Inspect image layers

See each layer, its command, and size; identify bloat

docker history --no-trunc img:tag
tool
docker46 commands
tags
dockerdebug

More docker commands

  • Prune everything unused
    docker system prune -af --volumes

    Remove stopped containers, unused images, networks, volumes

  • Copy image between registries
    docker pull src-reg/img:tag && docker tag src-reg/img:tag dst-reg/img:tag && docker push dst-reg/img:tag

    Re-tag and push to another registry

  • Save image to tarball
    docker save img:tag | gzip > img.tar.gz

    Export an image for air-gapped transfer

  • Build with build args
    docker build --build-arg VERSION=1.2.3 --build-arg ENV=prod -t img:tag .

    Pass build-time variables into Dockerfile ARG instructions

  • Scan image with Trivy
    trivy image --exit-code 1 --severity HIGH,CRITICAL img:tag

    Fail pipeline if HIGH or CRITICAL CVEs found

all 46 docker commands