Project: Litmus (Observability and Analysis / Chaos Engineering)
File: azure-instance-stop.md

It causes PowerOff an Azure instance before bringing it back to running state after the specified chaos duration. It helps to check the performance of the application/process running on the instance. !!! tip "Scenario: Stop the azure instance" ??? info "View the uses of the experiment" coming soon ??? info "Verify the prerequisites" Ensure that Kubernetes Version > 1.16 Ensure that the Litmus Chaos Operator is running by executing <code>kubectl get pods</code> in operator namespace (typically, <code>litmus</code>).If not, install from <a href="https://v1-docs.litmuschaos.io/docs/getstarted/#install-litmus">here</a> Ensure that the <code>azure-instance-stop</code> experiment resource is available in the cluster by executing <code>kubectl get chaosexperiments</code> in the desired namespace. If not, install from <a href="https://hub.litmuschaos.io/api/chaos/master?file=faults/azure/azure-instance-stop/fault.yaml">here</a> Ensure that you have sufficient Azure access to stop and start the an instance. We will use azure to connect with the instance using azure GO SDK in the experiment. For generating auth file run `az ad sp create-for-rbac --sdk-auth > azure.auth` Azure CLI command. Ensure to create a Kubernetes secret having the auth file created in the step in `CHAOS_NAMESPACE`. A sample secret file looks like: ```yaml 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 `AZUREAUTHLOCATION` ENV value on `experiment.yaml`with the same name. ??? info "View the default validations" Azure instance should be in healthy state. !!! 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 RBAC, which is pre installed in the cluster as part of the agent setup. ??? note "View the Minimal RBAC permissions" ```yaml apiVersion: v1 kind: ServiceAccount metadata: name: azure-instance-stop-sa namespace: default labels: name: azure-instance-stop-sa app.kubernetes.io/part-of: litmus apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: azure-instance-stop-sa labels: name: azure-instance-stop-sa app.kubernetes.io/part-of: litmus rules: apiGroups: [""] resources: ["pods"] verbs: ["create","delete","get","list","patch","update", "deletecollection"] apiGroups: [""] resources: ["events"] verbs: ["create","get","list","patch","update"] apiGroups: [""] resources: ["secrets","configmaps"] verbs: ["get","list",] apiGroups: [""] resources: ["pods/log"] verbs: ["get","list","watch"] apiGroups: [""] resources: ["pods/exec"] verbs: ["get","list","create"] apiGroups: ["batch"] resources: ["jobs"] verbs: ["create","list","get","delete","deletecollection"] apiGroups: ["litmuschaos.io"] resources: ["chaosengines","chaosexperiments","chaosresults"] verbs: ["create","list","get","patch","update","delete"] apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: azure-instance-stop-sa labels: name: azure-instance-stop-sa app.kubernetes.io/part-of: litmus roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: azure-instance-stop-sa subjects: kind: ServiceAccount name: azure-instance-stop-sa namespace: default ``` Use this sample RBAC manifest to create a chaosServiceAccount in the desired (app)

This example consists of the minimum necessary role permissions to execute the experiment. ??? info "check the experiment tunables" <h2>Mandatory Fields</h2> <table> <tr> <th> Variables </th> <th> Description </th> <th> Notes </th> </tr> <tr> <td> AZUREINSTANCENAMES </td> <td> Instance name of the target azure instance</td> <td> For AKS nodes, the instance name is from the scale set section in Azure and not the node name from AKS node pool </td> </tr> <tr> <td> RESOURCE_GROUP </td> <td> The resource group of the target instance</td> <td> </td> </tr> </table> <h2>Optional Fields</h2> <table> <tr> <th> Variables </th> <th> Description </th> <th> Notes </th> </tr> <tr> <td> SCALE_SET </td> <td> Whether instance is part of Scale set</td> <td> Accepts "enable"/"disable". Default is "disable"</td> </tr> <tr> <td> TOTALCHAOSDURATION </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 power off.</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> Refer the to tune the common tunables for all the experiments. It contains comma separated list of instance names subjected to instance stop chaos. It can be tuned via `AZUREINSTANCENAME` ENV. Use the following example to tune this: ```yaml apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: engine-nginx spec: engineState: "active" annotationCheck: "false" chaosServiceAccount: azure-instance-stop-sa experiments: name: azure-instance-stop spec: components: env: name: AZUREINSTANCENAMES value: 'instance-01,instance-02' name: RESOURCE_GROUP value: '<resource group of AZUREINSTANCENAME>' name: TOTALCHAOSDURATION value: '60' ``` It contains comma separated list of instance names subjected to instance stop chaos belonging to Scale Set or AKS. It can be tuned via `SCALE_SET` ENV. Use the following example to tune this: ```yaml apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: engine-nginx spec: engineState: "active" annotationCheck: "false" chaosServiceAccount: azure-instance-stop-sa experiments: name: azure-instance-stop spec: components: env: name: AZUREINSTANCENAMES value: 'instance-01,instance-02' name: RESOURCE_GROUP value: '<resource group of Scale set>' name: SCALE_SET value: 'enable' name: TOTALCHAOSDURATION value: '60' ``` The multiple iterations of chaos can be tuned via setting `CHAOS_INTERVAL` ENV. Which defines the delay between each iteration of chaos. Use the following example to tune this: ```yaml apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: engine-nginx spec: engineState: "active" annotationCheck: "false" chaosServiceAccount: azure-instance-stop-sa experiments: name: azure-instance-stop spec: components: env: name: CHAOS_INTERVAL value: '10' name: TOTALCHAOSDURATION value: '60' name: AZUREINSTANCENAMES value: 'instance-01,instance-02' name: RESOURCE_GROUP value: '<resource group of AZUREINSTANCENAME>' ```