Adding Dependencies

How to Add Dependencies

There are different ways that dependencies should be added depending on whether the dependecies are ROS packages or Ubuntu package installed with apt.

Temporarily installing a ROS package dependency

Sometimes, you might want to temporarily install a ROS package to test it out before making the dependency permanent. To do this, simply start a docker container then use apt-get install to install the package.

You will need to change the name of the ROS package to match the naming scheme of ROS packages in the apt repository. The involves replacing all the underscores in the ROS package name with hyphens and add the prefix ros-kinetic (or ros-melodic if you're using melodic). For example, if you wanted to install the ROS package move_base, you would use this command:

apt-get install ros-kinetic-move-base

Note that packages you install with apt while a docker container is running will not remain installed after you stop and start the container again. If you decide that the ROS package should be installed permanently, follow the instructions below.

Dependency is a ROS package

If the dependency is a ROS package, it should be added to a package.xml for one of our packages. For example, our package spear_rover depends on the ROS robot_localization package. Therefore, we have added the following lines to spear_rover/package.xml:

  <build_depend>robot_localization</build_depend>
  <exec_depend>robot_localization</exec_depend>

Depending on whether the dependency is need at compile time, run time, or both, you may need to add it as a build_depend and/or an exec_depend. See this documentation for details about the differences between build_depend, exec_depend, and other types of ROS dependencies.

Dependency is not a ROS package but can be installed using apt

In this case, add the package to spear-env.Dockerfile as part of the apt-get install command. You will need to rebuild the spear-env image in order for the changes to take effect.

At present, you will also have to add the package to Vagrantfile to ensure it is installed within the VMs. This should change in the future, though.