Add discovery server minimal example (#154)

* Add discovery server minimal example

Signed-off-by: Lucia Echevarria <[email protected]>

* Add discovery server minimal example (fixed)

Signed-off-by: Lucia Echevarria <[email protected]>

* Add discovery server minimal example (changed)

Signed-off-by: Lucia Echevarria <[email protected]>

* Add discovery server minimal example (changed fixed)

Signed-off-by: Lucia Echevarria <[email protected]>

* Final changes in structure of Discovery Server tutorial

Signed-off-by: Lucia Echevarria <[email protected]>

* Final changes in structure of Discovery Server tutorial (changes made)

Signed-off-by: Lucia Echevarria <[email protected]>

---------

Signed-off-by: Lucia Echevarria <[email protected]>
(cherry picked from commit 1ff9136)

docs/rst/tutorials/core/discoveryserver/discoveryserver_tutorials.rst

@@ -0,0 +1,12 @@
+.. _tutorials_discoveryserver_tutorials:
+
+Discovery Server Tutorials
+===========================
+
+This section provides some tutorials for creating and utilizing the *FastDDS Discovery Server* to avoid multicast communication in ROS 2 deployments.
+They will serve as the starting point for gaining proficiency in working with ROS 2 and the FastDDS middleware.
+
+.. toctree::
+    :maxdepth: 1
+
+    discoveryserverminimalexample/discovery_server_minimal_example

docs/rst/tutorials/core/discoveryserver/discoveryserverminimalexample/discovery_server_minimal_example.rst

@@ -0,0 +1,86 @@
+.. _tutorials_deployment_discovery_server_minimal_example:
+
+Discovery Server Minimal Example
+=================================
+
+.. contents::
+    :depth: 2
+    :local:
+    :backlinks: none
+
+Background
+----------
+
+By default, ROS 2 uses the Simple Discovery Protocol (SDP), which relies on multicast communication to discover other nodes.
+While SDP is suitable for many scenarios, it may not be the best choice in complex and large-scale network configurations.
+This is where the Fast DDS Discovery Server comes into play. Fast DDS offers an alternative discovery mechanism that allows ROS 2 nodes to connect to a Discovery Server.
+This server acts as a centralized point for node registration and discovery, providing more flexibility and control in managing the network of nodes and is particularly advantageous in scenarios such as:
+
+* Large networks
+
+* Complex networks
+
+* WiFi networks
+
+In this tutorial, we will explore how to set up and use the Fast DDS Discovery Server with ROS 2, enabling robust and dynamic node discovery communication.
+
+.. figure:: /rst/figures/tutorials/core/discovery_server/Discovery_Server.svg
+   :align: center
+   :scale: 150%
+
+
+Prerequisites
+-------------
+
+It is required to have previously installed Vulcanexus using one of the following installation methods:
+
+* `Linux binary installation <https://docs.vulcanexus.org/en/latest/rst/installation/linux_binary_installation.html>`__
+* `Linux installation from sources <https://docs.vulcanexus.org/en/latest/rst/installation/linux_source_installation.html>`__
+* `Docker installation <https://docs.vulcanexus.org/en/latest/rst/installation/docker.html>`__
+
+
+Run this tutorial
+------------------
+
+Once we finish with the set up of Vulcanexus environment we are ready to start with the *talker-listener* demo tutorial.
+In this demo both a ``talker`` and a ``listener`` nodes from the ``demo_nodes_cpp`` ROS 2 package are created: the talker node will publish a "hello world" message every second, while the listener node will listen to these messages.
+By sourcing Vulcanexus you will get access to the CLI tool ``fastdds``, together with the ROS 2 environment.
+This tool gives access to the `discovery tool <https://fast-dds.docs.eprosima.com/en/latest/fastddscli/cli/cli.html#discovery>`__, which can be used to launch a discovery server.
+This server will manage the discovery process for the nodes that connect to it.
+
+.. important::
+
+    Do not forget to source ROS 2 every time you open another session to have access to the ROS 2 environment and the CLI tool ``fastdds``.
+
+
+Setup Discovery Server
+^^^^^^^^^^^^^^^^^^^^^^
+Start by launching a discovery server with id 0, port 11811 (default port) and listening on all available interfaces.
+The role of the server is to re-distribute the clients (and servers) discovery information to their known clients (and servers).
+
+.. code-block:: bash
+
+    fastdds discovery --server-id 0
+
+
+Launch Talker Node
+^^^^^^^^^^^^^^^^^^^
+Execute the Talker demo to publish on the ``/chatter`` topic. When setting the ``ROS_DISCOVERY_SERVER`` environment variable you are indicating that ROS node should act as a client that connects to a discovery server to discover other nodes on the network.
+Use the argument ``--remap __node:=talker_discovery_server`` to change the node’s name for this tutorial.
+
+.. code-block:: bash
+
+    export ROS_DISCOVERY_SERVER=127.0.0.1:11811
+    ros2 run demo_nodes_cpp talker --ros-args --remap __node:=talker_discovery_server
+
+
+Launch Listener Node
+^^^^^^^^^^^^^^^^^^^^^
+Execute the Listener demo to listen to the ``/chatter`` topic.
+
+.. code-block:: bash
+
+    export ROS_DISCOVERY_SERVER=127.0.0.1:11811
+    ros2 run demo_nodes_cpp listener --ros-args --remap __node:=listener_discovery_server
+
+

docs/rst/tutorials/core/ros2_tutorials.rst

@@ -11,6 +11,7 @@ This section provides a collection of tutorials on the use and application of th
 .. toctree::
     :maxdepth: 1
 
+    discoveryserver/discoveryserver_tutorials
     security/security_tutorials
     qos/qos_tutorials
     deployment/deployment_tutorials