Add cmake helper functions for configuring / generating cmd / conf files

[scpeters]

Desired behavior

We currently have a lot of repeated boilerplate code in each library that generates the conf/*.yaml and cmd*.rb files. It would be nice to provide some cmake helper functions. We could install that with ign-tools since it is related to this package.

For example in ign-transport:

• https://github.com/ignitionrobotics/ign-transport/blob/ignition-transport11_11.0.0/conf/CMakeLists.txt
• https://github.com/ignitionrobotics/ign-transport/blob/ignition-transport11_11.0.0/src/cmd/CMakeLists.txt#L63-L108

and also in ign-plugin

• https://github.com/ignitionrobotics/ign-plugin/blob/0da6f078a3b98c3ac962378272dd29c80b70b119/loader/conf/CMakeLists.txt
• https://github.com/ignitionrobotics/ign-plugin/blob/0da6f078a3b98c3ac962378272dd29c80b70b119/loader/src/cmd/CMakeLists.txt

The helper functions should be able to generate separate files for installation and testing.

Alternatives considered

• We could add cmake helper functions to ign-cmake.
• We could continue with the current approach that involves lots of duplicate code.

Implementation suggestion

Additional context

[harshmahesheka]

Hey @scpeters, I tried adding macros to ign-tools rather thanign-cmakeas discussed here gazebosim/gz-cmake#225. I added the code in Utils.cmake but it's not working. Other macros in Utils.cmake are also not working (some of which are working are also mentioned in ign-cmake (like ign_add_executable)). Could you provide some examples or guidance on how to proceed?

[harshmahesheka]

Hey @scpeters, I tried adding macros to ign-tools rather thanign-cmakeas discussed here ignitionrobotics/ign-cmake#225. I added the code in Utils.cmake but it's not working. Other macros in Utils.cmake are also not working (some of which are working are also mentioned in ign-cmake (like ign_add_executable)). Could you provide some examples or guidance on how to proceed?

I figured out that you had to install the required cmake file and include it in ignition-config.cmake.in.I have raised a pr and would love for you and @j-rivero to review it.

[j-rivero]

Sorry for the silence Harsh, I was out some months when this issue/PRs landed. Back to this, seems to me like there was an agreement to move the features to gz-cmake instead of having it in gz-tools. May I have the details of that agreement or the reason why we need to put it under gz-cmake?

[harshmahesheka]

Sorry for the silence Harsh, I was out some months when this issue/PRs landed. Back to this, seems to me like there was an agreement to move the features to gz-cmake instead of having it in gz-tools. May I have the details of that agreement or the reason why we need to put it under gz-cmake?

There was a discussion on this issue during Gazebo weekly meets, and after that, I was instructed to re-move it to gz-cmake.

[harshmahesheka]

Hey @j-rivero, any updates on this? I can help if some changes need to be done before merging