1. Create a Ubuntu VM (it does not need a floating IP)
2. Connect to your VM

3. curl -L https://packages.gitlab.com/install/repositories/runner/gitlab-runner/script.deb.sh |\
   sudo bash

4. sudo apt-get install gitlab-runner

Source

1. sudo apt-get update

2. sudo apt-get install \
       apt-transport-https \
       ca-certificates \
       curl \
       software-properties-common

3. curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - 

4. sudo add-apt-repository \
      "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
      $(lsb_release -cs) \
      stable"

5. sudo apt-get update

6. sudo apt-get install docker-ce

7. check your installaton with:

   1. sudo docker run hello-world

Source

1. Get your project specific runner token (https://git.computational.bio.uni-giessen.de/<YourTeam>/<YourProject>/settings/ci_cd)
2. sudo gitlab-runner register (it will ask you for url, token, executor, etc. )