for me

first change DockerFile to the following:


FROM dorowu/ubuntu-desktop-lxde-vnc:focal
LABEL maintainer="Unity Robotics <unity-robotics@unity3d.com>"

ENV DEBIAN_FRONTEND noninteractive ENV DEV_NAME=rosdev ENV ROS_DISTRO=galactic ENV GROUP_NAME=ros ENV WS_NAME=colcon_ws

RUN wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | apt-key add -

RUN echo "Set disable_coredump false" >> /etc/sudo.conf RUN apt-get update -q && \ apt-get upgrade -yq && \ apt-get install -yq \ wget \ curl \ git \ build-essential \ vim \ sudo \ gnupg2 \ lsb-release \ locales \ bash-completion \ tzdata \ gosu \ python3-argcomplete \ python3-pip \ && rm -rf /var/lib/apt/lists/*

Install the immutable components BEFORE we copy in build context stuff to keep the rebuild process manageable

RUN curl http://repo.ros2.org/repos.key | sudo apt-key add - RUN curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | apt-key add - && \ echo "deb [arch=$(dpkg --print-architecture)] http://packages.ros.org/ros2/ubuntu $(lsb_release -cs) main" > \ /etc/apt/sources.list.d/ros2-latest.list && \ apt-get update -q && \ apt-get install -y --no-install-recommends \ ros-${ROS_DISTRO}-desktop \ python3-rosdep \ python3-colcon-common-extensions \ python3-vcstool \ ros-galactic-navigation2 \ ros-galactic-nav2-bringup \ && rm -rf /var/lib/apt/lists/* && rm /etc/apt/sources.list.d/ros2-latest.list

RUN useradd --create-home --home-dir /home/${DEV_NAME} --shell /bin/bash --user-group --groups adm,sudo ${DEV_NAME} && \ echo "$DEV_NAME:$DEV_NAME" | chpasswd && \ echo "$DEV_NAME ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers COPY --chown=${DEV_NAME} colcon_ws /home/${DEV_NAME}/colcon_ws COPY ros2-setup.bash /bin/ros2-setup.bash

Doing a second fetch of sources & apt-get update here, because these ones depend on the state of the build context

in our repo

RUN curl http://repo.ros2.org/repos.key | sudo apt-key add - RUN curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | apt-key add - && \ echo "deb [arch=$(dpkg --print-architecture)] http://packages.ros.org/ros2/ubuntu $(lsb_release -cs) main" > \ /etc/apt/sources.list.d/ros2-latest.list && \ apt-get update -q && \ rosdep init && \ chmod +x /bin/ros2-setup.bash && \ gosu ${DEV_NAME} /bin/ros2-setup.bash && \ runuser -u ${DEV_NAME} ros2-setup.bash && \ rm /bin/ros2-setup.bash && \ rm -rf /var/lib/apt/lists/* && rm /etc/apt/sources.list.d/ros2-latest.list

RUN echo ". /opt/ros/${ROS_DISTRO}/setup.bash" >> /home/${DEV_NAME}/.bashrc && \ echo ". /home/${DEV_NAME}/${WS_NAME}/install/local_setup.bash" >> /home/${DEV_NAME}/.bashrc

ENV TURTLEBOT3_MODEL=waffle_pi

To bring up tb3 simulation example (from https://navigation.ros.org/tutorials/docs/navigation2_with_slam.html)

cd catkin_ws && source install/setup.bash && ros2 launch nav2_bringup tb3_simulation_launch.py slam:=True

Informs the environment that the default user is not root, but instead DEV_NAME

ENV USER ${DEV_NAME}


2. if encounter problem like " Failed to connect to raw.githubusercontent.com ", ensure your local network can visit https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc, otherwise your have to modify your local network, like hosts or VPN, for me, i use VPN and change hosts at docker build command:
`docker build --add-host=raw.githubusercontent.com:185.199.110.133 -t unity-robotic:nav2-slam-example ./`
change the host ip depends on your network.

Unity-Technologies / Robotics-Nav2-SLAM-Example

ERROR keyserver 'hkp://keyserver.ubuntu.com:80' #66