Developer documentation summary

This section explains various topics helpful to participate with the software development of WALT.

Collaborative workflow

If you want to participate in the development of walt, email us: walt-contact at

We welcome any contribution, bugfix, new feature, documentation update, more automated tests, etc. If you implement something, you can use the “pull request” feature of github. WalT is based on various github repositories. Scroll down for the list.

Experimental setup

Each developer must install a dedicated WALT platform for allowing development and testing without disturbing experimental work or other developers. This involves:

  1. Install walt server software on a dedicated machine.

  2. Optionally, connect one or more network switches, and physical nodes (or just use virtual nodes).

Note about step 1: since the purpose of this platform is just software development, a small-form-factor PC is largely enough. But remember that walt server software starts various network daemons, so the machine should be dedicated for this purpose only. Don’t try to install walt server software on your laptop!

With this setup in place, the developer can connect as root to the development server, and modify the code, restart the main server daemon, test walt client tool, etc.

For installing the server, you can mostly follow walt help show server-install. However, for a more developer-friendly setup, commands at step 2 should be replaced.

If you are a core developer (with push access to the repository) just run the following instead:

root@walt-server$ git clone
root@walt-server$ make -j install

If you are not a core developer, you can instead fork our repository by pointing your browser to the following URL, and validate: Then, run the two commands above, but clone you own repository instead (i.e., replace drakkar-lig by your own username on github).

When you want to reinstall the code you modified, run make -j install again.


The WalT project relies on various code repositories:

  • the main repository of WalT platform code. It includes server code, client code, common code, optional code to be installed on WalT OS images, etc. The various walt-* pip packages published on PyPI are built from this repository. For helping developers understand the code structure and various important topics, this repository has its own documentation pages. See walt help show dev-walt-python-packages.

  • a repository building various WalT OS images to be booted by WalT nodes, including the default image of each WalT node model we support.

  • a repository for building network bootloaders useful to turn a computer into a WalT node. Some node models, such as recent Raspberry Pi board and some x86 computers do not need such a specific bootloader because their firmware is already capable of network booting. This repository remains useful for turning other kinds of computers or SBCs into WalT nodes.

  • the repository where we announce new WalT versions. With each version we link some build artefacts of the other repositories. There is no source code there. Since WalT relies on several code repositories, it is probably easier for the end user to find all these artefacts at a single place.

  • the repository for building and uploading the pip package It allows to interact with debian package manager apt, when running walt-server-setup to install or upgrade a WalT server. The underlying code is developed by Debian developers and available as a Debian package called python3-apt, but it was not available on PyPI, thus not installable in a python virtual environment.

  • the repository allowing to turn a raspberry pi 3B/3B+ board into a WalT VPN node. It generates an SD card image file. See walt help show vpn for more info.