Reducing deployment downtime with Terraform

In Chapter 2, Provisioning Cloud Infrastructure with Terraform, we detailed the use of Terraform by looking at its commands and life cycle and put it into practice with an implementation in Azure.

One of the problems with Terraform is that, depending on the infrastructure changes that need to be implemented, Terraform may automatically destroy and rebuild certain resources.

To fully understand this behavior, let's look at the output of this following Terraform execution, which provisioned an Azure Web App in Azure and has been modified with a name change:

Figure 15.1 – Terraform downtime

Here, we can see that Terraform will destroy the web app and then rebuild it with the new name. Although destruction and reconstruction are done automatically, while Terraform is destroying and rebuilding the web app, the application will be inaccessible to users.

To solve this problem of downtime, we can...