Rolling updates using Ansible

Continuous deployment is a method meant for frequent application deployment (together with CI/CD) and frequent updates of your application or website rather than you having to wait for scheduled downtime and deployment cycles. But you also need to ensure the application will be available during the update process. So far, you have learned that application high availability can be achieved using a load balancer. In this section, you will learn how to update the application on web servers without downtime.

Steps involved in an application update

Depending on your application’s type and the components involved, the update process may contain different steps and procedures. The following diagram shows the generic steps involved in the application update process, which is running behind a load balancer:

Figure 9.23 – Steps involved in an application update

It is possible to automate all such tasks using Ansible,...