How to install the semaphore UI for running ansible

This blogpost is about how to install the semaphore user-interface for running ansible. Ansible is an automation language for automating IT infrastructures. It consists of command-line executables (ansible, ansible-playbook for example) that can run a single task using a module (using the ansible executable), or can run multiple tasks using multiple modules in order to perform more complex setup requirements (using the ansible-playbook executable). The downside of running IT tasks via the command-line is that there is no logging by default, unless someone decides to save the standard out to a file, which, if multiple people start doing that by hand will probably lead to a huge collection of text files which are hard to navigate. Also, when tasks are run via a common place, it’s an all or nothing situation: everybody has access to all the scripts, or to nothing.