K8S Sidecar Controller

A simple kubernetes controller which ensures proper termination of sidecar containers

Tested on

• go v1.17
• Kubernetes 1.19

Usage

1. Deploy this controller. See How to deploy
2. Add an annotation to pods which have sidecar containers. Annotation format is limgit/sidecars: <sidecar>,<container>,<name>

# Example pod configuration.
# After `main` container finishes,
# the sidecar controller will send SIGTERM to `sidecar` container
apiVersion: v1
kind: Pod
metadata:
  name: busybox-sleep
  namespace: default
  annotations:
    limgit/sidecars: sidecar
spec:
  containers:
  - name: sidecar
    image: busybox
    args:
    - sleep
    - "1000000"
  - name: main
    image: busybox
    args:
    - sleep
    - "20"

3. Tada! This controller will clean up sidecar containers if every containers but sidecar containers are completed!

How to deploy

1. Build docker image with Dockefile
2. Push docker image to image repository
3. In deployment.yaml, set correct image tag for Deployment resource
4. kubectl apply -f deployment.yaml