Once the cluster is up, either with the cluster setup bash script or otherwise, there are several helpful testing commands in ROS that we can take advantage of.
- Get into bash shell of pod (usually find which pod is acting up via `kubectl get pods`), can be done with `kubectl exec -it <pod_name> -- bash`. This will start a persistent bash terminal in the pod specified. Once inside a pod the file system can be viewed as any linux system (using `ls` and `cd`).
- To start using ROS commands, the workspace needs to be sourced first. The source command is `source /opt/ros_ws/devel/setup.bash` (depending on which image is in use, the location of ros_ws folder may change but it should be close to where the bash script started you).
- Now that the ros workspace has been sourced, all ros commands should work.
* To check what topics are available and or check if there is a ros master running `rostopic list` can be used which will return a list of all topics currently being published
* To output a particular message from a topic `rostopic echo /<topic_name>` can be used (forward slash is important).
* To check what nodes are currently running `rosnode list` can be used, this can be helpful for debugging.
* If any of the above commands come back with a `Unable to communicate with ROS_MASTER` it is likely that the environment was not sourced correctly, or that `roscore` has not been run yet (i.e. the base station pod is not up or can not be detected from the current pod).
## Handy Troubleshooting Commands
There are a number of non-intuitive kubernetes commands that are super helpful for specific tasks:
