Deploy linux applications

TODO: virtual box for unbuntu 18.04 -> add user to vboxsf group to access shared folders sudo adduser $USER vboxsf -> install C++ ccompiler sudo apt install g++ -> install xcb platform needed by qt: sudo apt install libxcb-xinerama0 -> install libgl-dev needed by qt: sudo apt install libgl-dev -> install Qt (5.9.9)

At RxLaboratory, we deploy linux applications in two formats: Deb packages for Debian/Ubuntu, and AppImage files for other distributions.

Let’s assume the application has already been built and consists in at least one executable binary. This is the procedure to follow to deploy the application.


To ensure a vast compatibility, apps have to be built and deployed at least on Ubuntu 18.04 Bionic Beaver and not on any other more recent version.


If the desktop file has issues, the Deb and AppImage won’t be built, and for the Deb, dpkg will not warn about the issue. It may be easier to start with the AppImage to make sure the desktop file works, or have some info about what may be wrong.

Install a virtual machine to build and test on older distros

If this machine is used for building applications

Deb packages

When updating an existing package, you can just update the changelog and jump to the 4th section.

1. Create the file and folder structure


|- usr
  |- bin
   |- share
      |- applications
      |- doc
         |- AppName
      |- icons
         |- hicolor
            |- 24x24
               |- apps
            |- 32x32
               |- apps
            |- 48x48
               |- apps
            |- 128x128
               |- apps
            |- 256x256
               |- apps

An empty folder structure is available in RAINBOX/ADMIN/DEV/00 - Docs/LINUX/Build Deb Package/Example-Package-Folder

2. Edit the usr/share/applications/*.desktop file.


[Desktop Entry]
GenericName=Media Encoder
Comment=The Duduf Media Encoder, a fast, easy-to-use, versatile media encoder.

The list of Main Categories is available here, which can be completed by the list of Additional Categories.

The mime type is optional. A list of mime types is available here.

3. Edit the usr/share/doc/AppName/copyright file


Upstream-Name: DuME The Duduf Media Encoder

Files: *
Copyright: 2017-2020 Nicolas Dufresne
License: GPL-3+
 This program is free software; you can redistribute them and/or modify them under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY
 On Debian systems, the full text of the GNU General Public License version 2 can be found in the file `/usr/share/common-licenses/GPL-2'.

4. Edit the DEBIAN/control file.


Package: DuME
Version: 0.1.2
Architecture: amd64
Essential: no
Section: video
Priority: optional
Depends: ffmpeg (>=4.0), qt5-default
Maintainer: Duduf
Installed-Size: 6900
Description: A fast, easy-to-use and versatile media encoder.

The section can be one of: admin, cli-mono, comm, database, debug, devel, doc, editors, education, electronics, embedded, fonts, games, gnome, gnu-r, gnustep, graphics, hamradio, haskell, httpd, interpreters, introspection, java, javascript, kde, kernel, libdevel, libs, lisp, localization, mail, math, metapackages, misc, net, news, ocaml, oldlibs, otherosfs, perl, php, python, ruby, rust, science, shells, sound, tasks, tex, text, utils, vcs, video, web, x11, xfce, zope.
The additional section debian-installer contains special packages used by the installer and is not used for normal Debian packages.

Installed-Size should be the size of the usr folder in the package, in kB. The disk space is given as the integer value of the estimated installed size in bytes, divided by 1024 and rounded up.

See this page on for more details.

5. Generate md5sums

Run this command from the root of the package folder:

find . -type f ! -regex '.*.hg.*' ! -regex '.*?debian-binary.*' ! -regex '.*?DEBIAN.*' -printf '%P ' | xargs md5sum > DEBIAN/md5sums

6. Build deb package

Run this command:

chmod 755 folder/DEBIAN
dpkg -b folder app-0.0.0-amd64.deb


The chmod command won’t work on NTFS file systems. Therefore, the Deb package can only be built on a linux file system.

Here is a bash script to automate the last two steps:


# usage: ./deploy-deb AppName
# The deb folder must be named "AppName-Deb" and located next to the script

# generate md5sums
cd "$1-Deb"
find . -type f ! -regex '.*.hg.*' ! -regex '.*?debian-binary.*' ! -regex '.*?DEBIAN.*' -printf '%P ' | xargs md5sum > DEBIAN/md5sums

# chmod 
chmod 755 DEBIAN
# build
cd ..
dpkg -b "$1-Deb" "$1.deb"


1. Create the file and folder structure

This is the same as for Deb packages, except the DEBIAN control folder is not needed.

2. Build using the linuxdeployqt utility

Run this command using a linuxdeployqt appImage. Replace desktopFile with the path to the desktop file inside the Deb package.

./linuxdeployqt-6-x86_64.AppImage desktopFile -unsupported-allow-new-glibc -always-overwrite -appimage -no-translations -qmake=/home/duduf/Qt/5.9.9/gcc_64/bin/qmake -extra-plugins=iconengines,platformthemes/


Make sure the application has been built with a version of Qt with an available qmake bin, and it’s the correct one in the command above.