This package exposes several ROS services that require some dependencies to fulfill the requests. They are listed below, separated in categories [ROS1 package and module used in brackets]:

• Services requiring introspection over ROS system (as in rosservice, rostopic, etc). This functionality should be found in ros2cli:
  • Topics: active topics in system [rosgraph.masterapi] → ros2topic.api.get_topic_names.
  • Topics_for_type: list of topics of a given type [rosservice.get_topic_type].
  • Services: list of services being advertised [rosservice.get_service_list.
  • Services_for_type: services that are publishing a given type [rosservice.rosservice_find].
  • Nodes: List of all registered nodes [rosnode.get_node_names].
  • Node_details: Returns node description (subscriptions, publications, services) [rosgraph.masterapi].
  • Action_servers: List of action servers [same as Topics service, nothing new].
  • Topic_type: returns the type of a given topic [rostopic.get_topic_type].
  • Service_type: returns the type of a given service [rosservice.get_service_type].
  • Publishers: returns list of node names publishing to a given topic [rosgraph.masterapi].
  • Subscribers: returns list of node names subscribing to a given topic [rosgraph.masterapi].
  • Service_providers: returns a list of node names that are advertising a service with the specified type [rosgraph.masterapi].
  • Service_node: returns name of the node providing a given service [rosservice.get_service_node].
  • Service_host: returns the name of the machine that is hosting the given service [rosservice.get_service_uri].
• Services depending on roslib via rosbridge_library.internal (roslib.launcher.load_manifest, which internally depends on RosPack):
  • Message_details: returns typedef for a message type.
  • Service_request_details: returns typedef for a service request type.
  • Service_response_details: returns typedef for a service response type.
• Parameter handling services; needs parameter adaptation to ROS2 (parameters are associated to nodes in ROS2 as opposed to ROS1, which may result in slight changes wrt. current API):
  • Set_param
  • Get_param
  • Has_param
  • Search_param
  • Delete_param
  • Get_param_names
• Misc
  • Get_time: equivalent to rospy.get_rostime().

The idea to start with is to depend on packages in ros2cli repository and make use of its functionality as it is (mainly inside api python packages). As a second step, one possibility would be to refactor ros2cli (repository) a bit to extract the functionality to be reused here from the command line part of the code (i.e. don't depend on ros2cli package itself). This shall be analyzed throughout the implementation.