image-clone-controller

Kubernetes image clone controller

Description

• It copies public docker images of Deployments & DaemonSet into backup-registry.
• It also updates the Deployments/DaemonSets to use image from backup-registry.
• Dockerfile is included in cmd/imgcc/main directory.
• deployment.yaml in the setup/makebuild directory is using docker.io/sankalprangare/image-clone-controller as image, and it also contains RBAC manifests required by the controller.
• Makefile in the setup/makebuild directory contains commands for publishing docker image, deploying and uninstalling the controller.

How to run

Note: This controller will get deployed in image-clone-controller namespace.

• Navigate to setup/makebuild directory and export REGISTRY, REGISTRY_USER and REGISTRY_PASSWORD as env variables like example below:

  • export REGISTRY=docker.io/sankalprangare
  • export REGISTRY_USER=abc
  • export REGISTRY_PASSWORD=abc123

• After the previous step, run make deploy command from Makefile, this will deploy the controller.
  Or you can also use kubectl directly, given that you replace env variables in the deployment.yaml.

• Controller will update the images of respective objects after sometime.

• To uninstall the controller run make clean.

Demo

Enhancement scope

• This simple implementation can be further improved to production-grade implementation.
• Enhancement can be made to support private-registry.
• Unit-tests can be improved to cover more cases.
• Predicates can be added to improve filtering.

References

• Controller-runtime
• go-containerregistry