A super small Docker image based on [Alpine Linux][alpine]. The image is only 5 MB and has access to a package repository that is much more complete than other BusyBox based images.
Docker images today are big. Usually much larger than they need to be. There are a lot of ways to make them smaller, but the Docker populace still jumps to the ubuntu base image for most projects. The size savings over ubuntu and other bases are huge:
REPOSITORY TAG IMAGE ID CREATED SIZE
containerstack/alpine latest e6efe7544e54 18 minutes ago 3.97MB
debian latest a25c1eed1c6f 3 days ago 123MB
centos latest 3bee3060bfc8 5 days ago 193MB
ubuntu latest 7b9b13f7b9c0 8 days ago 118MB
fedora latest 15895ef0b3b2 7 weeks ago 231MB
There are images such as progrium/busybox which get us very close to a minimal container and package system. But these particular BusyBox builds piggyback on the OpenWRT package index which is often lacking and not tailored towards generic everyday applications. Alpine Linux has a much more complete and up to date [package index][alpine-packages]:
Stop doing this:
FROM ubuntu-debootstrap:14.04
RUN apt-get update -q \
&& DEBIAN_FRONTEND=noninteractive apt-get install -qy mysql-client \
&& apt-get clean \
&& rm -rf /var/lib/apt
ENTRYPOINT ["mysql"]This took 19 seconds to build and yields a 164 MB image. Eww. Start doing this:
FROM containerstack/alpine:3.7.0
RUN apk add --no-cache mysql-client
ENTRYPOINT ["mysql"]Only 3 seconds to build and results in a 36 MB image! Hooray!
Links to usefull websites
[Alpine]: http://alpinelinux.org/
[Alpine Packages]: http://pkgs.alpinelinux.org/
[About Alpine]: https://www.alpinelinux.org/about/
[GitHub Issues]: https://github.com/containerstack/docker-alpine/issues
[Docker Hub]: https://hub.docker.com/r/containerstack/alpine-arm/