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Node Drain


  • It drain the node. The resources which are running on the target node should be reschedule on the other nodes.

Scenario: Drain the node

Node Drain


View the uses of the experiment

coming soon


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 node-drain experiment resource is available in the cluster by executing kubectl get chaosexperiments in the desired namespace. If not, install from here
  • Ensure that the node specified in the experiment ENV variable TARGET_NODE (the node which will be drained) should be cordoned before execution of the chaos experiment (before applying the chaosengine manifest) to ensure that the litmus experiment runner pods are not scheduled on it / subjected to eviction. This can be achieved with the following steps:
    • Get node names against the applications pods: kubectl get pods -o wide
    • Cordon the node kubectl cordon <nodename>

Default Validations

View the default validations

The target nodes should be in ready state before and after chaos injection.

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
  name: node-drain-sa
  namespace: default
    name: node-drain-sa litmus
kind: ClusterRole
  name: node-drain-sa
    name: node-drain-sa litmus
# 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 details and mount it to the experiment pod (if specified)
  - apiGroups: [""]
    resources: ["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","pods/eviction"]
    verbs: ["get","list","create"]
  # ignore daemonsets while draining the node
  - apiGroups: ["apps"]
    resources: ["daemonsets"]
    verbs: ["list","get","delete"]
  # 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: [""]
    resources: ["chaosengines","chaosexperiments","chaosresults"]
    verbs: ["create","list","get","patch","update","delete"]
  # for experiment to perform node status checks
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get","list","patch"]
kind: ClusterRoleBinding
  name: node-drain-sa
    name: node-drain-sa litmus
  kind: ClusterRole
  name: node-drain-sa
- kind: ServiceAccount
  name: node-drain-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

check the experiment tunables

Mandatory Fields

Variables Description Notes
TARGET_NODE Name of the node to be tainted
NODE_LABEL It contains node label, which will be used to filter the target node if TARGET_NODE ENV is not set It is mutually exclusive with the TARGET_NODE ENV. If both are provided then it will use the TARGET_NODE

Optional Fields

Variables Description Notes
TOTAL_CHAOS_DURATION The time duration for chaos insertion (seconds) Defaults to 60s
LIB The chaos lib used to inject the chaos Defaults to litmus
RAMP_TIME Period to wait before injection of chaos in sec

Experiment Examples

Common and Node specific tunables

Refer the common attributes and Node specific tunable to tune the common tunables for all experiments and node specific tunables.

Drain Node

It contains name of target node subjected to the chaos. It can be tuned via TARGET_NODE ENV.

Use the following example to tune this:

# drain the targeted node
kind: ChaosEngine
  name: engine-nginx
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: node-drain-sa
  - name: node-drain
        # name of the target node
        - name: TARGET_NODE
          value: 'node01'
        - name: TOTAL_CHAOS_DURATION
          value: '60'