Docker, start image from scratch

Question

All getting-started guides for Docker based their docker images on someone else's. However, even the base image has 180MB of virtual storage there. So,

I'm wondering, is it possible to start my docker image completely from scratch without any parent images? (If so, I'm planning to create my own base image via a net-install).

PS check here for more about Docker

Thanks

Answer 1

Find it,

How to build base boxes for Docker

Recap the steps that I had always been doing,

First make sure the debootstrap is installed:

 sudo apt-get install debootstrap

Then get the latest mkimage-debootstrap.sh:

sudo sh -xc 'curl https://raw.githubusercontent.com/dotcloud/docker/master/contrib/mkimage-debootstrap.sh > /usr/sbin/mkimage-debootstrap.sh' sudo chmod 755 /usr/sbin/mkimage-debootstrap.sh

The build step is very simple:

mkimage-debootstrap.sh sfxpt/debian sid

for Debian, and

mkimage-debootstrap.sh sfxpt/ubuntu saucy

for building an Ubuntu docker image.

Checkout the above url for all the missing details. And also,

How can I make my own base image for Docker

Answer 2

Docker Hub would be a good place to look. Gentoo is a typical preference as well as GitHub, however the registry on Docker Hub often has the links to dockerfile/s used to create the DOCker container.

As well one can Nest Docker Containers into one another. You can also use Docker Compose, pull a reference image push to yourname/mycustom-container-squash

Dockerfile 
FROM myname/my-custom-container 
ADD Build-all-my-crap.sh
RUN Build-all-my-crap.sh

As well as with VirtualBox, you can use BusyBox unpacked binaries, i.e. de-crufting Debian files for pure tar.gz i.e. bin >tar.gz , etc. and using bb-tar.gz and from scratch to unpack tarballs for a minimal base.

In my case I was tinkering with Gentoo to Pentoo, however the iso >out to get to the squashfiles, though I can add the overlay, the docker-hub server will kill the build if it takes too long. I figured just overwriting the Gentoo install with Pentoo (customized Gentoo) or next try to add overlay rsync/crsync binpackage then just emerge pkg list, clean out bins, but again this will likely time out.

Jenkler Docker Base Gentoo package on GitHub

I used the Gentoo official repo, however their shell tool tends to fail at dockerhub autobuilds for x86-hardened. (bummer)

Jenkler's method allows for a minimal yet tweaked base image. I can slide a few debian>tar into the fray temporarily, and or just build them in. GitHub allows for a bit of LFS, so I could just chop up my dir>tarballs like the example above. As I've tried to slice off the iso and squashfile, and it's not working as well as I would care for.

necrose99/my-cx-gentoo base from, use a few tools to unpack the squashfs. i.e. for some security research, being able to docker cluster or set up Pentoo in a Docker as a chroot like... (can run x11, etc.) for doing builds that might not do so healthy things to my REAL install (ALPHA packages I'm not the greatest Ebuild writer plus newer security tools).

however my new container call in my-base
emerge my new stuff
next new container call in old/old/some else from build tabs. on Docker Hub.
Not to drone on and get the moderators all mad...

Anyhow you can stack Docker images like cake layers to make a wedding cake would be a good analogy and/or kick an app into a container and build it from a base container. my-debian-ngix-www-hugo-docker from debian/public... , etc. can if Debian is your base of choice.