chaostoolkit-k8s-wix

This is extended version of Chaos Toolkit Kubernetes Support

Created to provide more flexibility with experiments

This project contains activities, such as probes and actions, you can call from your experiment through the Chaos Toolkit.

Install

To be used from your experiment, this package must be installed in the Python environment where chaostoolkit already lives.

$ pip install chaostoolkit-k8s-wix

Usage

To use the probes and actions from this package, add the following to your experiment file:

{
    "name": "all-our-microservices-should-be-healthy",
    "provider": {
        "type": "python",
        "module": chaosk8s_wix,
        "func": "microservice_available_and_healthy",
        "arguments": {
            "name": "myapp",
            "ns": "myns"
        }
    }
},
{
    "type": "action",
    "name": "terminate-db-pod",
    "provider": {
        "type": "python",
        "module": chaosk8s_wix,
        "func": "terminate_pods",
        "arguments": {
            "label_selector": "app=my-app",
            "name_pattern": "my-app-[0-9]$",
            "rand": true,
            "ns": "default"
        }
    },
    "pauses": {
        "after": 5
    }
}

That's it! Notice how the action gives you the way to kill one pod randomly.

Please explore the code to see existing probes and actions.

Discovery

You may use the Chaos Toolkit to discover the capabilities of this extension:

$ chaos discover chaostoolkit-k8s-wix --no-install

Configuration

This extension to the Chaos Toolkit can use the Kubernetes configuration found at the usual place in your HOME directory under ~/.kube/, or, when run from a Pod in a Kubernetes cluster, it will use the local service account. In that case, make sure to set the CHAOSTOOLKIT_IN_POD environment variable to "true".

You can also pass the credentials via secrets as follows:

{
    "secrets": {
        "kubernetes": {
            "KUBERNETES_HOST": "http://somehost",
            "KUBERNETES_API_KEY": {
                "type": "env",
                "key": "SOME_ENV_VAR"
            }
        }
    }
}

Then in your probe or action:

{
    "name": "all-our-microservices-should-be-healthy",
    "provider": {
        "type": "python",
        "module": chaosk8s_wix,
        "func": "microservice_available_and_healthy",
        "secrets": ["kubernetes"],
        "arguments": {
            "name": "myapp",
            "ns": "myns"
        }
    }
}

You may specify the Kubernetes context you want to use as follows:

{
    "secrets": {
        "kubernetes": {
            "KUBERNETES_CONTEXT": "minikube"
        }
    }
}

Or via the environment:

$ export KUBERNETES_CONTEXT=minikube

In the same spirit, you can specify where to find your Kubernetes configuration with:

$ export KUBECONFIG=some/path/config

Contribute

If you wish to contribute more functions to this package, you are more than welcome to do so. Please fork this project, make your changes following the usual PEP 8 code style, add appropriate tests and submit a PR for review.

The Chaos Toolkit projects require all contributors must sign a Developer Certificate of Origin on 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.

Develop

If you wish to develop on this project, make sure to install the development dependencies. But first, create a virtual environment and then install those dependencies.

$ pip install -r requirements-dev.txt -r requirements.txt 

Then, point your environment to this directory:

$ python setup.py develop

Now, you can edit the files and they will be automatically be seen by your environment, even when running from the chaos command locally.

Test

To run the tests for the project execute the following:

$ pytest