Is it possible to run the Rosbridge as standalone Websocket-Server?
Instead of running the rosbridge-suite as a ROS 2-node I'd like to run it as standalone service on a cloud instance that my robot connects to. So ideally I would have a ROS 2-node that gets the domain/IP of my server instance in the cloud where I then run the WebSocket-Server so a browser can connect to that as well.
Only quick workaround for ROS-1 that I can think of is that I run a second roscore in the cloud and I code a custom ros-node on the robot so I can forward everything I need from the local roscore on the robot to the cloud and then to a WebServer and from there to the browser of the user but that will not work for ROS 2 because there is no ROS master with a fixed IP I could connect to.
Is there another way or do I need to build my own ros-node that connects to a WebServer that I build as alternative solution?
Is ROS necessary on the cloud server? Does something like the websockets python package suffice?
Yes, that would be another alternative solution. But it would be something where I have to program the server-part myself. Instead of python-websockets I would probably build something with TypeScript ontop of express and its WebSocket implementation or use aiohttp for Python but I am looking for a solution that I can just use without the need to code the protocol and just have a high-level api, like roslibpy or roslib.js but as a server, not a client. If there is no solution yet I will start a new project and build that...
I am not sure I understand the problem correctly. Do you want to have a remote websocket server with custom messages/interface. Inside the ROS node you can connect to that, but the connection is separate from ROS. Or do you want to access ROS message/service/actions remotely using ros_bridge?
I want to access my robot from the web. To simplify network issues I like to run roswebbridge in the cloud because I don't want to run a websocket-server on the robot (its IP can change and firewall might get tricky, so I think it makes sense to run the websocket-server standalone in the cloud).
I don't want a custom message/interface but I think I need to build one because there is nothing that allows me to access the ROS-messages/actions/services remotely as standalone solution (the ros-websuite runs as a ros node, so it has to run on the robot for ros-2 or with a second ros1-roscore in the cloud that I forward the robot data to).
Thank you, that clarifies the intent. You could also make a custom client that allows the server to connect to ros_bridge. It can share the robot's IP address for example. That might save you reimplementing the ros_bridge solution. Another possible solution might be to give the robot a static IP address. The cannot comment on the firewall rules, because they are highly situational.
Thank you. So I think my lowest-effort option is to run ros2 on the robot, and another ros2-instance on the cloud that also runs ros-webbridge so I can run roslibpy on the robot to forward my local robot topics/actions/services from the robot to the cloud and also connect to that cloud instance from a browser using roslib.js.