dockerfile_scripts

Prepare your Dockerfile and scripts

• You will need to create three files: Dockerfile, ros_entrypoint.sh, and run_my_system.bash. *First, create a directory to keep them in:

mkdir ~/vorc_docker; cd ~/vorc_docker

Prepare the Dockerfile

• Run gedit Dockerfile and copy the following text into it:

# This is an auto generated Dockerfile for ros:ros-base
# generated from docker_images/create_ros_image.Dockerfile.em
FROM ros:melodic-ros-core-bionic

# install ros packages
RUN apt-get update && apt-get install -y \
    ros-melodic-ros-base=1.4.1-0* \
&& rm -rf /var/lib/apt/lists/*

# Copy over script to Docker container
COPY ./run_my_system.bash /

# Use your ros_entrypoint
COPY ./ros_entrypoint.sh /

Prepare ros_entrypoint.sh

• Run gedit ros_entrypoint.sh and copy the following text into the file:

#!/bin/bash
set -e

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

/run_my_system.bash

Then run chmod +x ros_entrypoint.sh to make it executable.

Prepare run_my_system.sh

• Run gedit run_my_system.sh and 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 /vorc/thrusters/left_thrust_cmd std_msgs/Float32 -r ${RATE} -- ${CMD} &
rostopic pub /vorc/thrusters/right_thrust_cmd std_msgs/Float32 -r ${RATE} -- ${CMD}

Then run chmod +x run_my_system.bash to make it executable.