roslaunch/2008-09-18 roslaunch Specification Review

Package Developer: KenConley

Reviewers:

• StuGlaser

• BrianGerkey

• TullyFoote

• EricBerger

• MorganQuigley

Agenda

The focus of this review will focus on the features that roslaunch provides as well as the XML format of the roslaunch files. In particular:

• What remaining features are necessary?
• What use cases is roslaunch poor at?
• Is roslaunch sufficient for our PR2 needs?

These are the currently open feature/bug tickets:

• Support for xmlparam/yamlparam files

• Re-implementing SSH support

Please add your questions/answers here:

Package Specification

• XML format documentation

• Doxygen

Key features

• Establish the state of the ROS runtime environment, including the master, parameters, nodes, and services
• Correctly tear down the ROS runtime environment
• Restart ROS nodes as necessary
• Support multi-machine setups

Dependencies

• rostools : library for manipulating ROS environment

Testing strategy

• XML-parsing unit tests against XML files
• Implicit integration testing via rostest

Minutes

• rosout is preferred over routing console output to screen.
• Getting console output from remote processes to the local screen is not a priority. rosout is the solution there.
• Morgan uses roslaunch on each machine, and it works "awesome".
• Groups cannot be combined; i.e., a group can be declared only in one place.
• Startup errors (e.g., executable bit not set) are communicated by the "process died" message to console from roslaunch. If respawn is set, you may get a fast sequence of startup / die messages.
• Once support is added for referencing xmlparam and yamlparam files, roslaunch will call out to them (i.e., not reimplement that functionality)
• After roslaunch dies, parameters stay up; use the master tag to control this behavior.
• Will eventually add 'roscore' that brings up rosout, master, and param server. Works in a singleton fashion, not restarting any of these core services.
• Can we extend the singleton behavior to user-defined ros nodes? No need, because the master will kill the first instance of two nodes with the same name already.
• We could add the 'start' attribute to the node tag, allowing the user to specify start or restart. No, don't do that; instead use multiple roslaunch files (either with multiple invocations of roslaunch, or with one invocation and use of the include tag)
• How is include pathing done? It happens rospack-relative. All includes happen on the local machine.

Conclusion

PASSED!

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