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.
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:
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:3.6.2 RUN apk add --no-cache mysql-client ENTRYPOINT ["mysql"]
Only 3 seconds to build and results in a 36 MB image! Hooray!