mirantis/k8s-daemonupgradecontroller repository overview

⁠ Daemon Set upgrade controller

Controller which manages Kubernetes DaemonSet upgrades. It stores history using PodTemplates, allows rollback to previous version and pause the upgrade process.

⁠Getting Started

⁠Installing

Daemon upgrade controller can be started as a docker container inside of the Kubernetes cluster.

Create new file called controller.yml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: daemonupgrader
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: daemonupgrader
    spec:
      containers:
      - name: daemonupgrader
        image: mirantis/k8s-daemonupgradecontroller:latest
        imagePullPolicy: IfNotPresent

and start the container: kubectl --namespace kube-system -f controller.yml

⁠Usage

All configuration is done by setting options in daemon annotations.

By default upgrade controller will not touch the running daemons. To enable upgrades, strategy type needs to be set:

daemonset.kubernetes.io/strategyType: "RollingUpdate"

from now on whenever Spec.Template is changed upgrade controller will delete old pods and new pods with new template will be created. By default controller deletes one pod at the time and waits for new to be in Ready state. It can by configured by setting how many pods can be unavailable during the upgrade:

daemonset.kubernetes.io/maxUnavailable: "1"

⁠All configuration options

⁠daemonset.kubernetes.io/paused

When set to "true" or "1" it pauses upgrades.

⁠daemonset.kubernetes.io/rollbackTo

Sets the revision number to which rollback. When rollback is done it's set to empty string.

⁠daemonset.kubernetes.io/strategyType

For now two strategies are supported:

• RollingUpdate - deletes old pods and waiting for new to be created. By default it deletes one pod at the time.
• Noop - does nothing.

⁠daemonset.kubernetes.io/maxUnavailable

Sets how many pods can be deleted in one step during the upgrade. Default: 1.

⁠Building from source

⁠Rquirements

• make
• golang
• docker
• git
• mercurial
• configured go environemnt

Put this project in the $GOPATH

⁠Building

make build

⁠docker image

make build-image

⁠Running unit tests

make unit

⁠Running e2e tests

Start container with daemon upgrade controller. Make sure that it can connect to Kubernetes cluster. If kubernetes dind cluster⁠ is used then container can be started using docker-compos.yaml⁠ file.

make e2e

⁠Authors

Łukasz Oleś, github: lukaszo, IRC: salmon_, k8s slack: lukaszo

⁠License

Apache 2.0 License