Separation artifacts/systems

[fmrico]

Hi,

This PR contains an update to separate artifacts and systems, as talked with @ipa-nhg .

This PR also contains a proposal for the .rossystem files. Examples:

---
rossdl_simple_test:
  fromGitRepo: "https://github.com/jane-doe/project_example.git:branch"
  systems:
    system_1:
      nodes: [rossdl_simple_test::image_filter, rossdl_simple_test::consumer]
      connections:
        - [/image_filter/image_out, /consumer/image_in]
        - [/image_filter/description_out, /consumer/description_in]
        - [/camera/rgb/image_raw, /image_filter/image_in]
        - [/consumer/image_out, /other_node/image_in]
      parameters:
        - [/image_filter/description_label, 'image raw']
        - [/*/use_sim_time, True]
    system_2:
      nodes: [rossdl_simple_test::image_filter, rossdl_simple_test::consumer]
      connections:
        - [/image_filter/image_out, /consumer/image_in]
        - [/image_filter/description_out, /consumer/description_in]
      parameters:
        - [/image_filter/description_label, 'image compressed']
        - [/*/use_sim_time, False]   

---
system_a:
  fromGitRepo: "https://github.com/jane-doe/project_example.git:branch"
  systems:
    system_a_basic:
      nodes: [system_a::image_filter]
      connections:
        - [/camera/rgb/image_raw, /image_filter/image_in]
      parameters:
        - [/image_filter/description_label, 'image raw']
        - [/*/use_sim_time, False]

---
application_1:
  fromGitRepo: "https://github.com/jane-doe/project_example.git:branch"
  systems:
    app_1_system_1:
      nodes: [system_a::image_filter, system_b::consumer]
      connections:
        - [/image_filter/image_out, /consumer/image_in]
        - [/image_filter/description_out, /consumer/description_in]
        - [/camera/rgb/image_raw, /image_filter/image_in]
        - [/consumer/image_out, /other_node/image_in]
      parameters:
        - [/image_filter/description_label, 'image raw']
        - [/*/use_sim_time, False]
    app_1_system_2:
      nodes: [system_a::image_filter, system_b::consumer]
      connections:
        - [/image_filter/image_out, /consumer/image_in]
        - [/image_filter/description_out, /consumer/description_in]
      parameters:
        - [/image_filter/description_label, 'image compressed']
        - [/*/use_sim_time, False]

---
application_2:
  fromGitRepo: "https://github.com/jane-doe/project_example.git:branch"
  systems:
    app_2_system_1:
      subsystems: [system_a::system_a_basic]
      nodes: [system_b::consumer]
      connections:
        - [/image_filter/image_out, /consumer/image_in]
        - [/image_filter/description_out, /consumer/description_in]
        - [/consumer/image_out, /other_node/image_in]
      parameters:
        - [/*/use_sim_time, False]

---
application_3:
  fromGitRepo: "https://github.com/jane-doe/project_example.git:branch"
  systems:
    app_3_system_1:
      subsystems: [application_2::app_2_system_1]
      nodes: []
      connections: []
      parameters: []

Let's discuss in this PR any modification until haveing an agreement :)

[ipa-nhg]

Thanks a lot for opening the discussion :)

We made some progress also from our side on the models, The current model looks like this:

system:
  nodes:
    image_filter:
      from: "rossdl_test.image_filter"
      interfaces:
        - image_out: pub-> "image_filter::image_out"
        - description_out: pub-> "image_filter::description_out"
        - camera_info: sc-> "image_filter::camera_info"
        - image_info: sc-> "image_filter::camera_info"
      parameters:
       - description: "image_filter::description_label"
         value: "Label"
    consumer:
      from: "rossdl_test.consumer"
      interfaces:
       - image_in: sub-> "consumer::image_in"
       - description_in: sub->"consumer::description_in"
  processes:
    process1:
      nodes: [ image_filter, consumer ]
      threads: 2
  connections:
    -[image_out,image_in]
    -[description_out, description_in]

The main difference between your suggestion and mine is that I define the nodes in detail, the idea is to be able to rename or change namespaces, do you think this is needed? Ideally, I should modify my models to support both versions.

I am also a bit confused about the namespaces you are using for the node (i.e., system_a::image_filter), the nodes come from a ROS packages ( from the point of view of the models from a .ros2 file), or am I mixing things here?

About the composition of subsystems, I have also an open thread, but I am not yet happy. At IPA these days we are applying the models to a real use case, a UR manipulator with sensors and a gripper. Thanks to this example we are debugging and cleaning up our concept. I will ping you as soon as we have a well-tested version.

[fmrico]

Ok, @ipa-nhg , my idea is adapting to all you consider.