VM Poweroff

Introduction¶

It causes VMWare VMs to Stop/Power-off before bringing them back to Powered-on state after a specified chaos duration using the VMWare APIs to start/stop the target VM.
It helps to check the performance of the application/process running on the VMWare VMs.

Scenario: poweroff the vm

VM Poweroff

Uses¶

View the uses of the experiment

coming soon

Prerequisites¶

Verify the prerequisites

Ensure that Kubernetes Version > 1.16
Ensure that the Litmus Chaos Operator is running by executing kubectl get pods in operator namespace (typically, litmus).If not, install from here
Ensure that the vm-poweroff experiment resource is available in the cluster by executing kubectl get chaosexperiments in the desired namespace. If not, install from here
Ensure that you have sufficient Vcenter access to stop and start the VM.

(Optional) Ensure to create a Kubernetes secret having the Vcenter credentials in the CHAOS_NAMESPACE. A sample secret file looks like:

apiVersion: v1
kind: Secret
metadata:
  name: vcenter-secret
  namespace: litmus
type: Opaque
stringData:
    VCENTERSERVER: XXXXXXXXXXX
    VCENTERUSER: XXXXXXXXXXXXX
    VCENTERPASS: XXXXXXXXXXXXX

Note: You can pass the VM credentials as secrets or as an chaosengine ENV variable.

Default Validations¶

View the default validations

VM should be in healthy state.

Minimal RBAC configuration example (optional)¶

NOTE

If you are using this experiment as part of a litmus workflow scheduled constructed & executed from chaos-center, then you may be making use of the litmus-admin RBAC, which is pre installed in the cluster as part of the agent setup.

View the Minimal RBAC permissions

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: vm-poweroff-sa
  namespace: default
  labels:
    name: vm-poweroff-sa
    app.kubernetes.io/part-of: litmus
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: vm-poweroff-sa
  labels:
    name: vm-poweroff-sa
    app.kubernetes.io/part-of: litmus
rules:
  # Create and monitor the experiment & helper pods
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["create","delete","get","list","patch","update", "deletecollection"]
  # Performs CRUD operations on the events inside chaosengine and chaosresult
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create","get","list","patch","update"]
  # Fetch configmaps & secrets details and mount it to the experiment pod (if specified)
  - apiGroups: [""]
    resources: ["secrets","configmaps"]
    verbs: ["get","list",]
  # Track and get the runner, experiment, and helper pods log 
  - apiGroups: [""]
    resources: ["pods/log"]
    verbs: ["get","list","watch"]  
  # for creating and managing to execute comands inside target container
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["get","list","create"]
  # for configuring and monitor the experiment job by the chaos-runner pod
  - apiGroups: ["batch"]
    resources: ["jobs"]
    verbs: ["create","list","get","delete","deletecollection"]
  # for creation, status polling and deletion of litmus chaos resources used within a chaos workflow
  - apiGroups: ["litmuschaos.io"]
    resources: ["chaosengines","chaosexperiments","chaosresults"]
    verbs: ["create","list","get","patch","update","delete"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: vm-poweroff-sa
  labels:
    name: vm-poweroff-sa
    app.kubernetes.io/part-of: litmus
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: vm-poweroff-sa
subjects:
- kind: ServiceAccount
  name: vm-poweroff-sa
  namespace: default

Use this sample RBAC manifest to create a chaosServiceAccount in the desired (app) namespace. This example consists of the minimum necessary role permissions to execute the experiment.

Experiment tunables¶

check the experiment tunables

Mandatory Fields

Variables	Description	Notes
APP_VM_MOIDS	MOIDs of the vmware instance	Once you open VM in vCenter WebClient, you can find MOID in address field (VirtualMachine:vm-5365). Alternatively you can use the CLI to fetch the MOID. Eg: vm-5365

Optional Fields

Variables	Description	Notes
TOTAL_CHAOS_DURATION	The total time duration for chaos insertion (sec)	Defaults to 30s
CHAOS_INTERVAL	The interval (in sec) between successive instance termination	Defaults to 30s
SEQUENCE	It defines sequence of chaos execution for multiple instance	Default value: parallel. Supported: serial, parallel
RAMP_TIME	Period to wait before and after injection of chaos in sec

Experiment Examples¶

Common Experiment Tunables¶

Refer the common attributes to tune the common tunables for all the experiments.

Stop/Poweroff VM By MOID¶

It contains MOID of the vm instance. It can be tuned via APP_VM_MOIDS ENV.

Use the following example to tune this:

# power-off the VMWare VM
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: vm-poweroff-sa
  experiments:
  - name: vm-poweroff
    spec:
      components:
        env:
        # MOID of the VM
        - name: APP_VM_MOIDS
          value: 'vm-53,vm-65'

        - name: TOTAL_CHAOS_DURATION
          value: '60'