The ROS GUI Server package is the component of the ROS GUI system which runs on the target robot. It includes a ros_gui_server_node which subscribes to an nav_msgs/Odometry topic, exposes Odometry, rviz visualization, and robot navigation through actionlib actions to the ROS GUI Client.
Setting up the ros_gui_server package in your ROS environment can get a bit involved, however I intented to give thorough enough explanations so that anyone familiar with ROS, or Linux in general could set this up easily.
The first few step are fairly standard, simply clone this repository in a catkin workspace on the host device (robot), run catkin_make to generate a new setup.bash, source it from the devel folder, and execute the command rosdep install ros_gui_server to gather all of the dependancies.
After you've downloaded and catkin_maked the ros_gui_server package, you'll also need to configure it's launch file, found at <your catkin workspace>/src/ros_gui_server/launch/server.launch.
This file launches the ros_gui_server node, as well as a robot_state_publisher, joint_state_publisher, and tf2_web_republisher node, while also including the launch files for the ros-bridge websocket and your navigation stack's move_base launch file.
As noted by the comments in the launch file, you'll need to specify which nav_msgs/Odometry topic you're publishing on for the server to subscribe to, an IP and Port for the rosbridge websocket (leave this default), and you'll also need to specify the package in which your move_base launch file resides. Where it says $(find husky_navigation) you can replace 'husky_navigation' with the name of your <robot_navigation> package.
After that, just make sure to include this launch file within any robot_bringup launch files you wish to run the ros_gui_server with.
In order a to serve the URDF and the GUI in the browser, its files need to be served via the http protocol. To accomplish this, we can set up an Apache2 webserver on the host device and make some modifications to it.
First, we need to download Apache to the host device:
sudo apt update
sudo apt install apache2
Then, we'll need to enable header modification:
sudo a2enmod headers
Next, we'll create a config for our new site, we can just copy the default one:
cd /etc/apache2/sites-available/
sudo cp 000-default.conf gui.conf
Then, we need to add our header modification mentioned previously, start by opening our newly created config file:
sudo nano gui.conf
Scroll down to near the end of the <VirtualHost> tag and add the following line into it:
Header set Access-Control-Allow-Origin '*'
The above line allows the URDF to be served to the client's browser without causing any security errors, after saving the gui.conf file, we'll need to disable the default site, enable our new one, and restart the apache server.
sudo a2dissite 000-default.conf
sudo a2ensite gui.conf
sudo service apache2 restart
Now that our apache server is properly configured, we need to copy the URDF (typically in a robot_description package) into the content directory for the site. To do this simply execute these commands, replacing <robot-description> with the path to your robot_description package.
sudo rm /var/www/html/index.html
sudo mkdir /var/www/html/urdf
sudo cp -r <robot_description>/ /var/www/html/urdf/
Next, we'll pull the ros_gui_client repository to also be served by our apache server.
sudo mkdir /var/www/html/gui
sudo chmod 777 /var/www/html/gui
git clone git@github.com:UGA-BSAIL/ros_gui_client.git /var/www/html/gui/
Then, we can reload the apache server to serve the new content, and our apache server config is complete!
sudo service apache2 reload
After that you should be all configured!
Please refer to the UGA-BSAIL/ros_gui_client repository README.md for more information on using the ros_gui_client froma browser.