Helper functions to configure ROS 2 in terminals

The script ros_management.bash is a set of tools to simplify the command line when tweaking ROS 2 (compiling, networking, discovery, etc.).

It also avoids mixing ROS 1 and ROS 2 workspaces, for people using both.

Compared to classical tutorials, this tool takes care of sourcing the ROS workspaces, as long as they are listed (in overlay order) in the two variables ros1_workspaces and ros2_workspaces. A classical .bashrc is similar to:

# your future .bashrc
ros1_workspaces="/opt/ros/noetic ~/a_first_ros1_workspace ~/main_ros1_overlay"
ros2_workspaces="/opt/ros/foxy ~/some_ros2_workspace ~/main_ros2_overlay"
source /path/to/ros_management.bash

Note that ros1_workspaces does not have to be defined at all if you only use ROS 2. Most of the tools in this script are actually for ROS 2.

Installing

The script can simply be sourced from your .bashrc. In order to install it in another folder and update your .bashrc (or even the one in /etc/skel) you may use the install script.

Run install.bash -h to have an overview of the installation options :

• -d/--dest: where to copy the folder (default current location)
• -o/--opt: options to source the tool (default -p -k -lo, see below for the details)
• -s/--skel: if the /etc/skel/.bashrc should be updated as well (default False)
• -y/--yes: do not ask confirmation

If skel is used or if the destination is outside the current user home, it will require sudo privilege.

Switch between ROS 1 or ROS 2

After sourcing the script, calling ros1ws or ros2ws will source the corresponding workspaces in this terminal:

ros2_workspaces="/opt/ros/foxy ~/some_ros2_workspace ~/main_ros2_overlay"

# sourcing ros_management.bash and calling ros2ws is equivalent to:
source /opt/ros/foxy/setup.bash
source ~/some_ros2_workspace/install/setup.bash
source ~/main_ros2_overlay/install/setup.bash
# except it also cleans ROS 1 paths (from ros1_workspaces)

Sourcing arguments

Modify the prompt with -p

If sourced with -p, the script will update the bash prompt in order to know:

• whether ROS 1 is active in this terminal (this avoids messing up)
• whether ROS 2 is restricted to a specific network interface

source /path/to/ros_management.bash -p # default ROS 2 sourcing, prompt is not modified
ros1ws # ros1 is now active and [ROS1] is displayed

Restrict ROS 2 to localhost with -lo

In this case the script will set ROS_LOCALHOST_ONLY (or equivalent for Iron+) for ROS 2

Store settings with -k

If the settings are stored then any new terminal will have the same settings as the previous one, assuming that ros_management.bash is sourced in your .bashrc file.

The idea is that when working on a given robot, or a given ROS version, the special setting is only done once even if new terminals are open afterwards (it may happen when using ROS).

Manual calls to rosXws or ros_restrict will override -lo arguments in new terminals.

Settings are stored in ~/.ros_management_auto_init, delete this file to restore the default behavior

source /path/to/ros_management.bash -k && ros2ws # default to ROS 2 + store settings
ros1ws # ros1 is now active and will be active in new terminals

source /path/to/ros_management.bash -k -p # also activate prompt
ros1ws # ros1 is now active and will be active in new terminals, [ROS1] is displayed as well

ROS 2 functions

Besides the sourcing of ROS 1 / ROS 2 workspace, the main use of the tool is to help configuring ROS 2 in details.

colcon shortcuts (colbuild)

In ROS 1, catkin build could be run from anywhere inside the workspace while in ROS 2, colcon build has to be called from the root (where directories src, build and install lie). In practice, calling colcon build from e.g. your package directory will actually use this folder as the workspace.

The command colbuild offers the following behavior:

• calls colcon build --symlink-install --continue-on-errors
• can be run from anywhere inside the workspace
• before compiling: cleans the environment variables and sources the workspaces up to the current one
• after compiling: re-sources the workspaces (this is what you would do anyway)

It provides additional keywords:

• -p: similar to --packages-select
• -pu: similar to --packages-up-to
• -t, --this: compiles only the package that includes the current directory
• -tu, --this-up-to: compiles only up to the package that includes the current directory

Network: restrict to a network interface

The function ros_restrict takes a network interface (or lo / WIFI / ETH) and will only use this interface for ROS 2 (in this terminal). It will configure FastRTPS and Cyclone DDS. In practice, a few XML is needed to properly handle these cases:

• https://fast-dds.docs.eprosima.com/en/latest/fastdds/transport/whitelist.html
• https://answers.ros.org/question/365051/using-ros2-offline-ros_localhost_only1
• https://answers.ros.org/question/405753/limit-ros-traffic-to-specific-network-interface

ros_restrict WIFI  # only uses WiFi, let the script find the interface name
# or ros_restrict wlan0 if it is the name of the wifi interface

If ros_management.bash was sourced with -k then this restriction is forwarded to any new terminal.

You can get back to localhost only with ros_reset. It will set ROS_LOCALHOST_ONLY (or ROS_AUTOMATIC_DISCOVERY_RANGE for Iron+) with prefered interface being lo for ROS 2

Network: setup super client for FastDDS discovery

It is usually a good idea to use a discovery server when using ROS 2 over Wifi. The main issue is that by default, command-line tools are not able to introspect the ROS graph as nodes and topics are not automatically discovered.

Calling ros_super_client enables a super client session based on the value of ROS_DISCOVERY_SERVER, when graph introspection is required.

Network: restart daemon

Calling ros2restart will restart the ROS 2 daemon in case discovery is not functional. It will also reset any super client.

ROS 1 functions

Network: use a distant ROSMASTER on a given interface

The function ros_master will configure ROS_IP / ROS_MASTER_URI to the given network interface:

# configures ROS_MASTER_URI=master_hostname.local and ROS_IP=(ip on eth0)
ros_master eth0 master_hostname.local

Call ros_reset to unset ROS_IP and ROS_MASTER_URI.

Examples

A few functions, that are designed for use at Centrale Nantes, show how to combine the previous tools:

• ros_baxter: configure ROS 1 to connect on Baxter's ROSMASTER through ethernet, restrict ROS 2 to localhost
• ros_turtle #turtle: configure ROS 2 to use the same ROS_DOMAIN_ID as our Turtlebots and restrict to Wifi. If another argument is given, relies on a discovery server on the Turtlebot.

Any similar function can be defined and used with the custom prompt and stored settings. The function should start with ros_ and are assumed to be exclusive (only the latest called ros_ function is stored for future terminals).

Best practices: the .bashrc file should just source the file

The rosXws or network function calls should not be put in the .bashrc but used in conjunction with the -k setting that forwards any setting to new terminals. This way there is no need to change the .bashrc file anymore.

If you have many workspaces that you source or not source depending on the project you work on, the simplest approach is probably to have several ros2_workspaces= lines in the .bashrc where you uncomment the one you currently want to use:

ros2_workspaces="/opt/ros/humble /some/path/to/underwater_sim/workspace"
ros2_workspaces="/opt/ros/humble /some/path/to/another/amazing/set_of_packages"
ros2_workspaces="/opt/ros/humble /some/path/to/this_new_project" # <- the one that is used right now

At this point you should be rigourous enough to re-source all terminals to make sure they use the same workspaces.

Some bonus

Compiling while Gazebo is running

Gazebo can be quite resource-hungry which leads to longer compilation times when working on a node in parallel. The function gz_compile_watchdog, defined in ros_management.bash, will pause Gazebo when one of this processes is detected: cmake, c++, colcon, catkin.

IDE configuration

The ide folder includes a script to generate ad-hoc configuration files (raw CMake / ROS 1 / ROS 2) for Qt Creator and VS Code. With this, IDE's will just treat ROS packages as classical CMake, assuming catkin or colcon was called before to create and symlink the relevant files.