Ansible blue-green deployment

Blue-green deployment for web applications with Ansible.

See Martin Fowler's BlueGreenDeployment post for insights.

This role will check whether blue or green should be deployed next and set the appropriate color in deploy_color.

The role uses the last author commit date in blue and green directories, and sets the deploy color to the directory having the oldest checkout.

This role only solves part of the problem: guessing which one of blue/green needs to be deployed. The rest (deploying, swapping colors at the loadbalancer, ...) is left to you.

Requirements

While there are no requirements for this role, your web application deployment role should be changed to use deploy in a directory specified by a variable (see Example below).

Role Variables

Required variables

• blue_green_directories: dict containing blue and green application directories below blue and breen keys

Optional variables

• verbose: will display variables set in role; primarily for command line usage

Variables set in role

• blue_green_color: which color has been selected for deploy
• blue_green_color_directory: in which directory the application can be deployed
• blue_green_color_parent_directory: in which directory the application can be checked out by the git module

Dependencies

None

Example

roles: - { role: ansible-blue-green, blue_green_directories: { blue: "/srv/www_blue/webapp", green: "/srv/www_green/webapp" } } - { role: my-webapp, my_webapp_home: "{{ blue_green_color_parent_directory }}", when: blue_green_color is defined }

Caveats

The color is determined upon commiter date. This information might be erroneous !

License

BSD

Author Information

@leucos