You're reading the documentation for a version of ROS 2 that has reached its EOL (end-of-life), and is no longer officially supported. If you want up-to-date information, please have a look at Galactic.
Running 2 nodes in a single docker container [community-contributed]
Pull the ROS docker image with tag “dashing-desktop”.
docker pull osrf/ros:dashing-desktop
Run the image in a container in interactive mode.
$ docker run -it osrf/ros:dashing-desktop root@<container-id>:/#
Your best friend is the
ros2 command line help now.
root@<container-id>:/# ros2 --help
E.g. list all installed packages.
root@<container-id>:/# ros2 pkg list (you will see a list of packages)
E.g. list all executables:
root@<container-id>:/# ros2 pkg executables (you will see a list of <package> <executable>)
Run a minimal example of 2 C++ nodes (1 topic subscriber
listener, 1 topic publisher
talker) from the package
demo_nodes_cpp in this container:
ros2 run demo_nodes_cpp listener & ros2 run demo_nodes_cpp talker