Catmux

About

Catmux is a little helper to run a tmux session with multiple windows and panes with just one command. It is inspired and functionally very similar to tmuxinator, but without the project management feature which is in my opinion kind of an overhead.

Session configs can be stored anywhere and have to be given as an argument.

Motivation

In most of our ROS projects at work we use shell output for almost all nodes to get log information during runtime. Having all this in one window where you start your "Start it all"-launchfile makes it very hard to follow the log of a specific node. Starting everything in separate windows is quite a lot of work and requires documentation overhead in sense of documenting which launchfiles or nodes have to be started.

At a conference I caught the idea to use tmux scripting to orchestrate all this in one tmux session. However, quickly I noticed that creating these scripts is a daunting task as you'll have to type in a lot of commands over and over again and as soon as you wanted to do things a little different such as not starting a particular launchfile if a certain parameter was set, things got complicated.

I liked the yaml-syntax of tmuxinator, but that tool didn't quite hit the spot. I wanted to have something that can be easily integrated into a ROS project and I definitely wanted something that saves the config per project and not all configs at one central spot on a particular machine.

Installation

Catmux is a pure python package and the installation via pip3 install --user catmux is recommended.

You can also install it by cloning this repository and calling pip3 install --user . in the repository's root directory. If you use this option, please be aware that some examples behave differently if you have installed catmux this way and are calling it from the repository directory. Calling them from outside the directory (e.g. after leaving via cd) is fine and should result in the same behavior as with the recommended installation method.

Usage

Currently, there is no full-blown documentation, but the example config file in catmux/resources/example_session.yaml gives a detailed insight on possible commands.

Running the example the most simple way

After installation, you can run a simple example by calling the following command:

catmux_create_session $(python3 -m catmux.prefix)/example_session.yaml

To see further options, simply run it with argument -h:

$ catmux_create_session -h
usage: catmux_create_session [-h] [-n SESSION_NAME] [-t TMUX_CONFIG] [-d] [--overwrite OVERWRITE]
                             session_config

Create a new catmux session

positional arguments:
  session_config        Session configuration. Should be a yaml-file.

optional arguments:
  -h, --help            show this help message and exit
  -n SESSION_NAME, --session_name SESSION_NAME
                        Name used for the tmux session
  -t TMUX_CONFIG, --tmux_config TMUX_CONFIG
                        This config will be used for the tmux session
  -d, --detach          Start session in detached mode
  --overwrite OVERWRITE
                        Overwrite a parameter from the session config. Parameters can be specified
                        using a comma-separated list such as '--overwrite param_a=1,param_b=2'.

Full blown example

To make use of all catmux features, run the following example command:

catmux_create_session $(python3 -m catmux.prefix)/example_session.yaml \
  --tmux_config $(python3 -m catmux.prefix)/tmux_default.conf \
  --session_name example_session \
  --overwrite show_layouts=True,replacement_param="new catmux user"

Killing a catmux session

If you are not that familiar with tmux: To kill a session, simply type tmux kill-session in any terminal window. In the catmux/resources/tmux_default.conf there is a key-binding for that, see etc/readme_tmux.txt for details.

Tmux server to be used

By default, catmux spawns its own tmux server called catmux. Therefore, a simple tmux list-sessions (or tmux ls) will not list the catmux session. To list the catmux session, use tmux -L catmux list-sessions. You can change the server's name by specifying the -L <server_name> parameter to catmux_create_session. That mechanism ensures that the environment in which catmux_create_session is started, will be used inside the catmux session (as long as no other session previously exists on that particular tmux server).

To make things a bit easier, there is a convenience script installed with this package: catmux. It is basically a wrapper around tmux -L <server_name>. For example, you can

catmux attach # attach to the latest running catmux session
catmux ls # list current catmux sessions
catmux kill-session -t example_session # kill session 'target session'

In case you use another tmux server than catmux, you can set the environment variable CATMUX_DEFAULT_SERVER to that name and continue using the catmux script.

Migrating from the catkin version of catmux

With the spread of ROS2, the need for a catkin-independent catmux has emerged. Catmux is now a plain python package without the ROS integration. Therefore, it is installed via pip and no longer needs to be part of a catkin workspace. This opens the possibility to easily use catmux outside of robotics application, e.g. for server administration or other development tasks.

Catmux no longer has the package://<your_package_name> lookup capabilities. To achieve the same outcome, simply use rospack:

catmux_create_session $(rospack find <your_package_name>)/path/to/<your_catmux_session_config.yaml>

For ROS2, the same is achievable with ros2 pkg prefix but the yaml has to be installed (similar to, for example, a launch file) and the installation path has to be specified:

catmux_create_session $(ros2 pkg prefix <your_package_name>)/path/to/the/installed/<your_catmux_session_config.yaml>

# for example: $ catmux_create_session $(ros2 pkg prefix catmux_test_pkg)/share/catmux_test_pkg/catmux_session.yaml

fmauch/catmux