How to launch several ROS Docker terminals connected to the same container with all ROS commands working?

I launched Docker ROS in the main window through

sudo docker run -it osrf/ros:noetic-desktop-full

and then tried to open secondary terminal:

sudo docker exec -it <container_id> bash

, but a lot of commmands, like e.g. rostopic and roscore , do not work in the second terminal that I opened through exec. It just shows command not found when I type them.

>Solution :

You need to source your ROS environment once you have your shell in the container:

. /opt/ros/noetic/setup.bash

Afterwards your ros commands should work.