litmus/executor

Litmus Chaos Executor

• The executor runs the litmus jobs & monitors them. Typically invoked by the litmuschaos operator to run experiments listed in the chaosengine
• To learn more about the chaosengine & chaosexperiment resources, see chaos operator

How to Override ChaosExperiment defaults

• To override the ENV variables in the chaos experiment CRs, perform one of the below steps before applying the manifest:

  • Make changes in the ChaosExperiment CR manifest,

  apiVersion: litmuschaos.io/v1alpha1
  description:
    message: |
      Deletes a pod belonging to a deployment/statefulset/daemonset
  kind: ChaosExperiment
  metadata:
    name: kubernetes-state-pod-delete-v0.1.0
    version: 0.1.0
  spec:
    definition:
      args:
      - -c
      - ansible-playbook ./experiments/chaos/kubernetes/pod_delete/test.yml -i /etc/ansible/hosts
        -vv; exit 0
      command:
      - /bin/bash
      env:
      - name: ANSIBLE_STDOUT_CALLBACK
        value: default
      - name: TOTAL_CHAOS_DURATION 
        value: 15                        <---- EDIT HERE
      - name: CHAOS_INTERVAL
        value: 5
      - name: LIB
        value: ""
      image: ""
      labels:
        name: pod-delete
      litmusbook: /experiments/chaos/kubernetes/pod_delete/run_litmus_test.yml
  

• Add those variables in the component spec of the respective experiments in the chaosEngine CR manifest

  apiVersion: litmuschaos.io/v1alpha1
  kind: ChaosEngine
  metadata:
    name: engine-nginx
    namespace: default
  spec:
    monitorenable: true 
    appinfo:
      appkind: deployment
      applabel: app=nginx
      appns: default    
    chaosServiceAccount: nginx
    experiments:
    - name: container-kill
      spec:
        components:
        - name: TARGET_CONTAINER   <------ ADD HERE  
          value: jackma
  

How to Delete stale / completed jobs after chaosExperiment Execution

• To ensure the completed experiment jobs are removed, set spec.jobCleanupPolicy to delete

  apiVersion: litmuschaos.io/v1alpha1
  kind: ChaosEngine
  metadata:
    name: engine-nginx
    namespace: litmus 
  spec:
    jobCleanUpPolicy: ""  <-------------- ADD HERE
    appinfo: 
      appns: litmus
      # FYI, To see app label, apply kubectl get pods --show-labels
      applabel: "app=hello-deployment" 
    chaosServiceAccount: litmus 
    experiments:
      - name: pod-delete
        spec:
          components:
          - name: FORCE
            value: "true"
  

How to Override Executor and Exporter image

• To provide a chaos executor (runner) & exporter (monitor) of choice, provide the image names (in the form registry/user/image:tag) in the chaosEngine as shown below. The defaults at this point correspond to the litmuschaos CI images in dockerhub:

  • Executor: litmuschaos/ansible-runner:ci
  • Monitor: litmuschaos/chaos-exporter:ci

• Make changes in the ChaosEngine CR manifest,

  apiVersion: litmuschaos.io/v1alpha1
  kind: ChaosEngine
  metadata:
    name: engine-nginx
    namespace: litmus 
  spec:
    jobCleanUpPolicy: ""  
    appinfo: 
      appns: litmus
      # FYI, To see app label, apply kubectl get pods --show-labels
      applabel: "app=hello-deployment"
    components:
      monitor:
        image: ""     <----------- ADD EXPORTER(MONITOR) IMAGE HERE
      runner:
        image: ""      <----------- ADD EXECUTOR(RUNNER) IMAGE HERE
    chaosServiceAccount: litmus 
    experiments:
      - name: pod-delete
        spec:
          components:
          - name: FORCE
            value: "true"
  

Limitations

• The name of file which contains data for configmap in experimentCR should be parameters.yml

• The configmap is mounted in this default directory: /mnt/

• The secret is mounted in this default directory: /tmp/