Buildah

Buildah for Dockerfile and scripted OCI image builds without a container daemon.

Build from Dockerfile

Build using a standard Dockerfile

buildah bud -t myapp:v1.0 .
buildah bud -t myapp:v1.0 -f Dockerfile.prod .     # specific Dockerfile
buildah bud --no-cache -t myapp:v1.0 .              # force rebuild
buildah bud --layers -t myapp:v1.0 .                # cache intermediate layers

Scripted Builds (No Dockerfile)

Build an image interactively with shell commands

container=$(buildah from alpine:3.19)
buildah run "$container" -- apk add --no-cache nginx
buildah copy "$container" ./nginx.conf /etc/nginx/nginx.conf
buildah config --port 80 "$container"
buildah config --entrypoint '["/usr/sbin/nginx", "-g", "daemon off;"]' "$container"
buildah commit "$container" myapp:v1.0
buildah rm "$container"

Scripted builds give you full shell control over each layer. Useful when Dockerfile syntax is limiting or when you need conditional logic during build.

Image Management

List, inspect, and push images

buildah images                          # list local images
buildah inspect myapp:v1.0              # image metadata
buildah push myapp:v1.0 docker://registry.example.com/myapp:v1.0
buildah push myapp:v1.0 oci-archive:myapp-v1.0.tar   # export to OCI archive

Tag images

buildah tag myapp:v1.0 myapp:latest
buildah tag myapp:v1.0 registry.example.com/myapp:v1.0

Working Containers

Manage build containers

buildah containers                      # list working containers
buildah rm "$container"                 # remove working container
buildah rm --all                        # remove all working containers

Mount container filesystem for direct manipulation

mnt=$(buildah mount "$container")
echo "Container root: $mnt"
cp ./app "$mnt/usr/local/bin/app"       # copy files directly
buildah unmount "$container"

Cleanup

Remove unused build artifacts

buildah prune                           # remove dangling build cache
buildah rmi --all                       # remove all local images