Let's go ahead and start deploying the application to understand how blue/green deployment works, by performing the following steps:
- We will create a new version of the web application that uses the nginx web server, as well as creating a definition file to deploy the nginx web server on our Mesos cluster using Marathon.
- We should focus on the following two new labels used for managing the blue/green deployment technique:
- HAPROXY_DEPLOYMENT_GROUP: This label uniquely identifies a pair of apps belonging to a blue/green deployment, and will be used as the app name in the HAProxy configuration.
- HAPROXY_DEPLOYMENT_ALT_PORT: An alternate service port is required because Marathon requires service ports to be unique across all apps.
- Then, we will install Python version 3, as required by zdd.py, Git, and our other dependencies...