Docker

Prune a stale Docker image cache

Reclaim disk space from dangling images and build cache without touching running containers.

Dangling images only

Safe to run at any time — this only removes images with no tag, which are almost always leftover build layers:

bash

docker image prune

More aggressive: also removes tagged images that no container currently uses.

bash

docker system prune -a

bash

docker builder prune --filter until=168h

until takes a duration — 168h prunes build cache older than a week.

Tech Notes

Reference notes, grouped by technology, found by search rather than by memory.

Undo a rebase

Get a branch back to where it was before an interactive rebase went wrong.