Slim down docker dind:

This gets us some space back. The latest
docker was larger than the previous and udev
added some extra space.

Signed-off-by: Jacob Weinstock <[email protected]>

Author: jacobweinstock

images/hook-docker/Dockerfile

@@ -3,15 +3,22 @@ COPY . /src/
 WORKDIR /src
 RUN CGO_ENABLED=0 go build -a -ldflags '-s -w -extldflags "-static"' -o /hook-docker
 
-FROM docker:28.2.2-dind
+FROM docker:28.2.2-dind AS docker
 RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
 RUN apk update && apk add kexec-tools binutils && rm -rf /var/cache/apk/*
 # Won't use docker-buildx nor docker-compose
 RUN rm -rf /usr/local/libexec/docker/cli-plugins
 # Strip some large binaries
-RUN strip /usr/local/bin/docker /usr/local/bin/dockerd /usr/local/bin/docker-proxy /usr/local/bin/runc
+RUN strip /usr/local/bin/docker /usr/local/bin/dockerd /usr/local/bin/docker-proxy /usr/local/bin/runc /usr/local/bin/containerd /usr/local/bin/containerd-shim-runc-v2
 # Purge binutils package after stripping
 RUN apk del binutils
+
+FROM alpine:3.22
 COPY --from=dev /hook-docker .
+COPY --from=docker /usr/local/bin/docker-init /usr/local/bin/docker /usr/local/bin/dockerd /usr/local/bin/docker-proxy /usr/local/bin/runc /usr/local/bin/
+COPY --from=docker /usr/local/bin/containerd /usr/local/bin/containerd-shim-runc-v2 /usr/local/bin/
+COPY --from=docker /usr/local/bin/dockerd-entrypoint.sh /usr/local/bin/dockerd-entrypoint.sh
+
+RUN apk add --no-cache ca-certificates iptables
 
 ENTRYPOINT ["/hook-docker"]