71 lines
3.0 KiB
Markdown
71 lines
3.0 KiB
Markdown
<!--[metadata]>
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+++
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title = "Create a base image"
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description = "How to create base images"
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keywords = ["Examples, Usage, base image, docker, documentation, examples"]
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[menu.main]
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parent = "smn_images"
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+++
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<![end-metadata]-->
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# Create a base image
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So you want to create your own [*Base Image*](../reference/glossary.md#base-image)? Great!
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The specific process will depend heavily on the Linux distribution you
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want to package. We have some examples below, and you are encouraged to
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submit pull requests to contribute new ones.
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## Create a full image using tar
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In general, you'll want to start with a working machine that is running
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the distribution you'd like to package as a base image, though that is
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not required for some tools like Debian's
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[Debootstrap](https://wiki.debian.org/Debootstrap), which you can also
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use to build Ubuntu images.
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It can be as simple as this to create an Ubuntu base image:
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$ sudo debootstrap raring raring > /dev/null
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$ sudo tar -C raring -c . | docker import - raring
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a29c15f1bf7a
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$ docker run raring cat /etc/lsb-release
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DISTRIB_ID=Ubuntu
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DISTRIB_RELEASE=13.04
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DISTRIB_CODENAME=raring
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DISTRIB_DESCRIPTION="Ubuntu 13.04"
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There are more example scripts for creating base images in the Docker
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GitHub Repo:
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- [BusyBox](https://github.com/docker/docker/blob/master/contrib/mkimage-busybox.sh)
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- CentOS / Scientific Linux CERN (SLC) [on Debian/Ubuntu](
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https://github.com/docker/docker/blob/master/contrib/mkimage-rinse.sh) or
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[on CentOS/RHEL/SLC/etc.](
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https://github.com/docker/docker/blob/master/contrib/mkimage-yum.sh)
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- [Debian / Ubuntu](
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https://github.com/docker/docker/blob/master/contrib/mkimage-debootstrap.sh)
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## Creating a simple base image using scratch
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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.
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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`:
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FROM scratch
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ADD hello /
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CMD ["/hello"]
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This example creates the hello-world image used in the tutorials.
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If you want to test it out, you can clone [the image repo](https://github.com/docker-library/hello-world)
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## More resources
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There are lots more resources available to help you write your 'Dockerfile`.
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* There's a [complete guide to all the instructions](../reference/builder.md) available for use in a `Dockerfile` in the reference section.
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* To help you write a clear, readable, maintainable `Dockerfile`, we've also
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written a [`Dockerfile` Best Practices guide](dockerfile_best-practices.md).
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* If your goal is to create a new Official Repository, be sure to read up on Docker's [Official Repositories](https://docs.docker.com/docker-hub/official_repos/).
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