|Type||Description||Tested K8s Platform|
|OpenEBS||Kill the OpenEBS control plane pods and check if they are rescheduled and healthy||GKE, EKS|
Ensure that the Litmus Chaos Operator is running by executing
kubectl get podsin operator namespace (typically,
litmus). If not, install from here
Ensure that the
openebs-control-plane-chaosexperiment resource is available in the cluster by executing
kubectl get chaosexperimentsin the
openebsnamespace. If not, install from here
- OpenEBS control plane pods are healthy before chaos injection
- OpenEBS control plane pods are healthy after chaos injection
- This scenario validates graceful & forced terminations of OpenEBS control plane pods
- List of control plane components killed in this experiment:
- Pod kill is achieved using either the litmus or powerfulseal chaos libraries.
- The desired lib can be configured using the env variable
Steps to Execute the Chaos Experiment
This Chaos Experiment can be triggered by creating a ChaosEngine resource on the cluster. To understand the values to be provided in a ChaosEngine specification, refer Getting Started
Follow the steps in the sections below to create the chaosServiceAccount, prepare the ChaosEngine & execute the experiment.
Use this sample RBAC manifest to create a chaosServiceAccount in the desired (openebs) namespace. This example consists of the minimum necessary role permissions to execute the experiment.
Sample Rbac Manifest
apiVersion: v1 kind: ServiceAccount metadata: name: control-plane-sa namespace: openebs labels: name: control-plane-sa apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: control-plane-sa namespace: openebs labels: name: control-plane-sa rules: - apiGroups: ["","litmuschaos.io","batch","apps"] resources: ["pods","deployments","pods/log","events","jobs","configmaps","chaosengines","chaosexperiments","chaosresults"] verbs: ["create","list","get","patch","update","delete"] - apiGroups: [""] resources: ["nodes"] verbs: ["get","list"] apiVersion: rbac.authorization.k8s.io/v1beta1 kind: RoleBinding metadata: name: control-plane-sa namespace: openebs labels: name: control-plane-sa roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: control-plane-sa subjects: - kind: ServiceAccount name: control-plane-sa namespace: openebs
- Provide the application info in
- Override the experiment tunables if desired in
- To understand the values to provided in a ChaosEngine specification, refer ChaosEngine Concepts
Supported Experiment Tunables
|Variables||Description||Specify In ChaosEngine||Notes|
|LIB||The chaos library used to inject the chaos||Optional||Defaults to `litmus`. Supported: `litmus, powerfulseal`|
|INSTANCE_ID||A user-defined string that holds metadata/info about current run/instance of chaos. Ex: 04-05-2020-9-00. This string is appended as suffix in the chaosresult CR name.||Optional||Ensure that the overall length of the chaosresult CR is still < 64 characters|
Sample ChaosEngine Manifest
apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: control-plane-chaos namespace: openebs spec: # It can be true/false annotationCheck: 'false' # It can be active/stop engineState: 'active' appinfo: appns: 'openebs' applabel: 'name=maya-apiserver' appkind: 'deployment' chaosServiceAccount: control-plane-sa monitoring: false # It can be delete/retain jobCleanUpPolicy: 'delete' experiments: - name: openebs-control-plane-chaos spec: components: env: - name: OPENEBS_NAMESPACE value: 'openebs' ## Period to wait before injection of chaos - name: RAMP_TIME value: '10' - name: FORCE value: '' - name: LIB value: ''
Create the ChaosEngine Resource
Create the ChaosEngine manifest prepared in the previous step to trigger the Chaos.
kubectl apply -f chaosengine.yml -n openebs
If the chaos experiment is not executed, refer to the troubleshooting section to identify the root cause and fix the issues.
Watch Chaos progress
View pod terminations by setting up a watch on the pods in the OpenEBS namespace
watch -n 1 kubectl get pods -n openebs
Check Chaos Experiment Result
Check whether the OpenEBS control plane is resilient to the pod failure, once the experiment (job) is completed. The ChaosResult resource naming convention is:
kubectl describe chaosresult control-plane-chaos-openebs-control-plane-chaos -n openebs
- If the verdict of the ChaosResult is
Fail, and/or the OpenEBS components do not return to healthy state post the chaos experiment, then please refer the OpenEBS troubleshooting guide for more info on how to recover the same.
OpenEBS Control Plane Chaos Demo [TODO]
- A sample recording of this experiment execution is provided here.