can we run rosbag2 record / play as a ROS2 node or component?

[hakuturu583]

Description

Hi, I an developing ROS2 application and I found rosbag2 packages has no executable and components to play or record topics.

Implementation Notes / Suggestions

adding player and recorder component by using rosbag2_cpp::Reader and rosbag2_cpp::Write

[emersonknapp]

Good call! It makes perfect sense to provide a node/component that can be used, rather than having to call it via the CLI (or write your own program). This should not be hard to implement, the trickiest part will be making it configurable by parameters instead of commandline options.

Implementation notes: create a transport_node component in rosbag2_transport library. Use parameters to configure its options. Setup of the record/playback itself will look similar to https://github.com/ros2/rosbag2/blob/master/rosbag2_transport/src/rosbag2_transport/rosbag2_transport_python.cpp#L224

[hakuturu583]

@emersonknapp Thank you for your advice!

[fujitatomoya]

I guess that we tend to support this feature as general class, that is why @emersonknapp put help wanted tag. (if i am not mistaken...) we would probably keep this open? 🤔

[emersonknapp]

It's looking like this will probably be possible in the Galactic release - the Recorder and Player are becoming nodes, which could be components, configurable with parameters.

[berndpfrommer]

I'm trying to use the Recorder in Galactic as a node, but alas the constructor throws an UnimplementedError.
The data I'm trying to record is so fast that rmw interprocess communications are too slow and data is dropped.
Using a composable node container would make it possible to record at full speed.

Is there any way to instantiate a Recorder as a composable node container?

From what I understand the composable node has to inherit from rclcpp::Node, and a specific constructor needs to be provided (which is the one that currently throws the UnimplementedError). I tried to instantiate the Recorder inside another node, but got weird errors regarding duplicate nodes.

I can get it to work by inheriting from Recorder, and then setting the right storage options, but only after modifying the rosbag2_transport::Recorder source code, see PR #892

[tonynajjar]

Hi! Any update on this? I really think it makes sense to offer a node with a service to start recording. We wrote our own Node and I'm sure many other also have, it would make sense to have a standard node we can contribute improvements to.

Some things I'd like to see:

• receive multiple record requests and process them simultaneously
• The service offers the same options as the CLI

[MichaelOrlov]

@tonynajjar No updates about this task. I am sorry, don't have resources for that for a while.
Help would be appreciated.

[MichaelOrlov]

This issue will be resolved in the #1419

[hakuturu583]

Thanks!