Image Builder

Provide a way for admin to build images with custom packages.

Design

We use a CRD ImageSpec to get specific definition of our image setup, primehub-controller will base on it to generate a CRD ImageSpecJob for an image building job, ImageSpecJob likes a revision of ImageSpec. Then the controller will convert package manifest to a Dockerfile and create a corresponding pod to build the Dockerfile through buildah. Once the status of building pod changes, it will be updated back to .status in ImageSpecJob and ImageSpec. Once the building job succeeded, the built image will be pushed to the container registry that we configured.

Image Builder spec

An ImageSpec example. You can modify .spec.baseImage value to extend existing docker image with custom packages, we support .spec.packages.apt, .spec.packages.pip and .spec.packages.conda.

Check building job status

Job's current status will update .status in ImageSpecJob and the status of the newest ImageSpecJob will be updated to ImageSpec that we created before.

Update spec and rebuild image

Primehub-controller keeps watching ImageSpecs. When you update values about .spec.baseImage, .spec.packages in ImageSpec, primehub-controller will create a new ImageSpecJob and start a new building job automatically.