Create a base image

So you want to create your own Base Image? Great!

The specific process will depend heavily on the Linux distribution youwant to package. We have some examples below, and you are encouraged tosubmit pull requests to contribute new ones.

Create a full image using tar

In general, you’ll want to start with a working machine that is runningthe distribution you’d like to package as a base image, though that isnot required for some tools like Debian’sDebootstrap, which you can alsouse to build Ubuntu images.

It can be as simple as this to create an Ubuntu base image:

$ sudo debootstrap raring raring > /dev/null$ sudo tar -C raring -c . | docker import - raringa29c15f1bf7a$ docker run raring cat /etc/lsb-releaseDISTRIB_ID=UbuntuDISTRIB_RELEASE=13.04DISTRIB_CODENAME=raringDISTRIB_DESCRIPTION="Ubuntu 13.04"

There are more example scripts for creating base images in the DockerGitHub Repo:

• BusyBox
• CentOS / Scientific Linux CERN (SLC) on Debian/Ubuntu oron CentOS/RHEL/SLC/etc.
• Debian / Ubuntu

Creating a simple base image using scratch

You can use Docker’s reserved, minimal image, scratch, as a starting point for building containers. Using thescratch “image” signals to the build process that you want the next command in theDockerfile to be the first filesystem layer in your image.

While scratch appears in Docker’s repository on the hub, you can’t pull it, run it, or tag any image with the namescratch. Instead, you can refer to it in your Dockerfile. For example, to create a minimal container usingscratch:

FROM scratchADD hello /CMD ["/hello"]

This example creates the hello-world image used in the tutorials.If you want to test it out, you can clonethe image repo

More resources

There are lots more resources available to help you write your ‘Dockerfile`.

• There’s a complete guide to all the instructions available for use in a Dockerfile in the reference section.
• To help you write a clear, readable, maintainable Dockerfile, we’ve alsowritten aDockerfile Best Practices guide.
• If your goal is to create a new Official Repository, be sure to read up on Docker’sOfficial Repositories.