BuildDebianDockerImageLocally
Aug 29, 2017
Technology
AIM
Recently I am working in a network isolated environment, this means, I am unable to connect to internet freely. But I have to finish my working using some specific docker images, how? So I have to build them locally using iso.
Preparation
Download debian dvds from internet and tranfer them into the intranet:
# ls -l debian*
-rw-r--r-- 1 dash root 3.6G Jul 21 00:59 debian-9.0.0-amd64-DVD-1.iso
-rw-r--r-- 1 dash root 4.4G Jul 21 01:57 debian-9.0.0-amd64-DVD-2.iso
-rw-r--r-- 1 dash root 4.4G Jul 21 02:52 debian-9.0.0-amd64-DVD-3.iso
Install debian in virtualbox using debian-9.0.0-amd64 DVD1 iso. Using basic desktop with sshd server.
Repository
Change the repository with following command:
# mount -t iso9660 -o loop /media/sdb/iso/debian-9.0.0-amd64-DVD-1.iso /media/sdb/debianrepo/cd1/
# mount -t iso9660 -o loop /media/sdb/iso/debian-9.0.0-amd64-DVD-2.iso /media/sdb/debianrepo/cd2/
# mount -t iso9660 -o loop /media/sdb/iso/debian-9.0.0-amd64-DVD-3.iso /media/sdb/debianrepo/cd3/
While the directory /media/sdb/debianrepo/ is the directory under the web server. Thus we could change the apt’s source file pointint to this webserver.
# vim /etc/apt/sources.list
deb http://192.168.56.1/debianrepo/cd1/ stable main contrib
deb http://192.168.56.1/debianrepo/cd2/ stable main contrib
deb http://192.168.56.1/debianrepo/cd3/ stable main contrib
Enable the Unauthenticated installation, and install vim for testing:
# vim /etc/apt/apt.conf.d/99myown
APT::Get::AllowUnauthenticated "true";
# apt-get update
# apt-get -y install vim
BootStrap
Standard Bootstrap won’t be used, so we have to use a tool called demoostrap.
Download position:
# git clone https://github.com/jwilk/demoostrap.git
Install some necessray packages:
# apt-get install -y python3-debian apt-utils debootstrap dpkg-repack
demoostrap the basic filesystem via:
# mkdir docker_root
# ./demoostrap docker_root/
# du -hs docker_root/
179M docker_root/
In next step we will chroot into this new filesystem and install some necessary package.
chroot
The filesystem under docker_root only contains basic filesystem. In order to work properly we have to install at least minimum apt-get, so following are the steps:
# mount -t devpts devpts docker_root/dev/pts
# mount -t proc proc docker_root/proc
# mount -t sysfs sysfs docker_root/sys
Before chroot into the system we have to download some packages manually into the docker_root folder, because in chrooted system we could only use dpkg for installation.
# mkdir -p docker_root/install
# cd docker_root/install
# wget http://192.192.192.91/debianrepo/cd1/debian/debian/pool/main/a/apt/apt_1.4.6_amd64.deb
# wget http://192.192.192.91/debianrepo/cd1/debian/pool/main/a/apt/libapt-pkg5.0_1.4.6_amd64.deb
# wget http://192.192.192.91/debianrepo/cd1/debian//pool/main/g/gcc-6/libstdc++6_6.3.0-18_amd64.deb
# wget http://192.192.192.91/debianrepo/cd1/debian/pool/main/a/adduser/adduser_3.115_all.deb
# wget http://192.192.192.91/debianrepo/cd1/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2017.5_all.deb
# wget http://192.192.192.91/debianrepo/cd1/debian//pool/main/g/gnupg2/gpgv_2.1.18-6_amd64.deb
Now chroot in, and manually install these packages:
# chroot docker_root/
# cd /install
# dpkg -i gpgv_2.1.18-6_amd64.deb
# dpkg -i libstdc++6_6.3.0-18_amd64.deb
# dpkg -i libapt-pkg5.0_1.4.6_amd64.deb
# dpkg -i debian-archive-keyring_2017.5_all.deb
# dpkg -i adduser_3.115_all.deb
# dpkg -i apt_1.4.6_amd64.deb
# which apt-get
/usr/bin/apt-get
Further Modification
In host machine, we manually change the sources.list file and
Now we could exit the chroot system, and tar docker_root directory,
# vim etc/apt/sources.list
deb http://192.168.56.1/debianrepo/cd1/ stable main contrib
deb http://192.168.56.1/debianrepo/cd2/ stable main contrib
deb http://192.168.56.1/debianrepo/cd3/ stable main contrib
Enable the Unauthenticated installation:
# vim etc/apt/apt.conf.d/99myown
APT::Get::AllowUnauthenticated "true";
zip and import
tar the directory using following command:
# tar czvf docker_root.tar.gz docker_root/
Then in the untared directory you could import it into docker repository via:
# tar -c * | docker import - myowndebian:raw
# docker images | grep myowndebian
myowndebian raw 909759ad7fad 23 seconds ago 189MB
# docker run -it myowndebian:raw /bin/bash
root@f95e7f8d6427:/# ls
bin dev home lib media opt root sbin sys usr
boot etc install lib64 mnt proc run srv tmp var
At this point, you have a selt-built docker box, from this start point you could add more packages into your docker images and form your own images offline. Just enjoy it!