This repo aims to build ROS (1) from scratch.
You will need to install Bazel, see here. Besides Bazel, you will need a C++ compiler and a Python 3 interpreter.
And no, you don't have to install any ROS packages via apt.
The code is developed and tested on Ubuntu 22.04 with Python 3.10.
So far a subset of ros-base packages can be built, including support for
- messages,
- services,
- actions, and
- dynamic reconfiguration.
Please take a look at the examples folder to get started.
Within this project I want to learn and practice Bazel as well as to learn more about how difficult and/or feasible is to use ROS with Bazel. I started the work for desktop (amd64 architecture) but the real goal is to have cross-compilation for e.g. arm64 architecture working out of the box. Moreover, the number of deps that need to be installed on the target machine should be minimal, e.g. only C++ and Python runtimes.
For C++ this means that the build system needs to cross-compile all ROS and application deps, and for Python packages this means that all of them should be native -- i.e. without compiled extensions. For this project, I tried to find alternatives with Python-only code where possible, otherwise I removed pieces of code that depend on such deps. The end effect is that the core&base ROS packages used in this repo use only native Python deps. In other words, Python deps are handled by Bazel and you don't have to install (almost) any Python packages on the target platform.
It turned out that handling C++ dependencies is not that difficult. Some of the
packages, mainly from ros_comm repo, have been fixed along the way. I believe
that those changes can be eventually merged into the main ros_comm repo and
that is why those changes are at the moment in a fork.
On the Python side, situation was more difficult. I had to refactor roslaunch
code to filter out unwanted deps (mainly the ones that require compiled Python
extensions in roslaunch). Next, roslib has complex dependencies
and I kept only strictly necessary parts. Changes to rosservice are minimal.
(Heavily) modified Python ROS packages are stored in //third_party and you can
inspect git history to get more info about the changes I made.
Regarding development for embedded platforms, I believe roscpp should be just
fine. rospy has some deps that have compiled extensions, so, rospy should
not be used for platforms other than amd64 at the moment.
Since plugin functionality depends heavily on roslib and rospack,
which I don't intend to touch any more, I won't work on ROS plugin support.
Going to a bit more detail: rospack calls Python from C++ which tremendously
complicates development for embedded platforms.