Common tunables for all faults

Fault tunables common to all the faults are provided at .spec.experiment[*].spec.components.env in the chaosengine.

Duration of the chaos

Total duration of the chaos injection (in seconds). Tune it by using the TOTAL_CHAOS_DURATION environment variable.

The following YAML snippet illustrates the use of this environment variable:

# defines total time duration of the chaos
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        # time duration for the chaos execution
        - name: TOTAL_CHAOS_DURATION
          VALUE: '60'

Chaos interval

The delay between each chaos iteration. Multiple iterations of chaos are tuned by setting the CHAOS_INTERVAL environment variable.

The following YAML snippet illustrates the use of this environment variable:

# defines delay between each successive iteration of the chaos
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        # delay between each iteration of chaos
        - name: CHAOS_INTERVAL
          value: '15'
        # time duration for the chaos execution
        - name: TOTAL_CHAOS_DURATION
          VALUE: '60'

Ramp time

Period to wait before and after injecting chaos. It is in units of seconds. Tune it by using the RAMP_TIME environment variable.

The following YAML snippet illustrates the use of this environment variable:

# waits for the ramp time before and after injection of chaos
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        # waits for the time interval before and after injection of chaos
        - name: RAMP_TIME
          value: '10' # in seconds

Sequence of chaos execution

The sequence of the chaos execution for multiple targets. Its default value is parallel. Tune it by using the SEQUENCE environment variable. It supports the following modes:

• parallel: The chaos is injected in all the targets at once.
• serial: The chaos is injected in all the targets one by one.

The following YAML snippet illustrates the use of this environment variable:

# define the order of execution of chaos in case of multiple targets
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        # define the sequence of execution of chaos in case of mutiple targets
        # supports: serial, parallel. default: parallel
        - name: SEQUENCE
          value: 'parallel'

Instance ID

A user-defined string that holds metadata or information about the current run or instance of chaos. For example, 04-05-2020-9-00. This string is appended as a suffix in the chaosresult CR name. Tune it by using the INSTANCE_ID environment variable.

The following YAML snippet illustrates the use of this environment variable:

# provide to append user-defined suffix in the end of chaosresult name
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        # user-defined string appended as suffix in the chaosresult name
        - name: INSTANCE_ID
          value: '123'

Image used by the helper pod

The image used to launch the helper pod, if applicable. Tune it by using the LIB_IMAGE environment variable. It is supported by container-kill, network-faults, stress-faults, dns-faults, disk-fill, kubelet-service-kill, docker-service-kill, and node-restart faults.

The following YAML snippet illustrates the use of this environment variable:

# it contains the lib image used for the helper pod
# it support [container-kill, network-faults, stress-faults, dns-faults, disk-fill,
# kubelet-service-kill, docker-service-kill, node-restart] faults
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: container-kill
    spec:
      components:
        env:
        # name of the lib image
        - name: LIB_IMAGE
          value: 'harness/chaos-go-runner:main-latest'

Default health check

Determines if you wish to run the default health check which is present inside the fault. Its default value is 'true'. Tune it by using the DEFAULT_HEALTH_CHECK environment variable.

The following YAML snippet illustrates the use of this environment variable:

## application status check as tunable
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: pod-delete
    spec:
      components:
        env:
        - name: DEFAULT_HEALTH_CHECK
          value: 'false'