Installation

Details on how to install krkn and krkn-hub

1: Krkn
2: Krkn-lib
3: krkn-hub

The following ways are supported to run Krkn:

Standalone python program through Git - See specific documentation for krkn
Containerized version using either Podman or Docker as the runtime via Krkn-hub
Kubernetes or OpenShift deployment ( unsupported )

Note

It is recommended to run Kraken external to the cluster ( Standalone or Containerized ) hitting the Kubernetes/OpenShift API as running it internal to the cluster might be disruptive to itself and also might not report back the results if the chaos leads to cluster’s API server instability.

Note

To run Kraken on Power (ppc64le) architecture, build and run a containerized version by following the instructions given here.

Note

Helper functions for interactions in Krkn are part of krkn-lib. Please feel free to reuse and expand them as you see fit when adding a new scenario or expanding the capabilities of the current supported scenarios.

1 - Krkn

Krkn aka Kraken

Installation

Git

Clone the repository

$ git clone https://github.com/krkn-chaos/krkn.git --branch <release version>
$ cd krkn

Install the dependencies

$ python3.9 -m venv chaos
$ source chaos/bin/activate
$ pip3.9 install -r requirements.txt

Note

Make sure python3-devel and latest pip versions are installed on the system. The dependencies install has been tested with pip >= 21.1.3 versions.

Where can your user find your project code? How can they install it (binaries, installable package, build from source)? Are there multiple options/versions they can install and how should they choose the right one for them?

Getting Started with Krkn

If you are wanting to try to edit your config file and scenarios

Running Krkn

$ python3.9 run_kraken.py --config <config_file_location>

Run containerized version

Krkn-hub is a wrapper that allows running Krkn chaos scenarios via podman or docker runtime with scenario parameters/configuration defined as environment variables.

2 - Krkn-lib

Krkn-lib contains the base kubernetes python functions

Installation

Git

Clone the repository

git clone https://github.com/krkn-chaos/krkn-lib
cd krkn-lib

Install the dependencies

Krkn lib uses poetry for its dependency management and packaging. To install the proper packages please use:

$ pip install poetry
$ poetry install --no-interaction

Available Functions

You can find a list of available functions and modules here

Testing your changes

To see how you can configure and test your changes see testing changes

3 - krkn-hub

Krkn-hub aka kraken-hub

Hosts container images and wrapper for running scenarios supported by Krkn, a chaos testing tool for Kubernetes clusters to ensure it is resilient to failures. All we need to do is run the containers with the respective environment variables defined as supported by the scenarios without having to maintain and tweak files!

Set Up

You can use docker or podman to run kraken-hub

Install Podman your certain operating system based on these instructions

Install Docker on your system.

Docker is also supported but all variables you want to set (separate from the defaults) need to be set at the command line In the form -e <VARIABLE>=<value>

You can take advantage of the get_docker_params.sh script to create your parameters string This will take all environment variables and put them in the form “-e =” to make a long string that can get passed to the command

For example: docker run $(./get_docker_params.sh) --net=host -v <path-to-kube-config>:/home/krkn/.kube/config:Z -d quay.io/redhat-chaos/krkn-hub:power-outages

Tip

Because the container runs with a non-root user, ensure the kube config is globally readable before mounting it in the container. You can achieve this with the following commands:

kubectl config view –flatten > ~/kubeconfig && chmod 444 ~/kubeconfig && docker run $(./get_docker_params.sh) –name=<container_name> –net=host -v ~kubeconfig:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:<scenario>