litmus/mkdocs/docs/experiments/categories/vmware/vm-poweroff.md

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.

!!! tip "Scenario: poweroff the vm"

Uses

??? info "View the uses of the experiment" coming soon

Prerequisites

??? info "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:

    ```yaml
    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

??? info "View the default validations" - VM should be in healthy state.

Minimal RBAC configuration example (optional)

!!! tip "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.

??? note "View the Minimal RBAC permissions"

    [embedmd]:# (https://raw.githubusercontent.com/litmuschaos/chaos-charts/master/charts/vmware/vm-poweroff/rbac.yaml yaml)
    ```yaml
    ---
    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

??? info "check the experiment tunables"

Mandatory Fields

<table>
  <tr>
    <th> Variables </th>
    <th> Description </th>
    <th> Notes </th>
  </tr>
  <tr>
    <td> APP_VM_MOIDS </td>
    <td> MOIDs of the vmware instance</td>
    <td> 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 </td>
  </tr>
</table>

<h2>Optional Fields</h2>

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

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'