kube-image-clone-controller

Kubernetes Public Image Cache Controller

Overview

Kubernetes controller for automatically backup public images to user's registry which are used in Deployments and DaemonSets. kube-system and controller's namespaces are ignored.

Testing On MacOS

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-darwin-amd64
sudo install minikube-darwin-amd64 /usr/local/bin/minikube

# Start Cluster
minikube start

# Start Dashboard
minikube dashboard

If you're going to use local docker images for testing, use minikube for image building as follows.

1. Set the environment variables with eval $(minikube docker-env)
2. Build the image with the Docker daemon of Minikube (eg docker build -t my-image .)
3. Set the image in the pod spec like the build tag (eg my-image)
4. Set the imagePullPolicy to Never, otherwise Kubernetes will try to download the image.

Build & Push Your Own Controller

docker build -t <username>/kube-image-clone-controller:latest .

docker push <username>/kube-image-clone-controller:latest

Pull Public Image from Dockerhub

docker push testingnew123/kube-image-clone-controller:latest

Quick Start

Create the NameSpace

kubectl create namespace image-clone-namespace

Set the Target Docker Registry Credentials as a Secret

kubectl create secret --namespace=image-clone-namespace generic docker-registry-credentials \
  --from-literal=docker-server=index.docker.io \
  --from-literal=docker-username=testingnew123 \
  --from-literal=docker-password=xxxx

Kubernetes config file is prepared with necessary RBAC config to start.

kubectl apply -f .kubenates/k8s.yaml

DEMO

Stop Controller

kubectl delete -f .kubenates/k8s.yaml

NOTE: This will remove the namespace and all data associated with image-clone-controller.

Special Notes and Assumptions

1. Source Repository is properly tagged and previous tags will not be overridden.(once a tag is cloned it will not be cloned again until it remains in the target registry)
2. If latest tag is referred in the image it will always clone to the target registry.