Ansible Playbook for seamless deployment with Docker.

Seamless web deployment with 1 loadbalancer and 3 application servers

---
- hosts: app_server_1
  user: ubuntu
  sudo: true
  roles:
  - docker_rails_app_build


- hosts: app_loadbalancer
  user: ubuntu
  sudo: true
  tasks:
    - name: take app_1 out of balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="server {{app_server_1}}\:8080\;" replace='# server {{app_server_1}}:8080;' backup=false

    - name: restart nginx
      shell: service nginx restart


- hosts: app_server_1
  user: ubuntu
  sudo: true
  roles:
  - docker_rails_app_run_prod
  - docker_rails_app_push


- hosts: app_loadbalancer
  user: ubuntu
  sudo: true
  tasks:
    - name: take app_1 back to balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="\# server {{app_server_1}}\:8080\;" replace='server {{app_server_1}}:8080;' backup=false

    - name: take app_2 out of balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="server {{app_server_2}}\:8080\;" replace='# server {{app_server_2}}:8080;' backup=false

    - name: restart nginx
      shell: service nginx restart


- hosts: app_server_2
  user: ubuntu
  sudo: true
  roles:
  - docker_rails_app_run_prod


- hosts: app_loadbalancer
  user: ubuntu
  sudo: true
  tasks:
    - name: wait a minute until Docker container is up and running
      pause: minutes=1

    - name: take app_2 back to balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="\# server {{app_server_2}}\:8080\;" replace='server {{app_server_2}}:8080;' backup=false

    - name: take app_3 out of balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="server {{app_server_3}}\:8080\;" replace='# server {{app_server_3}}:8080;' backup=false

    - name: restart nginx
      shell: service nginx restart


- hosts: app_server_3
  user: ubuntu
  sudo: true
  roles:
  - docker_rails_app_run_prod


- hosts: app_loadbalancer
  user: ubuntu
  sudo: true
  tasks:
    - name: wait a minute until Docker container is up and running
      pause: minutes=1

    - name: take app_3 back to balancing
      replace: dest=/etc/nginx/conf.d/default.conf regexp="\# server {{app_server_3}}\:8080\;" replace='server {{app_server_3}}:8080;' backup=false

    - name: restart nginx
      shell: service nginx restart