Skip to main content

Azure Instance Stop

Introduction​

  • It results in PowerOff of an Azure instance before bringing it back to running state after the specified chaos duration.
  • It checks the performance of the application/process running on the instance.
Fault execution flow chart

Azure Instance Stop

Uses​

View the uses of the fault
Coming soon.

Prerequisites​

info
  • Kubernetes > 1.16.
  • Azure access to stop and start the an instance.
  • Use Azure file-based authentication to connect to the instance using Azure GO SDK in the experiment. To generate the auth file, run az ad sp create-for-rbac --sdk-auth > azure.auth Azure CLI command.
  • Kubernetes secret that has the auth file created in the earlier step in CHAOS_NAMESPACE. A secret file looks like:
apiVersion: v1
kind: Secret
metadata:
  name: cloud-secret
type: Opaque
stringData:
  azure.auth: |-
    {
      "clientId": "XXXXXXXXX",
      "clientSecret": "XXXXXXXXX",
      "subscriptionId": "XXXXXXXXX",
      "tenantId": "XXXXXXXXX",
      "activeDirectoryEndpointUrl": "XXXXXXXXX",
      "resourceManagerEndpointUrl": "XXXXXXXXX",
      "activeDirectoryGraphResourceId": "XXXXXXXXX",
      "sqlManagementEndpointUrl": "XXXXXXXXX",
      "galleryEndpointUrl": "XXXXXXXXX",
      "managementEndpointUrl": "XXXXXXXXX"
    }
  • If you change the secret key name (from azure.auth) please also update the AZURE_AUTH_LOCATION ENV value in the ChaosExperiment CR with the same name.

Default Validations​

info
  • The Azure instance should be in healthy state.

Fault Tunables​

Check the Fault Tunables

Mandatory Fields

Variables Description Notes
AZURE_INSTANCE_NAME Instance name of the target Azure instance For AKS nodes, the instance name is from the scale set section in Azure and not the node name from AKS node pool
RESOURCE_GROUP The resource group of the target instance

Optional Fields

Variables Description Notes
SCALE_SET Whether instance is part of Scale set Accepts "enable"/"disable". Default is "disable"
TOTAL_CHAOS_DURATION The total time duration for chaos insertion (sec) Defaults to 30s
CHAOS_INTERVAL The interval (in sec) between successive instance power off. 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 Eg. 30

Fault Examples​

Common Fault Tunables​

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

Stop Instances By Name​

It has comma separated list of instance names subject to instance stop chaos. You can tune it using the AZURE_INSTANCE_NAME environment variable.

You can use the following example to tune it:

## contains the Azure instance details
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: azure-instance-stop
    spec:
      components:
        env:
        # comma separated list of Azure instance names
        - name: AZURE_INSTANCE_NAMES
          value: 'instance-01,instance-02'
        # name of the resource group
        - name: RESOURCE_GROUP
          value: 'rg-azure'

Stop Scale Set Instances​

It has comma separated list of instance names subject to instance stop chaos that belong to Scale Set or AKS. You can tune it using the SCALE_SET environment variable.

You can use the following example to tune it:

## contains the Azure instance details for scale set instances or AKS nodes
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: azure-instance-stop
    spec:
      components:
        env:
        # comma separated list of Azure instance names
        - name: AZURE_INSTANCE_NAMES
          value: 'instance-01,instance-02'
        # name of the resource group
        - name: RESOURCE_GROUP
          value: 'rg-azure'
        # accepts enable/disable value. default is disable
        - name: SCALE_SET
          value: 'enable'