Common tunables for node experiments

It contains tunables, which are common for all the node experiments. These tunables can be provided at .spec.experiment[*].spec.components.env in chaosengine.

Target Single Node

It defines the name of the target node subjected to chaos. The target node can be tuned via TARGET_NODE ENV. It contains only a single node name. NOTE: It is supported by [node-drain, node-taint, node-restart, kubelet-service-kill, docker-service-kill] experiments.

Use the following example to tune this:

## provide the target node name
## it is applicable for the [node-drain, node-taint, node-restart, kubelet-service-kill, docker-service-kill]
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: node-drain-sa
  experiments:
  - name: node-drain
    spec:
      components:
        env:
        # name of the target node
        - name: TARGET_NODE
          value: 'node01'
        - name: TOTAL_CHAOS_DURATION
          value: '60'

Target Multiple Nodes

It defines the comma-separated name of the target nodes subjected to chaos. The target nodes can be tuned via TARGET_NODES ENV. NOTE: It is supported by [node-cpu-hog, node-memory-hog, node-io-stress] experiments

Use the following example to tune this:

## provide the comma separated target node names
## it is applicable for the [node-cpu-hog, node-memory-hog, node-io-stress]
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: node-cpu-hog-sa
  experiments:
  - name: node-cpu-hog
    spec:
      components:
        env:
        # comma separated target node names
        - name: TARGET_NODES
          value: 'node01,node02'
        - name: TOTAL_CHAOS_DURATION
          value: '60'

Target Nodes With Labels

It defines the labels of the targeted node(s) subjected to chaos. The node labels can be tuned via NODE_LABEL ENV. It is mutually exclusive with the TARGET_NODE(S) ENV. If TARGET_NODE(S) ENV is set then it will use the nodes provided inside it otherwise, it will derive the node name(s) with matching node labels.

Use the following example to tune this:

## provide the labels of the targeted nodes
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: node-cpu-hog-sa
  experiments:
  - name: node-cpu-hog
    spec:
      components:
        env:
        # labels of the targeted node
        # it will derive the target nodes if TARGET_NODE(S) ENV is not set
        - name: NODE_LABEL
          value: 'key=value'
        - name: TOTAL_CHAOS_DURATION
          value: '60'

Node Affected Percentage

It defines the percentage of nodes subjected to chaos with matching node labels. It can be tuned with NODES_AFFECTED_PERC ENV. If NODES_AFFECTED_PERC is provided as empty or 0 then it will target a minimum of one node. It is supported by [node-cpu-hog, node-memory-hog, node-io-stress] experiments. The rest of the experiment selects only a single node for the chaos.

Use the following example to tune this:

## provide the percentage of nodes to be targeted with matching labels
## it is applicable for the [node-cpu-hog, node-memory-hog, node-io-stress]
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: node-cpu-hog-sa
  experiments:
  - name: node-cpu-hog
    spec:
      components:
        env:
        # percentage of nodes to be targeted with matching node labels
        - name: NODES_AFFECTED_PERC
          value: '100'
        # labels of the targeted node
        # it will derive the target nodes if TARGET_NODE(S) ENV is not set
        - name: NODE_LABEL
          value: 'key=value'
        - name: TOTAL_CHAOS_DURATION
          value: '60'