ktune

Kubernetes Applications Auto-tuning

For example, ktune watches image repository for new images, and triggers canary deployments in k8s. It makes sure you are always running the latest images in your deployments.

Build

You need glide

You will first need a working go build environment set up. See here for advice

Clone the repo and make

$ git clone https://github.com/skippbox/ktune
$ glide install
$ make build

Example

Create a deployment that you consider stable and give it a label to identify it, for example in a single command:

$ kubectl run hostname --image=runseb/hostname:0.1.0 --labels="run=hostname,track=stable"

Start ktune, it will check the deployment and realize that there is an image on the Docker hub with the tag latest, it will generate a canary deployment.

$ ./ktune --debug
INFO[0000] Starting ktune
INFO[0000] Worker iteration at 2016-10-17 15:19:58.655875145 +0200 CEST
INFO[0010] Checking Deployment 'hostname'
INFO[0011] Latest tag found to be ''
INFO[0011] image '[runseb/hostname 0.1.0]' is outdated. New canary will update to 'runseb/hostname:latest'
INFO[0011] Creating new deployment 'hostname-ktune'

Check your deployments and resulting pods:

$ kubectl get deployments --show-labels
NAME             DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE       LABELS
hostname         1         1         1            1           26m       run=hostname,track=stable
hostname-ktune   1         1         1            1           5s        run=hostname,track=canary
$ kubectl get pods
NAME                             READY     STATUS    RESTARTS   AGE
hostname-3656820496-fztby        1/1       Running   0          31m
hostname-ktune-969058483-k16wj   1/1       Running   0          4m

WIP

For now, ktune will:

• Reads kubeconfig file and checks RCs images
• Looks for images on docker hub (other repos not yet supported)
• Uses basic tag comparison to detect whether the tag being used is the latest
• Read images used by Deployments
• Creates canary deployment

Still doesn't ...

• Use patterns to indicate which images should be updated
• Use patterns to indicate which tags are latest
• Support gcr.io or quay.io

Usage

Use ./ktune -h to get usage

ktune expect a container version tag that can be machine compared, following the pattern Major.Minor.Build-Revision

To get the latest image version, grisou:

1. Divides the tag string in dots
2. Keep the first 3 groups, discarding the rest
3. In each group get the first number, dicarding letters or symbols
4. In the last group, looks for a minus symbol, and tries to read a number to the right

Examples:

• 1.2
• v1.2
• 1.2.3
• 1.2.3-4
• v1.b.2.g3-4 equals - 1.2.3-4
• latest is considered latest version.