tutorials vrx_docker_interactive

Option 1: Pull the ROS Noetic Docker image and manually run desired commands to setup the system

• Run docker run --name my_container -it ros:noetic-ros-base. This will pull the ros:noetic-ros-base image from DockerHub and create a container of that image called my_container. -it` is added so that when this is complete, it starts an interactive Bash session for you to run commands. This may take a few minutes to run.

• This Bash session is very barebones. It does not have a text editor yet, so we will install one now. From the created interactive Bash session, run apt-get update && apt-get install -y nano or replace nano with your text editor of choice.

• Use the text editor to edit ros_entrypoint.sh. Eg. nano /ros_entrypoint.sh. This is a script that is run immediately after your container has been built. Replace all the text with the following:

#!/bin/bash
set -e

# setup ros environment
source "/opt/ros/$ROS_DISTRO/setup.bash"

/run_my_system.bash

This will run the script run_my_system.bash.

• Create the run_my_system.bash script. nano /run_my_system.bash. Copy the following text into the file

#!/bin/bash

# Create ros master if not already started
rostopic list > /dev/null 2>&1
retVal=$?
if [ $retVal -ne 0 ]; then
    roscore &
    echo "Wait for 5s to allow rosmaster to start"
    sleep 5s
else
    echo "rosmaster already setup"
fi

# Send forward command
RATE=1
CMD=2
echo "Sending forward command"
rostopic pub /wamv/thrusters/left_thrust_cmd std_msgs/Float32 -r ${RATE} -- ${CMD} &
rostopic pub /wamv/thrusters/right_thrust_cmd std_msgs/Float32 -r ${RATE} -- ${CMD}

• Run chmod +x /run_my_system.bash to make it executable.

• Run /run_my_system.bash & to execute the script in the background. You should see the ros core service start up, and the output of the echo message, "Sending forward command data", from the script you just created.

• Hit enter to get back to a command prompt and run rostopic echo /wamv/thrusters/left_thrust_cmd to test that your script is publishing data as expected. You should receive /wamv/thrusters/left_thrust_cmd data (which is set to 2.0 in the script).

• Run exit to leave this container.

• Run docker ps -a to list all containers. You should see your container my_container.

• Copy the Container ID of my_container.

• Run docker commit -m "Start off ros-noetic-base, add run_my_system simple script" -a "<FULL NAME>" <Container_ID> <USERNAME>/<IMAGE_REPOSITORY_NAME>:<TAG>. Your username must match the username of your Dockerhub account. The image repository name is the repository name that the image will be saved to on Dockerhub. The tag and colon are optional (but highly recommended) to help you version your images. Example: docker commit -m "Start off ros-melodic-base, add run_my_system simple script" -a "Tyler Lum" a0e1e92cb6a5 tylerlum/vrx-competitor-example:v2.2019 or docker commit -m "Start off ros-melodic-base, add run_my_system simple script" -a "Tyler Lum" a0e1e92cb6a5 tylerlum/vrx-competitor-example

• Run docker login

• Run docker push <USERNAME>/<IMAGE_REPOSITORY_NAME>:<TAG> with the same information as the previous step. Eg. docker push tylerlum/vrx-competitor-example:v2.2019

• You should be able to log onto your Dockerhub account and see your new repository.

• Optional: If you want to keep your repository private, you can click on your repository, then click Settings, then Make Private. To ensure that your Docker image can be evaluated, you can click Collaborators and add the desired Docker ID. Exact details about submission and Docker ID are coming soon.