Alpine Linux Docker Image

Welcome to the documentation for the Alpine Linux Docker Image. Here we explain a bit about the motivations behind this image, how you typically use it, the build process, and how to make great minimalist containers!

About

The heart of this image is Alpine Linux. The image is only 5 MB and has access to a package repository that is much more complete than other minimal base images. Learn more about this image, musl libc, BusyBox, and why the Docker Alpine Linux image makes a great base for your Docker projects.

Official

This image serves as the source for the official Alpine Linux image in the Docker Library. The build process for both official alpine and gliderlabs/alpine are the same. However, different build options are used for the official library images. Check out the build page for more information on differences.

Motivations

Docker images today are big. Usually much larger than they need to be. There are a lot of ways to make them smaller. But you need to start with a small base. There are great size savings to be had when compared to base images such as ubuntu, centos, and debian.

Usage

You use the apk command to manage packages. We don't ship the image with a package index (since that can go stale fairly quickly), so you need to add the --update-cache flag to apk when installing. An example installing the nginx package would be apk add --update-cache nginx. Check out the usage page for more advanced usage and Dockerfile examples.

Caveats

The musl libc implementation may work a little different than you are used to. One example of this is with DNS. musl libc does not use domain or search in the /etc/resolv.conf file. It also queries name servers in parallel which can be problematic if your first name server has a different DNS view (such as service discovery through DNS). We have a page dedicated to the caveats you should be aware of.

Build

This image is built and tested in a continuous integration environment using the build script. We then push the resulting images directly to Docker Hub. Check out the page on building and testing the images for more information.

Contacts

We make reasonable efforts to support our work and are always happy to chat. Join us in our Slack community or submit a GitHub issue if you have a security or other general question about this Docker image. Please email security or user mailing lists if you have concerns specific to Alpine Linux.

Contributing

We welcome contributions to the image build process, version bumps, and other optimizations. The image gets built and pushed from the release branch automatically. Once a pull request is merged, a build will be kicked off, and resulting image pushed to Docker Hub in a matter of minutes!

docker-alpine :: index