ROS_network_interceptor

Prerequisites

Make sure you are able to launch the talker and listener example from FogROS2_bootcamp Follow Part 1 and stop after step 13 in Part 2 to be able to run this example locally.

Step 1:

After you have verified that you are able to launch the talker and listerner axample, terminate it and in that same directory run

echo $ROS_DOMAIN_ID

You should see a number ranging from 0 and 101, inclusive outputted. However, if there isn't one you can set one by running

export ROS_DOMAIN_ID={value}

Step 2:

Open up a new tab in temrinal and following the same steps done in the prerequisites section, but this time stop at step 10 in Part 2 of the FogROS2_bootcamp. We will be building another docker container that will intercept the talker and listener from the first one.

Step 3:

Once we reached step 10, we go back to the first terminal and start up the talker and listener example by running

ros2 launch talker.local.launch.py

Step 4:

While that is running we go to the second docker container and run the following command passing in the value we saw/set form Step 1.

. test_interuptor.sh {value} 

After 5 seconds this will terminate on its own

Step 5:

Now you will see that there was a new file created called hacked_topic_messages.txt. Open this file and you will be able to see the messages being sent from the first docker container!

nano hacked_topic_messages.txt