The conditional control structure

Conditional control structures allow Ansible to follow an alternate path, skip a task, or select a specific file to import based on certain conditions. In a generic programming language, this is done with the help of if-then, else if, else, case statements. Ansible does this using the "when" statement. Some example conditions are:

• Whether a certain variable is defined
• Whether an earlier command sequence is successful
• Whether the task has run before
• Whether a platform on a target node matches the supported platforms
• Whether a certain file exists

The when statements

We have already used the when statement to extract the WordPress archive based on the result of another command, which is:

- name: download wordpress
    register: wp_download
- name: extract wordpress
    when: wp_download.rc == 0

This would be vaguely equivalent to writing a shell snippet, as follows:

DOWNLOAD_WORDPRESS
var=`echo $?
if [$var -eq 0]
then
    EXTRACT_WORDPRESS()
fi

In addition...