.travis.yml

# NOTE: The build lifecycle on Travis.ci:
#
#   checkout git repository and cd into repo
#   install apt addons
#   cache components
#
#   before_install : install dependencies (Ubuntu packages or services)
#   install        : install/setup project
#   before_script  : setup script's environment
#   script         : run the build script
#   before_cache   : for cleaning up cache
#   after_           (can access $TRAVIS_TEST_RESULT env)
#     success      : e.g., build documentation or deploy to server
#     failure      : e.g., upload log files
#   before_deploy
#   deploy         : Deploy code to Heroku, Engine Yard, etc.
#   after_deploy
#   after_script

###########################################################
# Configuration
###########################################################
sudo: required
language:
  - generic
cache:
  - apt
services:
  - docker
env:
  global:
    - CI_SOURCE_PATH=$(pwd)
    - ROSINSTALL_FILE=$CI_SOURCE_PATH/dependencies.rosinstall
    - CATKIN_OPTIONS=$CI_SOURCE_PATH/catkin.options

before_install:
  # Docker is required to run Ubuntu 16.04.2 LTS (Xenial Xerus) and,
  # therefore, ROS Kinetic
  - docker pull ros:kinetic-ros-core

script:
  # Run the build test script in the docker container
  # docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
  #   run : run a command in the new container
  #     -v $(pwd):$(pwd) : mount the current directory in the container
  #     ros:kinetic-ros-base : is the image
  #     /bin/bash -c "source $(pwd)/.travis.sh" : the command to run in the container
  #       the -c flag tells bash to execute commands from the given string
  #         the source built-in command executes the script **in the current shell**
  - docker run -v $(pwd):$(pwd) ros:kinetic-ros-base /bin/bash -c "source $(pwd)/.travis.sh"