Create a base image

ゝ一纸荒年。 2022-09-21 13:27 12阅读 0赞

# Create a base image #

So you want to create your own [ *Base Image*][_Base Image]? Great!

The specific process will depend heavily on the Linux distribution you want to package. We have some examples below, and you are encouraged to submit 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 running the distribution you’d like to package as a base image, though that is not required for some tools like Debian’s [Debootstrap][], which you can also use 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 - raring
    a29c15f1bf7a
    $ docker run raring cat /etc/lsb-release
    DISTRIB_ID=Ubuntu
    DISTRIB_RELEASE=13.04
    DISTRIB_CODENAME=raring
    DISTRIB_DESCRIPTION="Ubuntu 13.04"

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

*  [BusyBox][]
 *  CentOS / Scientific Linux CERN (SLC) [ on Debian/Ubuntu][on Debian_Ubuntu] or [ on CentOS/RHEL/SLC/etc.][on CentOS_RHEL_SLC_etc.]
 *  [Debian / Ubuntu][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 the `scratch` “image” signals to the build process that you want the next command in the `Dockerfile` 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 name `scratch`. Instead, you can refer to it in your `Dockerfile`. For example, to create a minimal container using `scratch`:

FROM scratch
    ADD hello / CMD ["/hello"]

This example creates the hello-world image used in the tutorials. If you want to test it out, you can clone [the 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][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 also written a [ `Dockerfile` Best Practices guide][_Dockerfile_ Best Practices guide].
 *  If your goal is to create a new Official Repository, be sure to read up on Docker’s [Official Repositories][].

[_Base Image]: https://docs.docker.com/engine/reference/glossary/#base-image
[Debootstrap]: https://wiki.debian.org/Debootstrap
[BusyBox]: https://github.com/docker/docker/blob/master/contrib/mkimage-busybox.sh
[on Debian_Ubuntu]: https://github.com/docker/docker/blob/master/contrib/mkimage-rinse.sh
[on CentOS_RHEL_SLC_etc.]: https://github.com/docker/docker/blob/master/contrib/mkimage-yum.sh
[Debian _ Ubuntu]: https://github.com/docker/docker/blob/master/contrib/mkimage-debootstrap.sh
[the image repo]: https://github.com/docker-library/hello-world
[complete guide to all the instructions]: https://docs.docker.com/engine/reference/builder/
[_Dockerfile_ Best Practices guide]: https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/
[Official Repositories]: https://docs.docker.com/docker-hub/official_repos/