FROM alpine:3.5

# Docker daemon only minimal Alpine install

# set up subuid/subgid so that "--userns-remap=default" works out-of-the-box
RUN set -x \
	&& addgroup -S dockremap \
	&& adduser -S -G dockremap dockremap \
	&& echo 'dockremap:165536:65536' >> /etc/subuid \
	&& echo 'dockremap:165536:65536' >> /etc/subgid

# https://github.com/docker/docker/blob/master/project/PACKAGERS.md#runtime-dependencies
RUN apk add --no-cache \
	ca-certificates \
	curl \
	iptables \
	xz

# removed xfsprogs e2fs btrfs as we do not support dm or btrfs yet
# removed openssl as I do not think server needs it

ENV DOCKER_BUCKET get.docker.com
ENV DOCKER_VERSION 17.03.0-ce
ENV DOCKER_SHA256 4a9766d99c6818b2d54dc302db3c9f7b352ad0a80a2dc179ec164a3ba29c2d3e

# we could avoid installing client here I suppose
RUN set -x \
	&& curl -fSL "https://${DOCKER_BUCKET}/builds/Linux/x86_64/docker-${DOCKER_VERSION}.tgz" -o docker.tgz \
	&& echo "${DOCKER_SHA256} *docker.tgz" | sha256sum -c - \
	&& tar -xzvf docker.tgz \
	&& mv docker/* /usr/bin/ \
	&& rmdir docker \
	&& rm docker.tgz \
	&& docker -v

ENTRYPOINT ["/usr/bin/docker-init", "/usr/bin/dockerd"]