Installing ROS Indigo with Gazebo 7 (or later) on Ubuntu 14.04

This tutorial will cover the easiest way to update the existing Gazebo version which comes with ROS Indigo (Gazebo 2) to a later release of Gazebo. Gazebo 2 is severely outdated and it's always better to use a newer version of the software.

To begin, let's first install ROS. If you already have ROS installed, you can skip this part and move on to the next part. If you want to do something else, check this detailed documentation for more details.

Ubuntu Installation of ROS Indigo

1. Configure your Ubuntu repositories
   Configure your Ubuntu repositories to allow "restricted", "universe", and "multiverse". You can follow the Ubuntu guide for instructions on doing this.
2. Setup your sources.list
   Setup your computer to accept software from packages.ros.org. ROS Indigo ONLY supports Saucy (13.10) and Trusty (14.04) for debian packages.
   

   sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

3. Set up your keys
   

   sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net --recv-key 0xB01FA116

4. Installation
   First make sure that your Debian package index is up-to-date
   

   sudo apt-get update

   Desktop-Full Install
   

   sudo apt-get install ros-indigo-desktop-full

5. Initialize rosdep
   Before you can use ROS, you will need to initialize rosdep. rosdep enables you to easily install system dependencies for source you want to compile and is required to run some core components in ROS.
   

   sudo rosdep init
   rosdep update

6. Environment setup
   It's convenient if the ROS environment variables are automatically added to your bash session every time a new shell is launched:
   

   echo "source /opt/ros/indigo/setup.bash" >> ~/.bashrc
   source ~/.bashrc

7. Getting rosinstall

   sudo apt-get install python-rosinstall

Updating to Gazebo 7

1. Removing Gazebo 2
   

   sudo apt-get remove gazebo2

   This might leave some unmet dependecies. But do not worry. It will be solved automatically.
2. Installing required packages of Gazebo 7
   

   sudo apt-get install ros-indigo-gazebo7-ros-pkgs ros-indigo-gazebo7-ros-control

   Even after installing this, there might be unmet dependencies. Just restart the terminal or source the ROS installation folder.

Congratulations! You have successfully changed the Gazebo version of your ROS distribution.