EBS Loss By ID
- It causes chaos to disrupt state of ebs volume by detaching it from the node/ec2 instance for a certain chaos duration using volume id.
- In case of EBS persistent volumes, the volumes can get self-attached and experiment skips the re-attachment step. Tests deployment sanity (replica availability & uninterrupted service) and recovery workflows of the application pod.
Scenario: Detach EBS Volume
View the uses of the experiment
Verify the prerequisites
- Ensure that Kubernetes Version > 1.16
- Ensure that the Litmus Chaos Operator is running by executing
kubectl get podsin operator namespace (typically,
litmus).If not, install from here
- Ensure that the
ebs-loss-by-idexperiment resource is available in the cluster by executing
kubectl get chaosexperimentsin the desired namespace. If not, install from here
- Ensure that you have sufficient AWS access to attach or detach an ebs volume for the instance.
Ensure to create a Kubernetes secret having the AWS access configuration(key) in the
CHAOS_NAMESPACE. A sample secret file looks like:
apiVersion: v1 kind: Secret metadata: name: cloud-secret type: Opaque stringData: cloud_config.yml: |- # Add the cloud AWS credentials respectively [default] aws_access_key_id = XXXXXXXXXXXXXXXXXXX aws_secret_access_key = XXXXXXXXXXXXXXX
If you change the secret key name (from
cloud_config.yml) please also update the
AWS_SHARED_CREDENTIALS_FILEENV value on
experiment.yamlwith the same name.
View the default validations
- EBS volume is attached to the instance.
Minimal RBAC configuration example (optional)¶
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: ebs-loss-by-id-sa namespace: default labels: name: ebs-loss-by-id-sa app.kubernetes.io/part-of: litmus --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: ebs-loss-by-id-sa labels: name: ebs-loss-by-id-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: ebs-loss-by-id-sa labels: name: ebs-loss-by-id-sa app.kubernetes.io/part-of: litmus roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: ebs-loss-by-id-sa subjects: - kind: ServiceAccount name: ebs-loss-by-id-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.
check the experiment tunables
|EBS_VOLUME_ID||Comma separated list of volume IDs subjected to ebs detach chaos|
|REGION||The region name for the target volumes|
|TOTAL_CHAOS_DURATION||The time duration for chaos insertion (sec)||Defaults to 30s|
|CHAOS_INTERVAL||The time duration between the attachment and detachment of the volumes (sec)||Defaults to 30s|
|SEQUENCE||It defines sequence of chaos execution for multiple volumes||Default value: parallel. Supported: serial, parallel|
|RAMP_TIME||Period to wait before and after injection of chaos in sec|
Common and AWS specific tunables¶
Detach Volumes By ID¶
It contains comma separated list of volume IDs subjected to ebs detach chaos. It can be tuned via
Use the following example to tune this:
# contains ebs volume id apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: engine-nginx spec: engineState: "active" annotationCheck: "false" chaosServiceAccount: ebs-loss-by-id-sa experiments: - name: ebs-loss-by-id spec: components: env: # id of the ebs volume - name: EBS_VOLUME_ID value: 'ebs-vol-1' # region for the ebs volume - name: REGION value: '<region for EBS_VOLUME_ID>' - name: TOTAL_CHAOS_DURATION VALUE: '60'