litmus-docs/Versioned_docs_and_sidebars/versioned_docs/version-1.6.0/getstarted.md

id	title	sidebar_label	original_id
version-1.6.0-getstarted	Getting Started with Litmus	Introduction	getstarted

## Pre-requisites Kubernetes 1.11 or later. ## Getting Started Running chaos on your application involves the following steps: Install Litmus Install Chaos Experiments Setup Service Account Annotate your application Prepare ChaosEngine Run Chaos Observe chaos results

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### Install Litmus Apply the LitmusChaos Operator manifest: kubectl apply -f https://litmuschaos.github.io/litmus/litmus-operator-v1.6.0.yaml The above command install all the CRDs, required service account configuration, and chaos-operator. Before you start running a chaos experiment, verify if Litmus is installed correctly. Verify your installation - Verify if the chaos operator is running kubectl get pods -n litmus Expected output: >chaos-operator-ce-554d6c8f9f-slc8k 1/1 Running 0 6m41s - Verify if chaos CRDs are installed kubectl get crds | grep chaos Expected output: > chaosengines.litmuschaos.io 2019-10-02T08:45:25Z > > chaosexperiments.litmuschaos.io 2019-10-02T08:45:26Z > > chaosresults.litmuschaos.io 2019-10-02T08:45:26Z - Verify if the chaos api resources are successfully created in the desired (application) namespace. Note: Sometimes, it can take a few seconds for the resources to be available post the CRD installation kubectl api-resources | grep chaos Expected output: > chaosengines litmuschaos.io true ChaosEngine > > chaosexperiments litmuschaos.io true ChaosExperiment > > chaosresults litmuschaos.io true ChaosResult NOTE: - In this guide, we shall describe the steps to inject container-kill chaos on an nginx application already deployed in the nginx namespace. It is a mandatory requirement to ensure that the chaos custom resources (chaosexperiment and chaosengine) and the experiment specific serviceaccount are created in the same namespace (typically, the same as the namespace of the application under test (AUT), in this case nginx). This is done to ensure that the developers/users of the experiment isolate the chaos to their respective work-namespaces in shared environments. - In all subsequent steps, please follow these instructions by replacing the nginx namespace and labels with that of your application. - The chaos operator collects some usage metrics (operator installation count & experiment run count) via a google analytics hook. This is done in order to gather chaos trends that will help us to improve the project. However, if you would like to prevent the collection of the same or are operating in an airgapped environment, you can disable it using the procedure suggested here. ### Install Chaos Experiments Chaos experiments contain the actual chaos details. These experiments are installed on your cluster as Kubernetes CRs. The Chaos Experiments are grouped as Chaos Charts and are published on Chaos Hub. The generic chaos experiments such as pod-delete, container-kill, pod-network-latency are available under Generic Chaos Chart. This is the first chart you are recommended to install. kubectl apply -f https://hub.litmuschaos.io/api/chaos/1.6.0?file=charts/generic/experiments.yaml -n nginx Verify if the chaos experiments are installed. kubectl get chaosexperiments -n nginx ### Setup Service Account A service account should be created to allow chaosengine to run experiments in your application namespace. Copy the following into a rbac.yaml manifest and run kubectl apply -f rbac.yaml to create one such account on the nginx namespace. This serviceaccount has just enough permissions needed to run the container-kill chaos experiment. NOTE: - For rbac samples corresponding to other experiments such as, say, pod-delete, please refer the respective experiment folder in the chaos-charts repository. embedmd:# (https://raw.githubusercontent.com/litmuschaos/chaos-charts/master/charts/generic/container-kill/rbac_nginx_getstarted.yaml yaml) ```yaml

apiVersion: v1 kind: ServiceAccount metadata: name: container-kill-sa namespace: nginx labels: name: container-kill-sa

apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: container-kill-sa namespace: nginx labels: name: container-kill-sa rules:

• apiGroups: ["","litmuschaos.io","batch","apps"] resources: ["pods","jobs","pods/exec","pods/log","events","chaosengines","chaosexperiments","chaosresults"] verbs: ["create","list","get","patch","update","delete"]

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apiVersion: rbac.authorization.k8s.io/v1beta1 kind: RoleBinding metadata: name: container-kill-sa namespace: nginx labels: name: container-kill-sa roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: container-kill-sa subjects:

• kind: ServiceAccount name: container-kill-sa namespace: nginx

### Annotate your application

Your application has to be annotated with `litmuschaos.io/chaos="true"`. As a security measure, and also as a means
to reduce blast radius the chaos operator checks for this annotation before invoking chaos experiment(s) on the application.
Replace `nginx` with the name of your deployment.

<div class="danger">
<strong>NOTE</strong>:
Litmus supports chaos on deployments, statefulsets & daemonsets. This example refers to a nginx deploymemt. In case
of other types, please use the appropriate resource/resource-name convention (say, `sts/kafka` or `ds/node-device-manager`, for example).
</div>

```console
kubectl annotate deploy/nginx litmuschaos.io/chaos="true" -n nginx

Prepare ChaosEngine

ChaosEngine connects the application instance to a Chaos Experiment. Copy the following YAML snippet into a file called chaosengine.yaml and update the values of applabel , appns, appkind and experiments as per your choice. Change the chaosServiceAccount to the name of service account created in above previous steps.

NOTE: To learn more about the various fields in the ChaosEngine spec and their supported values, refer to Constructing ChaosEngine

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: nginx-chaos
  namespace: nginx
spec:
  # It can be true/false
  annotationCheck: 'true'
  # It can be active/stop
  engineState: 'active'
  #ex. values: ns1:name=percona,ns2:run=nginx
  auxiliaryAppInfo: ''
  appinfo:
    appns: 'nginx'
    applabel: 'app=nginx'
    appkind: 'deployment'
  chaosServiceAccount: container-kill-sa
  monitoring: false
  # It can be delete/retain
  jobCleanUpPolicy: 'delete'
  experiments:
    - name: container-kill
      spec:
        components:
          env:
            # specify the name of the container to be killed
            - name: TARGET_CONTAINER
              value: 'nginx'

            # provide the chaos interval
            - name: CHAOS_INTERVAL
              value: '10'

            # provide the total chaos duration
            - name: TOTAL_CHAOS_DURATION
              value: '20'

            # For containerd image use: litmuschaos/container-kill-helper:latest
            - name: LIB_IMAGE
              value: 'gaiaadm/pumba:0.6.5'

            # It supports pumba and containerd
            - name: LIB
              value: 'pumba'

Override Default Chaos Experiments Variables

From LitmusChaos v1.1.0, the default environment variable values in chaosexperiments can be overridden by specifying them in the chaosengine under experiments.<experiment_name>.spec.components.env with the desired value. In the example below, the TARGET_CONTAINER is being set to a desired value based on the application instance.

...
experiments:
    - name: container-kill
      spec:
        components:
          env:
            - name: TARGET_CONTAINER
              value: nginx

Run Chaos

Apply the ChaosEngine manifest to trigger the experiment.

kubectl apply -f chaosengine.yaml

Observe Chaos results

Describe the ChaosResult CR to know the status of each experiment. The status.verdict is set to Awaited when the experiment is in progress, eventually changing to either Pass or Fail.

NOTE: ChaosResult CR name will be <chaos-engine-name>-<chaos-experiment-name>

kubectl describe chaosresult nginx-chaos-container-kill -n nginx

Uninstallation

Firstly, delete any active ChaosEngines on the cluster, followed by the deletion of the Operator manifest.

kubectl delete chaosengine --all -n <namespace>

kubectl delete -f https://litmuschaos.github.io/litmus/litmus-operator-v1.6.0.yaml

NOTE

• Ensure that the chaosengine resources are deleted before removal of the chaos-operator deployment via operator manifest. Failure to do so can cause the uninstall operation to be "stuck". Refer to the these steps to resolve this condition and complete the uninstall.

Troubleshooting

For any issues experienced in running through the the aforementioned steps, refer to the Troubleshooting section.

More Chaos Experiments

• For more details on supported chaos experiments and the steps to run them, refer the respective Experiment docs.

Join our community

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