To run this, assuming you have ansible installed - first change the IP address to match the primary interface on your server in install_docker.yml on the line (I'm sure there's a more 'ansible' way to get the IP...) :
shell: docker swarm init --advertise-addr=192.168.1.34
And change the hostname ("Host(traefik.192.168.1.34.xip.io)") and password for the traefik dashboard in traefik.yml (there is a little explanation of how to do it in the file). Then run the playbook against the same IP :
ansible-playbook install_docker.yml -i 192.168.1.34,(Note the trailing ,)