Karmadactl Usage Conventions

Recommended usage conventions for karmadactl.

karmadactl interpret

Preparation for YAML file

observed-deploy-nginx.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 3
  paused: true
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      nodeSelector:
        foo: bar
      containers:
      - image: nginx
        name: nginx
        resources:
          limits:
            cpu: 100m
status:
  availableReplicas: 2
  observedGeneration: 1
  readyReplicas: 2
  replicas: 2
  updatedReplicas: 2

desired-deploy-nginx.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 3
  paused: false
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx
      serviceAccountName: test-sa

resourceinterpretercustomization.yaml

apiVersion: config.karmada.io/v1alpha1
kind: ResourceInterpreterCustomization
metadata:
  name: declarative-configuration-example
spec:
  target:
    apiVersion: apps/v1
    kind: Deployment
  customizations:
    replicaResource:
      luaScript: >
        local kube = require("kube")
        function GetReplicas(obj)
          replica = obj.spec.replicas
          requirement = kube.accuratePodRequirements(obj.spec.template)
          return replica, requirement
        end
    replicaRevision:
      luaScript: >
        function ReviseReplica(obj, desiredReplica)
          obj.spec.replicas = desiredReplica
          return obj
        end
    retention:
      luaScript: >
        function Retain(desiredObj, observedObj)
          desiredObj.spec.paused = observedObj.spec.paused
          return desiredObj
        end
    statusAggregation:
      luaScript: >
        function AggregateStatus(desiredObj, statusItems)
          if statusItems == nil then
            return desiredObj
          end
          if desiredObj.status == nil then
            desiredObj.status = {}
          end
          replicas = 0
          for i = 1, #statusItems do
            if statusItems[i].status ~= nil and statusItems[i].status.replicas ~= nil then
              replicas = replicas + statusItems[i].status.replicas
            end
          end
          desiredObj.status.replicas = replicas
          return desiredObj
        end
    statusReflection:
      luaScript: >
        function ReflectStatus (observedObj)
          return observedObj.status
        end
    healthInterpretation:
      luaScript: >
        function InterpretHealth(observedObj)
          return observedObj.status.readyReplicas == observedObj.spec.replicas
        end
    dependencyInterpretation:
      luaScript: >
        local kube = require("kube")
        function GetDependencies(desiredObj)
          refs = kube.getPodDependencies(desiredObj.spec.template, desiredObj.metadata.namespace)
          return refs
        end

status-file.yaml

applied: true
clusterName: member1
health: Healthy
status:
  availableReplicas: 1
  readyReplicas: 1
  replicas: 1
  updatedReplicas: 1
---
applied: true
clusterName: member2
health: Healthy
status:
  availableReplicas: 1
  readyReplicas: 1
  replicas: 1
  updatedReplicas: 1

Validate the ResourceInterpreterCustomization configuration

karmadactl interpret -f resourceinterpretercustomization.yaml --check

Execute the ResourceInterpreterCustomization with operation

Execute the InterpretReplica rule

karmadactl interpret -f resourceinterpretercustomization.yaml --observed-file observed-deploy-nginx.yaml --operation=InterpretReplica

Execute the Retain rule

karmadactl interpret -f resourceinterpretercustomization.yaml --desired-file desired-deploy-nginx.yaml --observed-file observed-deploy-nginx.yaml --operation Retain

Execute the ReviseReplica rule

karmadactl interpret -f resourceinterpretercustomization.yaml --desired-replica 3 --observed-file observed-deploy-nginx.yaml --operation ReviseReplica

Execute the InterpretStatus rule

karmadactl interpret -f resourceinterpretercustomization.yaml --observed-file observed-deploy-nginx.yaml --operation InterpretStatus

Execute the InterpretHealth rule

karmadactl interpret -f resourceinterpretercustomization.yaml --observed-file observed-deploy-nginx.yaml --operation InterpretHealth

Execute the InterpretDependency rule

karmadactl interpret -f resourceinterpretercustomization.yaml --desired-file desired-deploy-nginx.yaml --operation InterpretDependency

Execute the AggregateStatus rule

karmadactl interpret -f resourceinterpretercustomization.yaml --desired-file desired-deploy-nginx.yaml --operation AggregateStatus --status-file status-file.yaml