Add basic composition launch demo

composition/CMakeLists.txt

@@ -192,4 +192,10 @@ if(BUILD_TESTING)
     ${generated_python_files})
 endif()
 
+# Install launch files.
+install(DIRECTORY
+  launch
+  DESTINATION share/${PROJECT_NAME}
+)
+
 ament_package()

composition/launch/composition_demo.launch

@@ -0,0 +1,44 @@
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Launch a talker and a listener in a component container."""
+
+from launch_ros import get_default_launch_description
+from launch_ros.actions import ComposableNodeContainer
+from launch_ros.descriptions import ComposableNode
+
+
+def generate_launch_description():
+    """Generate launch description with multiple components."""
+    launch_description = get_default_launch_description()
+
+    container = ComposableNodeContainer(
+            node_name='my_container',
+            node_namespace='',
+            package='rclcpp_components',
+            node_executable='component_container',
+            composable_node_descriptions=[
+                ComposableNode(
+                    package='composition',
+                    node_plugin='composition::Talker',
+                    node_name='talker'),
+                ComposableNode(
+                    package='composition',
+                    node_plugin='composition::Listener',
+                    node_name='listener')
+            ]
+    )
+
+    launch_description.add_action(container)
+    return launch_description

composition/package.xml

@@ -16,6 +16,7 @@
   <build_depend>std_msgs</build_depend>
 
   <exec_depend>example_interfaces</exec_depend>
+  <exec_depend>launch_ros</exec_depend>
   <exec_depend>rclcpp</exec_depend>
   <exec_depend>rclcpp_components</exec_depend>
   <exec_depend>rcutils</exec_depend>