:
        image: nginx
  policies:
    - name: topology-hangzhou-clusters
      type: topology
      properties:
        clusterLabelSelector:
          region: hangzhou

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: local-ns-topology
  namespace: examples
spec:
  components:
    - name: nginx-local-ns
      type: webservice
      properties:
        image: nginx
  policies:
    - name: topology-local
      type: topology
      properties:
        clusters: ["local"]
        namespace: examples-alternative