A dangling image is a container image left without a repository name or tag after a newer image supersedes it. Podman displays it as <none> <none> while retaining its image ID in local storage. section 2.2.2 section 2.3.2
Use the image ID to manage a dangling image:
- Restore a usable name with podman tag if the replacement fails. section 2.3.2
- Remove it explicitly with podman rmi when it is no longer needed. section 2.3.2
- Remove dangling images in bulk with podman image prune; use --all only when broader unused-image removal is intended. section 2.2.7
Automated replacement
Running podman build -t quay.io/rhatdan/myimage ./myapp replaces the tag on the newer image and leaves the previous image listed as <none> <none>. Repeated builds can waste storage until pruning removes the obsolete images. section 2.3.2
$ podman images REPOSITORY TAG IMAGE ID CREATED SIZE localhost/myimage latest 2c7e43d88038 46 hours ago 462 MB registry.access.redhat .com/ubi8/httpd-24 latest 8594be0a0b57 5 weeks ago 462 MB registry.access.redhat .com/ubi8 latest ad42391b9b46 5 weeks ago 234 MB
Inspect repository, tag, image ID, creation time, and size with podman images; use --all to include images not currently in use. section 2.2.2
