cki_deployment_clean_docker_images.sh

Remove old docker images on the runners

A list of images to keep is built by image ID, and all other images are removed. This correctly handles both tagged images and digest-only references (from SHA-pinned pulls like tag@sha256:...).

The following images are kept:

all :latest images
all :production images
the most recent mr-* tagged image (configurable via MR_IMAGE_TAG_COUNT)
the most recent p-* tagged image (configurable via PIPELINE_IMAGE_TAG_COUNT)
all gitlab-runner-helper images
all images currently in use by running containers

A docker image prune -f runs first to clean up dangling layers before the keep set is built. All other images (including stale digest-only references) are then removed by ID.

cki_deployment_clean_docker_images.sh

Environment variables

Field	Type	Required	Description
`CKI_DEPLOYMENT_ENVIRONMENT`	string	no	Images are only removed if set to `production`
`MR_IMAGE_TAG_COUNT`	int	no	Number of newest `mr-*` tags to keep (default: 1)
`PIPELINE_IMAGE_TAG_COUNT`	int	no	Number of newest `p-*` tags to keep (default: 1)