proxy Plugin

Related Links

Reference example:

• proxy_plugin

Plugin Overview

proxy_plugin is used for proxying and forwarding messages in Channels. The plugin supports independent type_support_pkg and allows specifying executors (which need to be thread-safe). During usage, the plugin will register one or more Channel Subscribers or Publishers based on the configuration.

The configuration items for the plugin are as follows:

Node	Type	Optional	Default	Purpose
type_support_pkgs	array	Required	[]	type support package configuration
type_support_pkgs[i].path	string	Required	“”	Path of the type support package
proxy_actions	array	Required	[]	Proxy forwarding configuration
proxy_actions[i].name	string	Required	“”	Proxy forwarding name
proxy_actions[i].options	object	Required	{}	Proxy forwarding configuration
proxy_actions[i].options.executor	string	Required	“”	Proxy forwarding executor
proxy_actions[i].options.topic_meta_list	array	Required	[]	Topics and types to be proxied
proxy_actions[i].options.topic_meta_list[j].topic_name	string	Required	“”	Topic to be proxied
proxy_actions[i].options.topic_meta_list[j].msg_type	string	Required	“”	Message type to be proxied
proxy_actions[i].options.topic_meta_list[j].pub_topic_name	array	Required	[]	Target topic after proxying

Note that proxy_plugin manages proxy forwarding actions in action units. Each proxy action can have its own executor, topics, and other parameters. During usage, appropriate resources can be allocated for each action based on actual data size and frequency.

Simple Example Configuration for Proxy Forwarding

The following is a simple example configuration that proxies messages from a topic with an http backend to two topics with zenoh and ros2 backends. For proxy_plugin, an executor needs to be specified for each action, and at the channel level, a backend needs to be specified for each subscribed topic and forwarded topic. For configurations of other related plugins, please refer to net_plugin, zenoh_plugin, and ros2_plugin;

aimrt:
  plugin:
    plugins:
      - name: proxy_plugin
        path: ./libaimrt_proxy_plugin.so
        options:
          type_support_pkgs:
            - path: ./libexample_pb_ts.so
          proxy_actions:
            - name: my_proxy
              options:
                executor: proxy_plugin_executor
                topic_meta_list:
                  - sub_topic_name: test_topic_http
                    pub_topic_name: [test_topic_zenoh, test_topic_ros2]
                    msg_type: pb:aimrt.protocols.example.ExampleEventMsg
      - name: zenoh_plugin
        path: ./libaimrt_zenoh_plugin.so
      - name: ros2_plugin
        path: ./libaimrt_ros2_plugin.so
        options:
          node_name: example_ros2_pb_chn_publisher_node
          executor_type: MultiThreaded # SingleThreaded/StaticSingleThreaded/MultiThreaded
          executor_thread_num: 2
      - name: net_plugin
        path: ./libaimrt_net_plugin.so
        options:
          thread_num: 4
          http_options:
          listen_ip: 127.0.0.1
          listen_port: 50081
  channel:
    backends:
      - type: http
      - type: zenoh
      - type: ros2
    sub_topics_options:
      - topic_name: test_topic_http
        enable_backends: [http]
    pub_topics_options:
      - topic_name: test_topic_zenoh
        enable_backends: [zenoh]
      - topic_name: test_topic_ros2
        enable_backends: [ros2]
    # ...