The document discusses software packaging for cross-platform distribution by building Debian packages inside a container. It provides examples of building a simple "Hello World" package and modifying an existing "nvidia-graphics-drivers" package. It demonstrates setting up a Debian environment in a Docker container, creating packages without root privileges, and implementing packaging as infrastructure code using a Dockerfile. The document promotes open source and discusses using Podman instead of Docker for containerization.

1. Software Packaging for
Cross OS Distribution
Build Debian Package in Container for Example
Jian-Hong Pan (StarNight)
@ COSCUP 2019

2. Outline
● History
● Packaging tools
● Have a Debian in a
Container
● Hello World Example
○ Prepare
○ Build
○ Install
● Advanced Example
○ nvidia-graphics-drivers
○ Don’t use root by default
● Infrastructure as Code
○ Script by Dockerfile
○ Code, Config, Data
● Docker to Podman
● Further Usage …

3. Who am I
潘建宏 / Jian-Hong Pan (StarNight)
Work in Endless Mobile now.
You can find me at ～
http://www.slideshare.net/chienhungpan/
GitHub : starnight
Email : starnight [AT] g.ncu.edu.tw

4. History
● Used Red Hat, then Ubuntu for few years, then ...
● [TOSSUG] Debian 套件打包工作坊 / Debian packaging
workshop (1) ~ 11 in 2015
● Packaging Workshop by Shih-Yuan Lee in DebConf 2018
○ Debian Package

5. But I use Arch Linux,
not Debian based distribution
教練，我好想打 球 包 package!
I still need to build debian package

6. How to build deb on none Debian based?
● Creating packages for other distributions
○ dpkg, devscripts, debootstrap … are in AUR, except quilt
○ No isolation (user space) and messes up my computer (not clean)
● Virtual Machine
○ Debian in a VM. It works, but heavy.
● Container
○ Light weight, but frustrates me in some procedure. Try to accomplish it.

7. Use docker as the container tool
(temporarily)
$ systemctl start docker

8. Debian Releases
● stable
○ The stable distribution contains the latest officially released distribution of
Debian.
○ The current "stable" distribution of Debian is version 10, codenamed
buster.
● testing
○ The testing distribution contains packages that haven't been accepted
into a stable release yet, but they are in the queue for that.
○ The current "testing" distribution is bullseye.
● unstable
○ The unstable distribution is where active development of Debian occurs.
○ The "unstable" distribution is always called sid.
Reference: Debian Releases

9. Let’s Play with Latest Environment
● debian on docker hub
● Have the docker image
○ $ docker pull debian:sid
○ $ docker run -it --name test debian:sid bash
root@4e45f0e12843:/#
$ docker run --help
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Run a command in a new container
Options:
...
-i, --interactive Keep STDIN open even if not attached
…
--name string Assign a name to the container
...
-t, --tty Allocate a pseudo-TTY
● Have an isolated debian environment with root now

10. The APT Source List
● The apt source list:
# cat /etc/apt/sources.list
deb http://deb.debian.org/debian sid main
● Update and upgrade packages:
○ # apt update -y && apt upgrade -y
● Install some packages
○ # apt install vim -y

11. Install Debian Package Tools
● # apt install debhelper devscripts build-essential -y --no-install-recommends
● # apt search debhelper
debhelper/unstable,now 12.1.1 all [installed]
helper programs for debian/rules
● # apt search devscripts
devscripts/unstable,now 2.19.5 amd64 [installed]
scripts to make the life of a Debian Package maintainer easier
● # apt search build-essential
build-essential/unstable,now 12.6 amd64 [installed]
Informational list of build-essential packages
If you do not plan to build Debian packages, you don't need this package.
Starting with dpkg (>= 1.14.18) this package is required for building Debian
packages.

12. Start from a Simple Hello World Package
1. Have a working directory
a. # mkdir -p ~/helloworld/helloworld-0.1 && cd ~/helloworld/helloworld-0.1
2. Get source code
a. # vim helloworld
#!/bin/sh
echo "Hello world!"
echo "Now is "`date`

13. Debian Source Package
+
Original
upstream
code
debian/
…
...

14. 3. debian package configuration - debian/control
a. # mkdir debian && vim debian/control
Source: helloworld
Maintainer: Real Name <Real E-mail address>
Section: misc
Priority: extra
Standards-Version: 4.3.0
Package: helloworld
Architecture: all
Description: Simple hello world
4. Have the build script - debian/rules
a. # cp /usr/share/doc/debhelper/examples/rules.tiny debian/rules
5. Where to install the application - debian/install
a. # echo $'helloworldt/usr/bin/' > debian/install

15. 6. debhelper compatibility level - debian/compat
a. # echo 10 > debian/compat
7. Write the change log - debian/changelog
a. # dch --create --package helloworld -v 0.1 -D experimental
helloworld (0.1) experimental; urgency=medium
* Initial release.
-- Real Name <Real E-mail address> Sun, 09 Jun 2019 08:04:23 +0000
8. Build deb package
a. # dpkg-buildpackage -rfakeroot -uc -us

16. Install the Built deb Package
● Install
# cd ~ && dpkg -i ~/helloworld/helloworld_0.1_all.deb
● List the installed package
# dpkg -l | grep helloworld
ii helloworld 0.1 all Simple hello world
● Test
# helloworld
Hello world!
Now is Sun Jun 9 09:38:29 UTC 2019

17. Try to modify existed package
nvidia-graphics-drivers for example

18. nvidia-graphics-drivers Source Package
1. # mkdir ~/nvidia && cd ~/nvidia
2. # apt source nvidia-graphics-drivers
Reading package lists... Done
E: You must put some 'source' URIs in your sources.list
3. # cat /etc/apt/sources.list
# deb http://snapshot.debian.org/archive/debian/2019... sid main
deb http://deb.debian.org/debian sid main ??
nvdia-graphics-drivers in non-free component

19. Add Source Entry and Component
1. Edit source.list:
# vim /etc/apt/sources.list
deb http://deb.debian.org/debian sid main contrib non-free
deb-src http://deb.debian.org/debian sid main contrib non-free
2. Update list of available packages
# apt update

20. nvidia-graphics-drivers source package
# cd ~/nvidia && apt source nvidia-graphics-drivers
Reading package lists... Done
NOTICE: 'nvidia-graphics-drivers' packaging is maintained in the 'Git' version control system at:
https://salsa.debian.org/nvidia-team/nvidia-graphics-drivers.git
Please use:
git clone https://salsa.debian.org/nvidia-team/nvidia-graphics-drivers.git
to retrieve the latest (possibly unreleased) updates to the package.
Need to get 107 MB of source archives.
Get:1 http://deb.debian.org/debian sid/non-free nvidia-graphics-drivers 418.74-1 (dsc) [6624 B]
Get:2 http://deb.debian.org/debian sid/non-free nvidia-graphics-drivers 418.74-1 (tar) [107 MB]
Get:3 http://deb.debian.org/debian sid/non-free nvidia-graphics-drivers 418.74-1 (tar) [137 B]
Get:4 http://deb.debian.org/debian sid/non-free nvidia-graphics-drivers 418.74-1 (diff) [186 kB]
Fetched 107 MB in 32s (3322 kB/s)
dpkg-source: info: extracting nvidia-graphics-drivers in nvidia-graphics-drivers-418.74
dpkg-source: info: unpacking nvidia-graphics-drivers_418.74.orig.tar.gz
dpkg-source: info: unpacking nvidia-graphics-drivers_418.74.orig-amd64.tar.gz
dpkg-source: info: unpacking nvidia-graphics-drivers_418.74-1.debian.tar.xz
W: Download is performed unsandboxed as root as file 'nvidia-graphics-drivers_418.74-1.dsc' couldn't be
accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)

21. See helloworld Building Message Again
root@4e45f0e12843:~/helloworld/helloworld-0.1# dpkg-buildpackage -rfakeroot -uc -us
dpkg-buildpackage: warning: using a gain-root-command while being root
dpkg-buildpackage: info: source package helloworld
dpkg-buildpackage: info: source version 0.1
dpkg-buildpackage: info: source distribution experimental
dpkg-buildpackage: info: source changed by Jian-Hong Pan <starnight@g.ncu.edu.tw>
dpkg-buildpackage: info: host architecture amd64
…
“Do not” use as root by default in container!!!

22. Add a New User
1. Sudo: execute a command as another user
a. # apt install sudo
2. Add a new user, and change to it
a. # useradd -m -G sudo <user name> && passwd <user name>
b. # sudo -u <user name> sh
3. Have the helloworld again
a. $ sudo cp -r /root/helloworld ~/
b. $ cd ~
c. $ sudo chown -R <user name>:<user name> helloworld
4. Build the packages with new user again
a. $ cd helloworld/helloworld-0.1 && dpkg-buildpackage -rfakeroot -uc -us

23. Wrap up! Infrastructure as Code!
Dockerfile

24. Dockerfile
$ mkdir test-docker && cd test-docker && vim Dockerfile
FROM debian:sid
RUN cp /etc/apt/sources.list /etc/apt/sources.list.old &&
grep -vE "^#" /etc/apt/sources.list.old |
awk '{printf "%s contrib non-freen%s-src %s contrib non-freen", $0, $1, substr($0, index($0,$2))}' >
/etc/apt/sources.list &&
apt update -y && apt upgrade -y &&
apt -y --no-install-recommends install sudo vim debhelper devscripts build-essential &&
useradd -m -G sudo <user name> &&
echo <user name>":1234" | chpasswd
USER <user name>
WORKDIR /home/<user name>
CMD bash

25. Have a Container from Dockerfile
1. Build image from the Dockerfile
$ docker build -t $(id -nu)/debian . --no-cache
$ docker build --help
Usage: docker build [OPTIONS] PATH | URL | -
Build an image from a Dockerfile
Options:
...
--no-cache Do not use cache when building the image
...
-t, --tag list Name and optionally a tag in the
2. Run a container with the image as a base
$ docker run -it --name mycontainer $(id -nu)/debian bash

26. Code
Config Data
In Container
Out Container

27. Mount Host user’s HOME to Container
Before mount host user’s HOME directory:
● File’s owner and group must be the same for inside and
outside container
● Grant privileges to general user in container

28. Final Dockerfile
FROM debian:sid
ARG USER_NAME
ARG USER_ID
ARG GROUP_NAME
ARG GROUP_ID
RUN cp /etc/apt/sources.list /etc/apt/sources.list.old &&
grep -vE "^#" /etc/apt/sources.list.old |
awk '{printf "%s contrib non-freen%s-src %s contrib non-freen", $0, $1, substr($0, index($0,$2))}' >
/etc/apt/sources.list &&
apt update -y && apt upgrade -y &&
apt -y --no-install-recommends install sudo vim debhelper devscripts build-essential &&
apt clean &&
echo "set number" >> /etc/vim/vimrc &&
groupadd -g ${GROUP_ID} ${GROUP_NAME} &&
useradd -g ${GROUP_NAME} -G sudo -u ${USER_ID} ${USER_NAME} &&
echo ${USER_NAME}":1234" | chpasswd &&
rm /etc/localtime &&
ln -s /usr/share/zoneinfo/Asia/Taipei /etc/localtime
USER ${USER_NAME}
CMD bash

29. Also Pass Arguments to Dockerfile
$ docker build --build-arg USER_ID=$(id -u) --build-arg GROUP_ID=$(id -g)
--build-arg USER_NAME=$(id -nu) --build-arg GROUP_NAME=$(id -ng) -t $(id
-nu)/debian . --no-cache
$ docker build --help
Usage: docker build [OPTIONS] PATH | URL | -
Build an image from a Dockerfile
Options:
…
--build-arg list Set build-time variables

30. Run as User and Mount Host Folder
$ docker run -it -v ~:/home/$(id -nu) -w /home/$(id -nu) --user $(id -nu) --name
mycontainer $(id -nu)/debian bash
$ docker run --help
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Run a command in a new container
Options:
…
-u, --user string Username or UID (format: <name|uid>[:<group|gid>])
…
-v, --volume list Bind mount a volume
…
-w, --workdir string Working directory inside the container

31. Use Podman instead of docker
● Podman is a daemonless container engine for developing,
managing, and running OCI Containers on your Linux
System.
● Containers can either be run as root or in rootless mode.
● `alias docker=podman`
● All of the commands mentioned above, the “docker” can
be changed to “podman” directly.
● Replacing Docker With Podman by Dan Walsh (video)
● Podman 介紹 by Gene Kuo
Reference: https://podman.io/

32. CI & CD
Customized
Packaging
Environment
Packaging script
Package
Source Code
Container

33. Code 進得去，
Submit code,
Package 出得來，
Get package,
大家一起開源發大財！
Open Source enriches your life!

34. Keep True Freedom

35. Reference
● Packaging
● Introduction to Debian Packaging
● Building tutorial
● Debian Packaging Tutorial by Lucas Nussbaum
● Podman