HAProxy blue-green
Backend-switching based blue-green deployements.
This role will let you swap haproxy backends depending on the deployed color.
When used, it will create two backends: blue and green. You call this role with blue_green_color set to blue or green, and it will set the current color to blue_green_color.
It works by setting the inactive color backend to disabled.
The blue-green deployement process roughly follows this pattern:
- check which color is the oldest (and thus, can be deployed)
- deploy application to the corresponding color target (a directory for instance)
- point loadbalancers to the new color
Requirements
Any pre-requisites that may not be covered by the ansible itself or the role should be mentioned here. For instance, if the role uses the EC2 module, it may be a good idea to mention in this section that the boto package is required.
Role Variables
haproxy_blue_green_front_name: HAproxy frontend entry name to createhaproxy_blue_green_loadbalancers: Group name of loadbalancers to configurehaproxy_blue_green_backend_group: Group name of backend to add in the backend
Usage
The role is supposed to be used this way from a playbook:
- { role: leucos.haproxy-blue-green,
haproxy_blue_green_front_name: 'myfront',
haproxy_blue_green_loadbalancers: 'lb',
haproxy_blue_green_backend_group: 'www',
when: blue_green_color is defined }
blue_green_color can be set earlier in the playbook using leucos.blue-green role, which tries to guess which color is the oldest (and thus, can be redeployed).
Dependencies
This role depends on:
- leucos.haproxy-multi for HAProxy configuration (using multiple configuration file)
- leucos.blue-green for blue-green color guessing
License
MIT