kube-monkey is an implementation of Netflix's Chaos Monkey for Kubernetes clusters. It randomly deletes Kubernetes pods in the cluster encouraging and validating the development of failure-resilient services.
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kube-monkey runs at a pre-configured hour (run_hour, defaults to 8am) on weekdays, and builds a schedule of deployments that will face a random
Pod death sometime during the same day. The time-range during the day when the random pod Death might occur is configurable and
defaults to 10am to 4pm.
kube-monkey can be configured with a list of namespaces to blacklist - any deployments within a blacklisted namespace will not be touched.
kube-monkey works on an opt-in model and will only schedule terminations for Deployments that have explicitly agreed to have their pods terminated by kube-monkey.
Opt-in is done by setting the following labels on a Kubernetes Deployment:
kube-monkey/enabled: Set to "enabled" to opt-in to kube-monkey
kube-monkey/mtbf: Mean time between failure (in days). For example, if set to "3", the Deployment can expect to have a Pod
killed approximately every third weekday.
kube-monkey/identifier: A unique identifier for the deployment (eg. the deployment's name). This is used to identify the pods
that belong to a Deployment as Pods inherit labels from their Deployment.
kube-monkey/kill-all: Set this label's value to "kill-all" if you want kube-monkey to kill ALL of your pods. Default behavior in the absence of this label is to kill only ONE pod. Use this label carefully.
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: monkey-victim
namespace: app-namespace
spec:
template:
metadata:
labels:
kube-monkey/enabled: enabled
kube-monkey/identifier: monkey-victim
kube-monkey/mtbf: '2'
[... omitted ...]Scheduling happens once a day on Weekdays - this is when a schedule for terminations for the current day is generated.
During scheduling, kube-monkey will:
- Generate a list of eligible deployments (deployments that have opted-in and are not blacklisted)
- For each eligible deployment, flip a biased coin (bias determined by
kube-monkey/mtbf) to determine if a pod for that deployment should be killed today - For each victim, calculate a random time when a pod will be killed
This is the randomly generated time during the day when a victim Deployment will have a pod killed.
At termination time, kube-monkey will:
- Check if the deployment is still eligible (has not opted-out or been blacklisted since scheduling)
- Get a list of running pods for the deployment
- Select one random pod and delete it
Clone the repository and build the container.
$ go get github.com/asobti/kube-monkey
$ cd $GOPATH/src/github.com/asobti/kube-monkey
$ make container
kube-monkey is configured by a toml file placed at /etc/kube-monkey/config.toml.
Configuration keys and descriptions can be found in config/param/param.go
[kubemonkey]
dry_run = true # Terminations are only logged
run_hour = 8 # Run scheduling at 8am on weekdays
start_hour = 10 # Don't schedule any pod deaths before 10am
end_hour = 16 # Don't schedule any pod deaths after 4pm
blacklisted_namespaces = ["kube-system"] # Critical deployments live hereRun kube-monkey as a Deployment within the Kubernetes cluster, in a namespace that has permissions to kill Pods
in other namespaces (eg. kube-system).
See dir examples/ for example Kubernetes yaml files.
kube-monkey uses glog and supports all command-line features for glog. To specify a custom v level or a custom log directory on the pod, see args: ["-v=5", "-log_dir=/path/to/custom/log"] in the example deployment file
kube-monkey is built using v1.5 of kubernetes/client-go. Refer to the Compatibility Matrix to see which versions of Kubernetes are compatible.
- Add tests
- Use a logging library like glog