[CM] Add controller_manager activity topic

[saikishor]

As discussed in the ros2_control WG meeting on 15th Jan 2025

I've added a topic to the CM inorder to publish information on changes in the CM. This is quite useful to have when developing applications that need to be dynamic enough with the changes in CM. Right now, the only way is to spam the CM with lot of service requests.

It should look something like the below

---
header:
  stamp:
    sec: 1737128088
    nanosec: 39885323
  frame_id: ''
controllers:
- name: forward_position_controller
  state:
    id: 2
    label: inactive
- name: position_controller
  state:
    id: 3
    label: active
- name: joint2_position_controller
  state:
    id: 3
    label: active
- name: joint1_position_controller
  state:
    id: 3
    label: active
- name: joint_state_broadcaster
  state:
    id: 3
    label: active
hardware_components:
- name: RRBot
  state:
    id: 3
    label: active
---

[codecov]

Codecov Report

Attention: Patch coverage is 94.80519% with 4 lines in your changes missing coverage. Please review.

Project coverage is 89.56%. Comparing base (3aa38b0) to head (30e8c2c).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...ontroller_manager/test/test_controller_manager.cpp	90.00%	0 Missing and 3 partials ⚠️
controller_manager/src/controller_manager.cpp	96.77%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2006      +/-   ##
==========================================
+ Coverage   89.54%   89.56%   +0.02%     
==========================================
  Files         139      139              
  Lines       15125    15195      +70     
  Branches     1283     1290       +7     
==========================================
+ Hits        13543    13609      +66     
+ Misses       1096     1094       -2     
- Partials      486      492       +6     

Flag	Coverage Δ
unittests	89.56% <94.80%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
.../include/controller_manager/controller_manager.hpp	96.87% <ø> (ø)
hardware_interface/src/resource_manager.cpp	76.40% <100.00%> (+0.23%)	⬆️
controller_manager/src/controller_manager.cpp	76.70% <96.77%> (+0.42%)	⬆️
...ontroller_manager/test/test_controller_manager.cpp	95.87% <90.00%> (-0.23%)	⬇️

... and 3 files with indirect coverage changes

[christophfroehlich]

great addition. Should we also add a publisher section here describing this?
https://control.ros.org/rolling/doc/ros2_control/controller_manager/doc/userdoc.html#subscribers

[saikishor]

great addition. Should we also add a publisher section here describing this?
https://control.ros.org/rolling/doc/ros2_control/controller_manager/doc/userdoc.html#subscribers

Actually, I want to document all the Services and Publishers from the controller manager. I don't know if I have to do it in this PR or a separate PR. What's your opinion @christophfroehlich

[christophfroehlich]

great addition. Should we also add a publisher section here describing this?
https://control.ros.org/rolling/doc/ros2_control/controller_manager/doc/userdoc.html#subscribers

Actually, I want to document all the Services and Publishers from the controller manager. I don't know if I have to do it in this PR or a separate PR. What's your opinion @christophfroehlich

please add the docs for this new publisher with this PR.

[saikishor]

@christophfroehlich done! 👍🏾

[christophfroehlich]

Thx!

[bmagyar]

I understand that this is easier to integrate now but shouldn't we simply make these part of the constructors?

[saikishor]

Sure, when we branch off, we will certainly do that :)

[mergify]

This pull request is in conflict. Could you fix it @saikishor?