Add launch file with port arg

[jccurtis]

I added a launch file (ROS1) with an argument to specify the port. It is installed to the shared package dest so one can run:

roslaunch rosboard rosboard.launch port:=####

In my case this is needed to use the --wait arg to tell roslaunch to wait for roscore before starting the node.

[dheera]

Hi @jccurtis thanks for this. I'd like to understand can you please elaborate on why this is useful as opposed to just rosrun rosboard rosboard_node _port:=####?

[jccurtis]

Hey @dheera. Thanks for taking a look. My use case is rather specific because I have rosboard running in a docker container and waiting for a different container running roscore to spin up the roscore process. I've had much more success with roslaunch and --wait to correctly get the clock from roscore when running data from a bag with the --clock argument. I understand that rosrun will wait for roscore but it doesn't get the correct clock (or it is a race condition and will sometimes based on startup time.) I am using the launch file from our fork and I thought it might be helpful for others accustomed to launch files. I totally understand if you see this as bloat to your project. Really nice work here btw 👏

[dheera]

Thank you!