Skip to main content

Common Tunables for All Faults

Fault tunables common to all chaos faults are provided at .spec.experiment[*].spec.components.env in the ChaosEngine specification. These tunables control the basic execution behavior of chaos experiments.

Core Tunables​

Duration of the Chaos​

Total duration of the chaos injection in seconds. Configure using the TOTAL_CHAOS_DURATION environment variable.

Default: 30 seconds

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: TOTAL_CHAOS_DURATION
          value: '60'

Chaos Interval​

The delay between each chaos iteration in seconds. Configure using the CHAOS_INTERVAL environment variable.

Default: 10 seconds

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: CHAOS_INTERVAL
          value: '15'
        - name: TOTAL_CHAOS_DURATION
          value: '60'

Ramp Time​

Period to wait before and after injecting chaos in seconds. Configure using the RAMP_TIME environment variable.

Default: 0 seconds

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: RAMP_TIME
          value: '10'

Execution Control​

Sequence of Chaos Execution​

The sequence of chaos execution for multiple targets. Configure using the SEQUENCE environment variable.

Default: parallel

Options:

  • parallel: Chaos is injected in all targets simultaneously
  • serial: Chaos is injected in targets one by one
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: SEQUENCE
          value: 'parallel'

Instance ID​

A user-defined string that holds metadata about the current chaos run. This string is appended as a suffix in the ChaosResult CR name. Configure using the INSTANCE_ID environment variable.

Default: Empty string

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: INSTANCE_ID
          value: '123'

Advanced Configuration​

Helper Pod Image​

The container image used to launch helper pods for fault execution. Configure using the LIB_IMAGE environment variable.

Default: harness/chaos-go-runner:main-latest

Supported Faults: container-kill, network-faults, stress-faults, dns-faults, disk-fill, kubelet-service-kill, docker-service-kill, node-restart

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: container-kill
    spec:
      components:
        env:
        - name: LIB_IMAGE
          value: 'harness/chaos-go-runner:main-latest'

Default Health Check​

Determines whether to run the default health check included with the fault. Configure using the DEFAULT_HEALTH_CHECK environment variable.

Default: true

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: DEFAULT_HEALTH_CHECK
          value: 'false'

Status Check Timeout​

Maximum duration the chaos experiment will wait for a resource to reach the desired state before proceeding. If the resource doesn't attain the expected state within this timeframe, the experiment may be marked as failed.

Default: 180 seconds

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  experiments:
  - name: pod-delete
    spec:
      components:
        statusCheckTimeouts:
          delay: 2
          timeout: 300

Summary​

These common tunables provide fine-grained control over chaos fault execution. Use them to:

  • Control timing: Set duration, intervals, and ramp times
  • Manage execution: Configure sequence and health checks
  • Customize behavior: Set instance IDs and helper images
  • Ensure reliability: Configure appropriate timeouts

For fault-specific tunables, refer to the individual fault documentation in each category.