Yaml suppport

.github/workflows/industrial_ci_action.yml

@@ -44,4 +44,3 @@ jobs:
           # Added back so testing without Dockerfile can be done
           ROS_DISTRO: ${{ matrix.ROS_DISTRO }}
           ROS_REPO: ${{ matrix.ROS_REPO }}
-

config/pub.yaml

@@ -0,0 +1,12 @@
+mqtt_ros_bridge:
+  ros__parameters:
+    turtle_pub: 
+      topic: "/turtle1/cmd_vel"
+      type: "geometry_msgs.msg:Twist"
+      publish_on_ros: True
+
+    yippee: 
+      topic: "foo"
+      type: "std_msgs.msg:String"
+      publish_on_ros: True
+      use_ros_serializer: True

config/sub.yaml

@@ -0,0 +1,12 @@
+mqtt_ros_bridge:
+  ros__parameters:
+    turtle_pub: 
+      topic: "/turtle1/cmd_vel"
+      type: "geometry_msgs.msg:Twist"
+      publish_on_ros: False
+
+    yippee: 
+      topic: "foo"
+      type: "std_msgs.msg:String"
+      publish_on_ros: True
+      use_ros_serializer: True

launch/demo_pub_bridge_launch.py

@@ -0,0 +1,36 @@
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch.actions import SetEnvironmentVariable
+from launch.launch_description import LaunchDescription
+from launch_ros.actions import Node
+
+
+def generate_launch_description() -> LaunchDescription:
+    """
+    Generate LaunchDescription for MQTT ROS bridge.
+
+    Returns
+    -------
+    LaunchDescription
+        Launches bridge_node.
+
+    """
+    config = os.path.join(
+        get_package_share_directory('mqtt_ros_bridge'),
+        'config',
+        'pub.yaml'
+    )
+
+    run_bridge_node = Node(
+        package='mqtt_ros_bridge',
+        executable='bridge_node',
+        emulate_tty=True,
+        output='screen',
+        arguments=[config]
+    )
+
+    return LaunchDescription([
+        SetEnvironmentVariable("ROS_DOMAIN_ID", "2"),
+        run_bridge_node
+    ])

launch/demo_sub_launch.py

@@ -0,0 +1,45 @@
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch.actions import SetEnvironmentVariable
+from launch.launch_description import LaunchDescription
+from launch_ros.actions import Node
+
+
+def generate_launch_description() -> LaunchDescription:
+    """
+    Generate LaunchDescription for MQTT ROS bridge.
+
+    Returns
+    -------
+    LaunchDescription
+        Launches bridge_node.
+
+    """
+    config = os.path.join(
+        get_package_share_directory('mqtt_ros_bridge'),
+        'config',
+        'sub.yaml'
+        )
+
+    run_bridge_node = Node(
+        package='mqtt_ros_bridge',
+        executable='bridge_node',
+        emulate_tty=True,
+        output='screen',
+        arguments=[config]
+    )
+
+    turtle_sim = Node(
+        package='rqt_robot_steering',
+        executable='rqt_robot_steering',
+        emulate_tty=True,
+        parameters=[{"topic": "/turtle1/cmd_vel"}],
+        output='screen'
+    )
+
+    return LaunchDescription([
+        SetEnvironmentVariable("ROS_DOMAIN_ID", "1"),
+        run_bridge_node,
+        turtle_sim
+    ])

launch/demo_turtle_sim_launch.py

@@ -0,0 +1,26 @@
+from launch.actions import SetEnvironmentVariable
+from launch.launch_description import LaunchDescription
+from launch_ros.actions import Node
+
+
+def generate_launch_description() -> LaunchDescription:
+    """
+    Generate LaunchDescription for MQTT ROS bridge.
+
+    Returns
+    -------
+    LaunchDescription
+        Launches bridge_node.
+
+    """
+    turtle_sim = Node(
+        package='turtlesim',
+        executable='turtlesim_node',
+        emulate_tty=True,
+        output='screen'
+    )
+
+    return LaunchDescription([
+        SetEnvironmentVariable("ROS_DOMAIN_ID", "2"),
+        turtle_sim
+    ])

mqtt_ros_bridge/bridge_node.py

@@ -1,45 +1,64 @@
-from dataclasses import dataclass
-from typing import Any, Callable, Generic, Type
+import os
+import sys
+from typing import Any, Callable, Generic, cast
 
 import paho.mqtt.client as MQTT
 import rclpy
-
 from rclpy._rclpy_pybind11 import RMWError
 from rclpy.node import Node
+# TODO this breaks humble
+from rclpy.parameter import Parameter, parameter_dict_from_yaml_file
 from rclpy.publisher import Publisher
-from rclpy.subscription import Subscription
-from std_msgs.msg import String
 
 from mqtt_ros_bridge.msg_typing import MsgLikeT
-from mqtt_ros_bridge.serializer import ROSDefaultSerializer, Serializer
+from mqtt_ros_bridge.serializer import JSONSerializer, ROSDefaultSerializer
+from mqtt_ros_bridge.util import lookup_message
 
 
-@dataclass
-class TopicInfo(Generic[MsgLikeT]):
+class TopicMsgInfo(Generic[MsgLikeT]):
     """Metadata about a single topic."""
 
-    name: str
-    msg_type: Type[MsgLikeT]
-    # Should Serializer also be generic across MsgLikeT?
-    serializer: type[Serializer]
-    publish_on_ros: bool
+    def __init__(self, topic: str, msg_object_path: str,
+                 publish_on_ros: bool, use_ros_serializer: bool = True) -> None:
+
+        self.topic = topic
+        self.msg_type: MsgLikeT = cast(MsgLikeT, lookup_message(msg_object_path))
+        self.publish_on_ros = publish_on_ros
+        self.serializer = ROSDefaultSerializer if use_ros_serializer else JSONSerializer
 
+    def __str__(self) -> str:
+        return (f"Topic: {self.topic}, Message Type: {self.msg_type}, Publish on ROS:"
+                f"{self.publish_on_ros}, Serializer: {self.serializer}")
 
-TOPICS: dict[str, TopicInfo] = {
-    '/turtle1/cmd_vel': TopicInfo('/turtle1/cmd_vel', String, ROSDefaultSerializer, False),
-    # 'sub_topic': TopicInfo('sub_topic', String, ROSDefaultSerializer, False)
-}
 
 MQTT_PORT = 1883
 MQTT_KEEPALIVE = 60
 
+PARAMETER_TOPIC = "topic"
+PARAMETER_TYPE = "type"
+PARAMETER_PUBLISH_ON_ROS = "publish_on_ros"
+PARAMETER_USE_ROS_SERIALIZER = "use_ros_serializer"
+
 
 class BridgeNode(Node):
     """Node to bridge MQTT and ROS."""
 
-    def __init__(self) -> None:
+    def __init__(self, args: list[str]) -> None:
         super().__init__('mqtt_bridge_node')
 
+        # TODO get from parameters
+        # DEBUG = True
+
+        print(args)
+
+        if (len(args) != 2 and "--ros-args" not in args) or not (len(args) == 3 and
+                                                                 "--ros-args" in args):
+            raise ValueError("To many arguments given")
+
+        self.topics = self.topic_info_from_parameters(args[1])
+
+        self.get_logger().info(str(self.topics))
+
         self.get_logger().info('Creating MQTT ROS bridge node')
 
         self.mqtt_client = MQTT.Client()
@@ -48,34 +67,64 @@ def __init__(self) -> None:
         self.mqtt_client.loop_start()
 
         self.ros_publishers: dict[str, Publisher] = {}
-        self.ros_subscriptions: list[Subscription] = []
 
-        for topic_info in TOPICS.values():
+        for topic_info in self.topics.values():
             if topic_info.publish_on_ros:
-                publisher = self.create_publisher(topic_info.msg_type, topic_info.name, 10)
-                self.ros_publishers[topic_info.name] = publisher
-                self.mqtt_client.subscribe(topic_info.name)
+                publisher = self.create_publisher(topic_info.msg_type, topic_info.topic, 10)
+                self.ros_publishers[topic_info.topic] = publisher
+                self.mqtt_client.subscribe(topic_info.topic)
             else:
                 callback = self.make_ros_callback(topic_info)
-                subscription = self.create_subscription(
-                    topic_info.msg_type, topic_info.name, callback, 10)
-                self.ros_subscriptions.append(subscription)
+                # TODO proper QOS?
+                self.create_subscription(topic_info.msg_type, topic_info.topic, callback, 10)
 
         self.mqtt_client.on_message = self.mqtt_callback
 
-    def make_ros_callback(self, topic_info: TopicInfo[MsgLikeT]) -> Callable[[MsgLikeT], None]:
+    def topic_info_from_parameters(self, config: str) -> dict[str, TopicMsgInfo]:
+
+        config = os.path.expanduser(config)
+        topic_infos: dict[str, TopicMsgInfo] = {}
+
+        params: dict[str, Parameter] = {}
+        dictionary = parameter_dict_from_yaml_file(config)
+
+        for key, parameter_msg in dictionary.items():
+            params[key] = Parameter.from_parameter_msg(parameter_msg)
+
+        unique_names: set[str] = set()
+        for names in params.keys():
+            # TODO Check that right half matches PARAMETER_*
+            unique_names.add(names.split(".")[0])
+
+        for name in unique_names:
+
+            if params.get(f"{name}.{PARAMETER_USE_ROS_SERIALIZER}", None):
+                ros_serialiser = params[f"{name}.{PARAMETER_USE_ROS_SERIALIZER}"].value
+            else:
+                ros_serialiser = False
+
+            topic_infos[params[f"{name}.{PARAMETER_TOPIC}"].value] = (TopicMsgInfo(
+                params[f"{name}.{PARAMETER_TOPIC}"].value,
+                params[f"{name}.{PARAMETER_TYPE}"].value,
+                params[f"{name}.{PARAMETER_PUBLISH_ON_ROS}"].value,
+                ros_serialiser
+            ))
+
+        return topic_infos
+
+    def make_ros_callback(self, topic_info: TopicMsgInfo[MsgLikeT]) -> Callable[[MsgLikeT], None]:
         """
         Create a callback function which re-publishes messages on the same topic in MQTT.
 
         Parameters
         ----------
-        topic_info : TopicInfo
+        topic_info : TopicMsgInfo
             information about the topic that the callback will publish on
 
         """
         def callback(msg: MsgLikeT) -> None:
-            self.get_logger().info(f'ROS RECEIVED: Topic: "{topic_info.name}" Payload: "{msg}"')
-            self.mqtt_client.publish(topic_info.name, topic_info.serializer.serialize(msg))
+            self.get_logger().info(f'ROS RECEIVED: Topic: "{topic_info.topic}" Payload: "{msg}"')
+            self.mqtt_client.publish(topic_info.topic, topic_info.serializer.serialize(msg))
 
         return callback
 
@@ -94,10 +143,10 @@ def mqtt_callback(self, _client: MQTT.Client,
             the message received over MQTT
 
         """
-        topic_info = TOPICS[mqtt_msg.topic]
+        topic_info = self.topics[mqtt_msg.topic]
 
         self.get_logger().info(
-            f'MQTT RECEIVED: Topic: "{topic_info.name}" Payload: "{mqtt_msg.payload!r}"')
+            f'MQTT RECEIVED: Topic: "{topic_info.topic}" Payload: "{mqtt_msg.payload!r}"')
 
         try:
             ros_msg = topic_info.serializer.deserialize(mqtt_msg.payload, topic_info.msg_type)
@@ -106,14 +155,14 @@ def mqtt_callback(self, _client: MQTT.Client,
                                    f'MQTT on topic "{mqtt_msg.topic}": "{mqtt_msg.payload!r}"')
             return
 
-        self.ros_publishers[topic_info.name].publish(ros_msg)
+        self.ros_publishers[topic_info.topic].publish(ros_msg)
 
 
 def main(args=None):
     """Run bridge node; used in ROS executable."""
     rclpy.init(args=args)
 
-    bridge_node = BridgeNode()
+    bridge_node = BridgeNode(sys.argv)
 
     rclpy.spin(bridge_node)
 

mqtt_ros_bridge/serializer.py

@@ -1,5 +1,4 @@
 from abc import ABC, abstractmethod
-from typing import Type
 
 from rclpy.serialization import deserialize_message, serialize_message
 
@@ -30,7 +29,7 @@ def serialize(message: MsgLike) -> bytes:
 
     @staticmethod
     @abstractmethod
-    def deserialize(serialized_message: bytes, message_type: Type[MsgLikeT]) -> MsgLikeT:
+    def deserialize(serialized_message: bytes, message_type: type[MsgLikeT]) -> MsgLikeT:
         """
         Deserialize the provided bytes into a ROS message of the provided type.
 
@@ -57,7 +56,7 @@ def serialize(message: MsgLike) -> bytes:
         return serialize_message(message)
 
     @staticmethod
-    def deserialize(serialized_message: bytes, message_type: Type[MsgLikeT]) -> MsgLikeT:
+    def deserialize(serialized_message: bytes, message_type: type[MsgLikeT]) -> MsgLikeT:
         return deserialize_message(serialized_message, message_type)
 
 
@@ -69,5 +68,5 @@ def serialize(message: MsgLike) -> bytes:
         return json_serialize(message)
 
     @staticmethod
-    def deserialize(serialized_message: bytes, message_type: Type[MsgLikeT]) -> MsgLikeT:
+    def deserialize(serialized_message: bytes, message_type: type[MsgLikeT]) -> MsgLikeT:
         return json_deserialize(serialized_message, message_type)

mqtt_ros_bridge/util.py

@@ -0,0 +1,17 @@
+from importlib import import_module
+from typing import cast
+
+from mqtt_ros_bridge.msg_typing import MsgLike
+
+
+def lookup_message(object_path: str, package: str = 'mqtt_ros_bridge') -> MsgLike:
+    """Lookup message from a some.module:object_name specification."""
+    return cast(MsgLike, _lookup_object(object_path, package))
+
+
+def _lookup_object(object_path: str, package: str = 'mqtt_ros_bridge') -> object:
+    """Lookup object from a some.module:object_name specification."""
+    module_name, obj_name = object_path.split(":")
+    module = import_module(module_name, package)
+    obj = getattr(module, obj_name)
+    return obj

package.xml

@@ -20,6 +20,7 @@
   <test_depend>test_msgs</test_depend>
   <test_depend>python3-pytest</test_depend>
 
+
   <export>
     <build_type>ament_python</build_type>
   </export>