====== Installing ROS Melodic & ROS Dashing inside a Ubuntu Bionic chroot ======

  * Install Ubuntu inside a chroot. Follow guide from [[tutorials:ubuntu_bionic_chroot|here]]
  * Fix /etc/resolv.conf

  nameserver 8.8.8.8

  * Fix /etc/hosts. On the second line put the name of your hostname instead of 'shirka'.

  127.0.0.1	localhost
  127.0.1.1	shirka

  * Add all ubuntu repositories. Edit file /etc/apt/sources.list:

  deb http://mirrors.ucr.ac.cr/ubuntu bionic main universe restricted multiverse
  deb http://mirrors.ucr.ac.cr/ubuntu bionic-updates main universe restricted multiverse
  deb http://mirrors.ucr.ac.cr/ubuntu bionic-backports main restricted multiverse

  * Update repos

  $ apt-get update

  * Install the following packages:

  $ apt-get install sudo mc nano curl lsb-release gnupg2 apt-utils bash-completion locales

  * Add a new user in the chroot

  $ adduser user

  * Add your new user to sudo group

  $ adduser user sudo

  * Fix sudo error with visudo:

  $ visudo

  %sudo   ALL=(ALL:ALL) NOPASSWD:ALL

  * From now on, use your new user for the following steps:

  $ su user

  * Follow guide for ROS Melodic from ROS: [[http://wiki.ros.org/melodic/Installation/Ubuntu]]
  * Follow guide for ROS Dashing from ROS: [[https://index.ros.org/doc/ros2/Installation/Dashing/Linux-Install-Debians/]]

===== Creating ROS Melodic Workspace =====

Since ROS Hydro (ROS 1), ROS use [[wiki.ros.org/catkin/workspaces|Catkin]] for building all packages. The following links shows the basic steps for creating a Catkin Workspace.

  * [[http://wiki.ros.org/catkin/Tutorials/create_a_workspace|Create a workspace]]

After creating the workspace, build a basic package for testing purposes.

  * [[http://wiki.ros.org/catkin/Tutorials/CreatingPackage|Create a ROS package]]
  * [[http://wiki.ros.org/ROS/Tutorials/WritingPublisherSubscriber%28python%29|Writing a simple node in Python]]
  * [[http://wiki.ros.org/ROS/Tutorials/ExaminingPublisherSubscriber|Running the simple node]]

===== Creating ROS Dashing Workspace =====

Since ROS Crystal (ROS 2) to newer versions, ROS use [[https://colcon.readthedocs.io/en/released/|Colcon]] for building all packages. This guide shows the basic steps for creating a Colcon Workspace.

  * Source ROS 2 configuration

  $ source /opt/ros/dashing/setup.bash

  * Install colcon

  $ sudo apt install python3-colcon-common-extensions

  * Create workspace for ROS 2

  $ mkdir -p ~/ros2_ws/src

  * Move to the new workspace and build it

  $ cd ~/ros2_ws
  $ colcon build

  * Source workspace configuration

  $ source ~/ros2_ws/install/local_setup.bash && source ~/ros2_ws/install/setup.bash

After creating the workspace, lets build some examples packages for ROS 2.

  * Clone ROS 2 examples package repository in our workspace

  $ cd ~/ros2_ws/src
  $ git clone git clone https://github.com/ros2/examples
  $ git checkout $ROS_DISTRO

  * Build examples package

  $ cd ~/ros2_ws
  $ colcon build --symlink-install

  * Test builded package. Remember to run each command on different terminals and source ROS 2 configuration on each terminal.

  $ ros2 run examples_rclcpp_minimal_subscriber subscriber_member_function
  $ ros2 run examples_rclcpp_minimal_publisher publisher_member_function