Image Builder

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

Configuration

Settings

Please add this variable to the .env file.

Name	Value
PRIMEHUB_FEATURE_CUSTOM_IMAGE	true
PRIMEHUB_CUSTOM_IMAGE_REGISTRY_ENDPOINT	The registry the built image to push
PRIMEHUB_CUSTOM_IMAGE_REGISTRY_USERNAME	Login user name for registry
PRIMEHUB_CUSTOM_IMAGE_REGISTRY_PASSWORD	Login password for registry
PRIMEHUB_CUSTOM_IMAGE_REPO_PREFIX	The image prefix for the build image. The result image will be <repo prefix>/<image>:<tag>

Using GCR (Goolge Container Registry)

1. please reference this official document for GCR to get the username and password

2. The username is always _json_key. The password is the keyfile json. Please make it a one-line json string so that we can put it in the environment variable.

   cat keyfile | jq -c .
   

3. Setup the environment valuable to .env. Here is an example

   PRIMEHUB_FEATURE_CUSTOM_IMAGE=true
   PRIMEHUB_CUSTOM_IMAGE_REGISTRY_ENDPOINT=https://gcr.io
   PRIMEHUB_CUSTOM_IMAGE_REGISTRY_USERNAME=_json_key
   PRIMEHUB_CUSTOM_IMAGE_REGISTRY_PASSWORD='{"type":"service_account","project_id":....gserviceaccount.com"}'
   PRIMEHUB_CUSTOM_IMAGE_REPO_PREFIX=gcr.io/my-private-repo
   

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 exisiting 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.