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 VIRTUAL SIZE wesleycharlesblake/alpine-linux latest 157314031a17 5.03 MB debian latest 4d6ce913b130 84.98 MB ubuntu latest b39b81afc8ca 188.3 MB centos latest 8efe422e6104 210 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][alpine-packages]:
$ docker run progrium/busybox opkg-install nodejs Unknown package 'nodejs'. Collected errors: * opkg_install_cmd: Cannot install package nodejs. $ docker run wesleycharlesblake/alpine-linux apk add --no-cache nodejs fetch http://alpine.gliderlabs.com/alpine/v3.3/main/x86_64/APKINDEX.tar.gz fetch http://alpine.gliderlabs.com/alpine/v3.3/community/x86_64/APKINDEX.tar.gz (1/4) Installing libgcc (5.3.0-r0) (2/4) Installing libstdc++ (5.3.0-r0) (3/4) Installing libuv (1.7.5-r0) (4/4) Installing nodejs (4.2.3-r0) Executing busybox-1.24.1-r7.trigger OK: 29 MiB in 15 packages
This makes Alpine Linux a great image base for utilities and even production applications. [Read more about Alpine Linux here][alpine-about] and you can see how their mantra fits in right at home with Docker images.
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 wesleycharlesblake/alpine-linux:3.3 RUN apk add --no-cache mysql-client ENTRYPOINT ["mysql"]
Only 3 seconds to build and results in a 36 MB image! Hooray!
This image is well documented. [Check out the documentation at Viewdocs][docs] and the
docs directory in this repository.