Home / server / Questions / 737671
Accepted
IAmJulianAcosta
Asked: 2015-11-20 15:14:16 +0800 CST

Can docker use host filesystem instead of an image?

  • 772

Reading this question, I understood that containers use a base image (like ubuntu) for root filesystem. Now my question is if is necessary to download a base image, if I have exactly the same OS (like ubuntu 14.04).

Is that base image redundant?

docker

1 Answers

  1. Best Answer

    No you can't. It is necessary to download or create a base image to create a docker container.

    From the docker documentation:

    Containers

    Containers include the application and all of its dependencies, but share the kernel with other containers. They run as an isolated process in userspace on the host operating system. They’re also not tied to any specific infrastructure – Docker containers run on any computer, on any infrastructure and in any cloud.

    To make a docker container independent from any specific infrastructure it is necessary to provide a base image.

    But it is quite easy to create a base image on your own. Have a look in the docker documentation for instructions.

    If your are looking for Operating-system-level virtualization with only partial filesystem isolation you should check if chroot matches your requirements.

    You should also have in mind that docker

    Images are constructed from layered filesystems so they can share common files, making disk usage and image downloads much more efficient. docker documentation

    So the overhead is not too high as the images are layered.

    • 2