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 populous 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 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 update to date package index:
$ docker run progrium/busybox opkg-install nodejs
Unknown package 'nodejs'.
Collected errors:
* opkg_install_cmd: Cannot install package nodejs.
$ docker run gliderlabs/alpine apk --update add nodejs
fetch http://dl-4.alpinelinux.org/alpine/v3.1/main/x86_64/APKINDEX.tar.gz
(1/5) Installing c-ares (1.10.0-r1)
(2/5) Installing libgcc (4.8.3-r0)
(3/5) Installing libstdc++ (4.8.3-r0)
(4/5) Installing libuv (0.10.29-r0)
(5/5) Installing nodejs (0.10.33-r0)
Executing busybox-1.22.1-r14.trigger
OK: 21 MiB in 20 packagesThis makes Alpine Linux a great image base for utilities and even production applications. Read more about Alpine Linux here 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 gliderlabs/alpine:3.1
RUN apk --update add mysql-client
ENTRYPOINT ["mysql"]
Only 3 seconds to build and results in a 16 MB image! Hooray!
This image is well documented. Check out the documentation at Viewdocs and the docs directory in this repository.
We make reasonable efforts to support our work and are always happy to chat. Feel free to join us in #gliderlabs on Freenode or submit an issue to this GitHub repository.
The motivation for this project and modifications to mkimage.sh are highly inspired by Eivind Uggedal (uggedal) and Luis Lavena (luislavena). They have made great strides in getting Alpine Linux running as a Docker container. Check out their mini-container/base image as well.
The code in this repository, unless otherwise noted, is BSD licensed. See the LICENSE file in this repository.
