Add role for installing Docker tools

playbooks/roles/docker-tools/defaults/main.yml

+cache_valid_time: 3600
+
+docker_tools_deps_deb_pkgs:
+    - apt-transport-https
+    - ca-certificates
+    - python-pip
+
+docker_apt_keyserver: "hkp://ha.pool.sks-keyservers.net:80"
+docker_apt_key_id: "58118E89F3A912897C070ADBF76221572C52609D"
+docker_repo: "deb https://apt.dockerproject.org/repo ubuntu-xenial main"
+
+docker_group: "docker"
+docker_users: []

playbooks/roles/docker-tools/tasks/main.yml

+# Install docker-engine and docker-compose
+# Add users to docker group
+---
+- name: add docker group
+  group:
+    name: "{{ docker_group }}"
+
+- name: add users to docker group
+  user:
+    name: "{{ item }}"
+    groups: "{{ docker_group }}"
+    append: yes
+  with_items: "{{ docker_users }}"
+
+- name: install package dependencies
+  apt:
+    name: "{{ docker_tools_deps_deb_pkgs }}"
+    update_cache: yes
+    cache_valid_time: "{{ cache_valid_time }}"
+
+- name: add docker apt key
+  apt_key:
+    keyserver: "{{ docker_apt_keyserver }}"
+    id: "{{ docker_apt_key_id }}"
+
+- name: add docker repo
+  apt_repository:
+    repo: "{{ docker_repo }}"
+
+- name: install docker-engine
+  apt:
+    name: "docker-engine"
+    update_cache: yes
+    cache_valid_time: "{{ cache_valid_time }}"
+
+- name: start docker service
+  service:
+    name: docker
+    enabled: yes
+    state: started
+
+- name: install docker-compose
+  pip:
+    name: "docker-compose"