ROS Docker Setup

Welcome to the Setup Guide for ROS in Docker.

Install Docker

• Create an account on DockerHub
• Follow instructions here to install docker for your Operating System.

Commands Specific to the Watch One, Do One, Teach One Project

One Time Setup

• Download the Dockerfile located here

• Navigate to the location where the Dockerfile is saved on your local machine and build the docker using:
  sudo docker build -t ros:melodic-desktop-full .

• Test if the docker was built using:
  sudo docker images
  If the docker was built, the output of this command would look like this

• Obtain the hostname for your system by running: hostnamectl. ( Hostname can be localhost too)

• Pull the wodoto repository in your local machine if you have not done so already.

• Spin up a container with the wodoto repository and the sound drivers mounted using the command (Replace path-to-repository and hostname appropriately):
  sudo docker run -it -v ~/.ssh:/root/.ssh -v /dev/snd:/dev/snd --privileged -v <path-to-wodoto-repository>:/root/catkin_ws --network host --env ROS_MASTER_URI=http://<hostname>:11311 --name ros_sound ros:melodic-desktop-full

• Add the following lines to your ~/.bash_profile file on your local machine replacing path-to-repository and hostname appropriately. Then source it by running:
  source ~/.bash_profile

• Install pip inside the container by following these instructions.

• Install vim inside the container by following these instructions.

Commands to Start and Test the ROS Docker for the First Time

• Run the ROS Docker Container created in the previous step by:
  sudo docker start ros
docker exec -it ros bash
  After running this, we would have entered inside the container, and the prompt will change to root@<hostname>:/#

• Inside the container source the setup.sh file by running:
  source /opt/ros/melodic/setup.sh

• Check if the catkin_ws is present inside the root directory inside the container.

• The code files should be present inside root/catkin_ws/ and the ROS packages should be present inside root/catkin_ws/src

• Run catkin_make inside root/catkin_ws. After catkin_make, check if build and devel directories are created inside the catkin_ws. Then run:
  source devel/setup.bash

• Run the following series of commands to test if we have a running ROS installation and can publish on a topic from within the container.
  roscore &
:
rostopic pub -r 1 /test std_msgs/String "test" &
:
  These commands mean that we first run roscore in the background, and publish a test message on the /test topic and send that process to the background.

• In order to check if the message was published on the topic run:
  rostopic list
  The topic /test should appear on the list.

• To verify if the test message is being published on the /test topic run:
  rostopic echo /test

Instructions for using the same container every time and running code

• List all the available containers using the command (The first 3 characters of the container ID or the name of the container listed in the last column can be used as the container_name):
  docker ps

• If there is a container found, it means that there is a container available and it is running. In order to enter that particular container use the command:
  docker exec -it ros bash

• If there is no container found after running docker ps, run docker ps -a. If there is a container found, it means that the container exists but is not running. In order to enter into the container run:
  docker start ros
docker exec -it ros bash
  The prompt will change to root@<hostname>:/# once we are inside the container.

• Once inside the container, source the setup.bash file using:
  source /opt/ros/melodic/setup.bash and inside the catkin_ws run source devel/setup.bash.

• In order to run ROS nodes, first run roscore & and send it to the background by running :. To spin up the required node, use the appropriate rosrun or roslaunch command as we do on the robot.

Shortcuts for Working with the Docker

Some aliases have been added on the .bash_profile file, to make working with this particular docker easier. To refer to what each alias does, see here

They are described here:

• build_ros_docker - build the ROS docker (one-time)
• run_docker - run the docker with the code mounted to create a container (one-time)
• list_images - list docker images (one-time)
• list_container - list running containers
• list_all_container - list all running as well as stopped containers
• exec_docker - execute a running container

General ROS Docker Commands

One Time Setup

• Pull the ROS docker image by running (one time setup):
  docker pull ros

• In your local machine clone the repository using the command:
  git clone <repository https: path>

• Spin up a container with the git repository mounted using the command:
  docker run -v <path_to_repository_in_your_local_machine>:/code/ -it ros

Instructions for using the same container every time

• Inside the container run roscore

• On a new terminal, list all the available containers using the command (The first 3 characters of the container ID or the name of the container listed in the last column can be used as the container_name):
  docker ps

• If there is a container found, it means that there is a container available and it is running. In order to enter that particular container use the command:
  docker exec -it <container_name> bash

• If there is no container found after running docker ps, run docker ps -a. If there is a container found, it means that the container exists but is not running. In order to enter into the container run:
  docker start <container_name>
docker exec -it <container_name> bash This will start an additional bash session in the same container.

• Once inside the container, source the setup.bash file using:
  source /opt/ros/melodic/setup.bash and inside the catkin_ws run source devel/setup.bash.

• To test if the instance is connected to the same ros-master run:
  rostopic list

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