gistfile1.txt

---
-
  become: true
  become_user: root
  hosts: all
  remote_user: ubuntu
  tasks:
    - name: update apt list of files
      apt:
         update_cache: true

    - name: install packages apt-transport-https ca-certificates curl
      apt:
         state: present
         install_recommends: false
         name:
          - apt-transport-https
          - ca-certificates
          - curl

    - name: curl thing
      shell: curl -fsSL https://apt.dockerproject.org/gpg | sudo apt-key add -

    - name: apt-key thing
      shell: apt-key fingerprint 58118E89F3A912897C070ADBF76221572C52609D


    - name: add docker repository
      shell: add-apt-repository  "deb https://apt.dockerproject.org/repo/ ubuntu-$(lsb_release -cs)  main"


    - name: update apt list of files
      apt:
         update_cache: true


    - name: install docker engine
      apt:
         state: present
         install_recommends: false
         name: docker-engine

    - name: test if docker installed correct
      shell: docker run hello-world




...