Add an extension to expose DDS ports for ROS

setup.py

@@ -52,6 +52,7 @@
             'nvidia = rocker.nvidia_extension:Nvidia',
             'privileged = rocker.extensions:Privileged',
             'pulse = rocker.extensions:PulseAudio',
+            'ros = rocker.ros_extension:RosPorts',
             'ssh = rocker.ssh_extension:Ssh',
             'user = rocker.extensions:User',
             'x11 = rocker.nvidia_extension:X11',

src/rocker/ros_extension.py

@@ -0,0 +1,106 @@
+# Copyright 2019 Open Source Robotics Foundation
+
+# 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.
+
+from argparse import ArgumentTypeError
+import getpass
+import os
+from rocker.extensions import RockerExtension
+
+
+
+# From Section 9.6.2 of DDSI-RTPS Spec
+# https://www.omg.org/spec/DDSI-RTPS/2.5/PDF
+
+# TODO answer here too: https://answers.ros.org/question/347630/ros2-port-forwarding/
+
+
+DDS_PB = 7400
+DDS_DG = 250
+DDS_PG = 2
+DDS_d0 = 0
+DDS_d1 = 10
+DDS_d2 = 1
+DDS_d3 = 11
+
+def get_multicast_dds_ports(ros_domain_id):
+
+    discovery_multicast_port = DDS_PB + DDS_DG * ros_domain_id + DDS_d0
+    user_multicast_port = DDS_PB + DDS_DG * ros_domain_id + DDS_d2
+
+    return [discovery_multicast_port, user_multicast_port]
+
+def get_unicast_dds_ports(ros_domain_id, number_of_participants):
+
+    ports = []
+
+    for participant_id in range(number_of_participants):
+        discovery_unicast_port = DDS_PB + DDS_DG * ros_domain_id + DDS_d3 + DDS_PG * participant_id
+        user_unicast_port = DDS_PB + DDS_DG * ros_domain_id + DDS_d3 + DDS_PG * participant_id
+        ports.append(discovery_unicast_port)
+        ports.append(user_unicast_port)
+
+    return ports
+
+
+
+class RosPorts(RockerExtension):
+
+    name = 'ros_ports'
+
+    @classmethod
+    def get_name(cls):
+        return cls.name
+
+
+    def get_docker_args(self, cli_args):
+        args = ''
+        # only parameterized for testing
+        ros_domain_id_str = cli_args.get('ros_domain_id')
+        if not ros_domain_id_str:
+            ros_domain_id_str = os.environ.get('ROS_DOMAIN_ID', 0)
+        ros_domain_id = int(ros_domain_id_str)
+
+        ports_type = cli_args.get('ros_ports_type')
+        ports = []
+        if ports_type == 'multicast' or ports_type == 'both':   
+            ports += get_multicast_dds_ports(ros_domain_id)
+        if ports_type == 'unicast' or ports_type == 'both':
+            ports += get_unicast_dds_ports(ros_domain_id, cli_args.get('ros_ports_unicast_participants'))
+
+        for port in ports:
+            args += ' -p {port}'.format(**locals())
+        args += ' -e ROS_DOMAIN_ID={ros_domain_id_str}'.format(**locals())
+        return args
+
+    @staticmethod
+    def register_arguments(parser, defaults={}):
+        parser.add_argument('--ros-ports',
+            action='store_true',
+            default=defaults.get(RosPorts.get_name(), None),
+            help="Expose ROS ports for DDS from container")
+        parser.add_argument('--ros-domain-id',
+            action='store',
+            type=int,
+            default=defaults.get('ros_domain_id', None),
+            help="Override the ROS_DOMAIN_ID from the automatically detected one in the environment for mapping ROS Ports")
+        parser.add_argument('--ros-ports-type',
+            action='store',
+            choices=['multicast', 'unicast', 'both'],
+            default=defaults.get('ros_ports_type', 'multicast'),
+            help="Expose ports for unicast or multicast")
+        parser.add_argument('--ros-ports-unicast-participants',
+            action='store',
+            type=int,
+            default=defaults.get('ros_ports_unicast_participants', 1),
+            help="Set the number of unicast participants to map ports for.")