[ros2] Port gazebo launch scripts to ROS2 (ros-simulation#962)

* [ros2] Port gazebo launch scripts to ROS2

* Add gdb and valgrind option

* Use shell command for extra gazebo args

gazebo_ros/launch/gazebo.launch.py

@@ -0,0 +1,35 @@
+# 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 Gazebo server and client with command line arguments."""
+
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import ThisLaunchFileDir
+
+
+def generate_launch_description():
+
+    # (TODO) Allow conditional include of gzserver and gzclient, once supported
+    # https://github.com/ros2/launch/issues/303
+    return LaunchDescription([
+        IncludeLaunchDescription(
+            PythonLaunchDescriptionSource([ThisLaunchFileDir(), '/gzserver.launch.py']),
+        ),
+
+        IncludeLaunchDescription(
+            PythonLaunchDescriptionSource([ThisLaunchFileDir(), '/gzclient.launch.py']),
+        ),
+    ])

gazebo_ros/launch/gzclient.launch.py

@@ -0,0 +1,82 @@
+# 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 Gazebo client with command line arguments."""
+
+from os import environ
+
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.actions import ExecuteProcess
+from launch.substitutions import LaunchConfiguration
+from launch.substitutions import PythonExpression
+
+from scripts import GazeboRosPaths
+
+
+def generate_launch_description():
+    model, plugin, media = GazeboRosPaths.get_paths()
+
+    if 'GAZEBO_MODEL_PATH' in environ:
+        model += ':'+environ['GAZEBO_MODEL_PATH']
+    if 'GAZEBO_PLUGIN_PATH' in environ:
+        plugin += ':'+environ['GAZEBO_PLUGIN_PATH']
+    if 'GAZEBO_RESOURCE_PATH' in environ:
+        media += ':'+environ['GAZEBO_RESOURCE_PATH']
+
+    env = {'GAZEBO_MODEL_PATH': model,
+           'GAZEBO_PLUGIN_PATH': plugin,
+           'GAZEBO_RESOURCE_PATH': media}
+
+    return LaunchDescription([
+        DeclareLaunchArgument('version', default_value='false',
+                              description='Set "true" to output version information'),
+        DeclareLaunchArgument('verbose', default_value='false',
+                              description='Set "true" to increase messages written to terminal'),
+        DeclareLaunchArgument('help', default_value='false',
+                              description='Set "true" to produce gzclient help message'),
+        DeclareLaunchArgument('extra_gazebo_args', default_value='',
+                              description='Extra arguments to be passed to Gazebo'),
+
+        # Specific to gazebo_ros
+        DeclareLaunchArgument('gdb', default_value='false',
+                              description='Set "true" to run gzserver with gdb'),
+        DeclareLaunchArgument('valgrind', default_value='false',
+                              description='Set "true" to run gzserver with valgrind'),
+
+        # Execute
+        ExecuteProcess(
+            cmd=[['gzclient',
+                 _boolean_command('version'), ' ',
+                 _boolean_command('verbose'), ' ',
+                 _boolean_command('help'), ' ',
+                 LaunchConfiguration('extra_gazebo_args'),
+                  ]],
+            output='screen',
+            additional_env=env,
+            shell=True,
+            prefix=PythonExpression(['"gdb -ex run --args" if "true" == "',
+                                     LaunchConfiguration('gdb'),
+                                     '"else "valgrind" if "true" == "',
+                                     LaunchConfiguration('valgrind'),
+                                     '"else ""']),
+        )
+    ])
+
+
+# Add boolean commands if true
+def _boolean_command(arg):
+    cmd = ['"--', arg, '" if "true" == "', LaunchConfiguration(arg), '" else ""']
+    py_cmd = PythonExpression(cmd)
+    return py_cmd