A super small Docker image based on Alpine Linux. The image is only 5 MB and has access to a package repository that is much more complete than other BusyBox based images.

Why?

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          VIRTUAL SIZE
gliderlabs/alpine   latest        9cfff538e583      4.803 MB
debian              latest        19134a8202e7      123.1 MB
ubuntu              latest        104bec311bcd      129 MB
centos              latest        67591570dd29      191.8 MB

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: