|Type||Description||Tested K8s Platform|
|Generic||Inject Network Packet Corruption Into Application Pod||GKE, Packet(Kubeadm), EKS, Minikube, AKS > v1.6.0|
- 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
pod-network-corruptionexperiment resource is available in the cluster by
kubectl get chaosexperimentscommand. If not, install from here
- Cluster must run docker container runtime
- Application pods are healthy before chaos injection
- Application pods are healthy post chaos injection
- The application pod should be healthy once chaos is stopped. Service-requests should be served despite chaos.
- Injects packet corruption on the specified container by starting a traffic control (tc) process with netem rules to add egress packet corruption
- Corruption is injected via pumba library with command pumba netem corruption by passing the relevant network interface, packet-corruption-percentage, chaos duration and regex filter for container name
- Can test the application's resilience to lossy/flaky network
Steps to Execute the Chaos Experiment
This Chaos Experiment can be triggered by creating a ChaosEngine resource on the cluster. To understand the values to provide in a ChaosEngine specification, refer Getting Started
Follow the steps in the sections below to create the chaosServiceAccount, prepare the ChaosEngine & execute the experiment.
- 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.
Sample Rbac Manifest
apiVersion: v1 kind: ServiceAccount metadata: name: pod-network-corruption-sa namespace: default labels: name: pod-network-corruption-sa apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: pod-network-corruption-sa namespace: default labels: name: pod-network-corruption-sa rules: - apiGroups: ["","litmuschaos.io","batch"] resources: ["pods","jobs","events","pods/log","chaosengines","chaosexperiments","chaosresults"] verbs: ["create","list","get","patch","update","delete"] apiVersion: rbac.authorization.k8s.io/v1beta1 kind: RoleBinding metadata: name: pod-network-corruption-sa namespace: default labels: name: pod-network-corruption-sa roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: pod-network-corruption-sa subjects: - kind: ServiceAccount name: pod-network-corruption-sa namespace: default
- Provide the application info in
- Override the experiment tunables if desired in
- To understand the values to provided in a ChaosEngine specification, refer ChaosEngine Concepts
Supported Experiment Tunables
|NETWORK_INTERFACE||Name of ethernet interface considered for shaping traffic||Mandatory|
|TARGET_CONTAINER||Name of container which is subjected to network corruption||Mandatory|
|NETWORK_PACKET_CORRUPTION_PERCENTAGE||Packet corruption in percentage||Optional||Default (100)|
|TOTAL_CHAOS_DURATION||The time duration for chaos insertion (seconds)||Optional||Default (60000ms)|
|LIB||The chaos lib used to inject the chaos||Optional||only `pumba` supported currently|
|LIB_IMAGE||The pumba image used to run the kill command||Optional||Defaults to `gaiaadm/pumba:0.6.5`|
|RAMP_TIME||Period to wait before and after injection of chaos in sec||Optional|
|INSTANCE_ID||A user-defined string that holds metadata/info about current run/instance of chaos. Ex: 04-05-2020-9-00. This string is appended as suffix in the chaosresult CR name.||Optional||Ensure that the overall length of the chaosresult CR is still < 64 characters|
Sample ChaosEngine Manifest
apiVersion: litmuschaos.io/v1alpha1 kind: ChaosEngine metadata: name: nginx-network-chaos namespace: default spec: # It can be delete/retain jobCleanUpPolicy: 'delete' # It can be true/false annotationCheck: 'true' # It can be active/stop engineState: 'active' #ex. values: ns1:name=percona,ns2:run=nginx auxiliaryAppInfo: '' monitoring: false appinfo: appns: 'default' # FYI, To see app label, apply kubectl get pods --show-labels applabel: 'app=nginx' appkind: 'deployment' chaosServiceAccount: pod-network-corruption-sa experiments: - name: pod-network-corruption spec: components: env: #Container name where chaos has to be injected - name: TARGET_CONTAINER value: 'nginx' #Network interface inside target container - name: NETWORK_INTERFACE value: 'eth0' - name: TOTAL_CHAOS_DURATION value: '60' # in seconds
Create the ChaosEngine Resource
Create the ChaosEngine manifest prepared in the previous step to trigger the Chaos.
kubectl apply -f chaosengine.yml
If the chaos experiment is not executed, refer to the troubleshooting section to identify the root cause and fix the issues.
Watch Chaos progress
View impact of network packet corruption on the affected pod from the cluster nodes (alternate is to setup ping to a remote IP from inside the target pod)
Check Chaos Experiment Result
Check whether the application is resilient to the Pod Network Packet Corruption, once the experiment (job) is completed. The ChaosResult resource name is derived like this:
kubectl describe chaosresult <ChaosEngine-Name>-<ChaosExperiment-Name> -n <application-namespace>
Application Pod Network Packet Corruption Demo
- A sample recording of this experiment execution is provided here.