Package: chaostoolkit-kubernetes
Chaos Toolkit Extensions for KubernetesThis project contains activities, such as probes and actions, you can call from
your experiment through the Chaos Toolkit to perform Chaos Engineering against
the Kubernetes API: killing a pod, removing a statefulset or node...InstallTo be used from your experiment, this package must be installed in the Python
environment wherechaostoolkitalready lives.$ pip install chaostoolkit-kubernetesUsageTo use the probes and actions from this package, add the following to your
experiment file:{"title":"Do we remain available in face of pod going down?","description":"We expect Kubernetes to handle the situation gracefully when a pod goes down","tags":["kubernetes"],"steady-state-hypothesis":{"title":"Verifying service remains healthy","probes":[{"name":"all-our-microservices-should-be-healthy","type":"probe","tolerance":true,"provider":{"type":"python","module":"chaosk8s.probes","func":"microservice_available_and_healthy","arguments":{"name":"myapp"}}}]},"method":[{"type":"action","name":"terminate-db-pod","provider":{"type":"python","module":"chaosk8s.pod.actions","func":"terminate_pods","arguments":{"label_selector":"app=my-app","name_pattern":"my-app-[0-9]$","rand":true}},"pauses":{"after":5}}]}That's it! Notice how the action gives you the way to kill one pod randomly.Please explore thedocumentationto see existing probes and actions.Low level fault injectionsNote, for the network, cpu and memory stressors we rely on the fantasticChaos Mesh projectthat provides a great interface
to inject these faults.You will need to install Chaos Mesh first in your cluster to use them.ConfigurationUse ~/.kube/configIf you have a valid entry in your~/.kube/configfile for the cluster you
want to target, then there is nothing to be done.You may specifyKUBECONFIGto specify a different location.$ export KUBECONFIG=/tmp/my-configSpecify the Kubernetes contextQuite often, your Kubernetes configuration contains several entries and you
need to define the one to use as a default context when not it isn't
explicitely provided.You may of course change your default usingkubectl config use-context KUBERNETES_CONTEXTbut you can also be explicit
in your experiment as follows:{"title":"Do we remain available in face of pod going down?","description":"We expect Kubernetes to handle the situation gracefully when a pod goes down","tags":["kubernetes"],"secrets":{"k8s":{"KUBERNETES_CONTEXT":"..."}},"steady-state-hypothesis":{"title":"Verifying service remains healthy","probes":[{"name":"all-our-microservices-should-be-healthy","type":"probe","tolerance":true,"secrets":["k8s"],"provider":{"type":"python","module":"chaosk8s.probes","func":"microservice_available_and_healthy","arguments":{"name":"myapp"}}}]},"method":[{"type":"action","name":"terminate-db-pod","secrets":["k8s"],"provider":{"type":"python","module":"chaosk8s.pod.actions","func":"terminate_pods","arguments":{"label_selector":"app=my-app","name_pattern":"my-app-[0-9]$","rand":true}},"pauses":{"after":5}}]}You need to specify theKUBERNETES_CONTEXTsecret key to the name of the
context you want the experiment to use. Make sure to also inform the
actions and probes about the secret entries they should be
passed"secrets": ["k8s"].Use a Pod's service accountWhen running from a pod (not your local machine or a CI for instance), the./.kube/configfile does not exist. Instead, the credentials can be found
at/var/run/secrets/kubernetes.io/serviceaccount/token.To let the extension know about this, simply setCHAOSTOOLKIT_IN_PODfrom the
environment variable of the pod specification:env:-name:CHAOSTOOLKIT_IN_PODvalue:"true"Pass all credentials in the experimentFinally, you may pass explicitely all required credentials information to the
experiment as follows:Using an API key{"secrets":{"kubernetes":{"KUBERNETES_HOST":"http://somehost","KUBERNETES_API_KEY":{"type":"env","key":"SOME_ENV_VAR"}}}}Using a username/password{"secrets":{"kubernetes":{"KUBERNETES_HOST":"http://somehost","KUBERNETES_USERNAME":{"type":"env","key":"SOME_ENV_VAR"},"KUBERNETES_PASSWORD":{"type":"env","key":"SOME_ENV_VAR"}}}}Using a TLS key/certificate{"secrets":{"kubernetes":{"KUBERNETES_HOST":"http://somehost","KUBERNETES_CERT_FILE":{"type":"env","key":"SOME_ENV_VAR"},"KUBERNETES_KEY_FILE":{"type":"env","key":"SOME_ENV_VAR"}}}}Managed Kubernetes Clusters AuthenticationOn some managed Kubernetes clusters, you also need to authenticate against the
platform itself because the Kubernetes authentication is delegated to it.Google Cloud PlatformIn addition to your Kubernetes credentials (via the~/.kube/configfile), you
need to authenticate against the Google Cloud Platform itself. Usually this
is donevia:$ gcloud auth loginBut can also be achieved by defining theGOOGLE_APPLICATION_CREDENTIALSenvironment variable.ContributeIf you wish to contribute more functions to this package, you are more than
welcome to do so. Please, fork this project, write unit tests to cover the proposed changes,
implement the changes, ensure they meet the formatting standards set out byblack,flake8, andisort, and then raise a PR to the repository for review.Please refer to theformattingsection for more information
on the formatting standards.The Chaos Toolkit projects require all contributors must sign aDeveloper Certificate of Originon each commit they would like to merge
into the master branch of the repository. Please, make sure you can abide by
the rules of the DCO before submitting a PR.DevelopIf you wish to develop on this project, make sure to install the development
dependencies. But first,create a virtual environmentand then install
those dependencies.$makeinstall-devNow, you can edit the files and they will be automatically be seen by your
environment, even when running from thechaoscommand locally.TestsTo run the tests for the project execute the following:$maketestsFormatting and LintingWe use a combination ofblack,flake8, andisortto both
lint and format this repositories code.Before raising a Pull Request, we recommend you run formatting against your code with:$makeformatThis will automatically format any code that doesn't adhere to the formatting standards.As some things are not picked up by the formatting, we also recommend you run:$makelintTo ensure that any unused import statements/strings that are too long, etc. are also picked up.