Conditionals

Overview

Conditionals are used to control the execution of tasks or playbooks based on specific conditions. They enable us to make our automation responsive to the state of a managed node, the value of a variable, or other factors. Ansible supports conditional statements using the when keyword, and it’s a powerful tool for creating flexible and adaptive automation workflows.

Working with conditionals

Conditionals are useful in a couple of scenarios. Let’s imagine that we’re responsible for managing a fleet of servers in a large data center, and we need to automate the deployment of a critical software update. However, the update is complex and resource-intensive, so we want to only apply it to a specific subset of servers based on various conditions. We can use conditionals for this kind of scenario.

There are various keywords used to enforce conditions in Ansible, such as:

• The when statement
• The failed_when statement
• The changed_when statement

The when statement

The when statement is used to specify a condition under which a task should be executed. If the condition evaluates to true, the task is executed; otherwise, it is skipped.

As shown below, a relevant example is ensuring the creation of symbolic links between NGINX site ...