Managing exceptions

There are many cases where, for one reason or another, you want your playbook and roles to carry on in case one or more tasks fail. A typical example of this could be that you want to check whether software is installed or not. Let's look at the following example to install Java 11 if, and only if, Java 8 is not installed. In the roles/java/tasks/main.yaml file, we are going to enter the following code:

- name: Verify if Java8 is installed
  command: rpm -q java-1.8.0-openjdk
  args:
    warn: False
  register: java 
  ignore_errors: True 
  changed_when: java is failed 

- name: Ensure that Java11 is installed
  yum:
    name: java-11-openjdk
    state: present
  become: True
  when: java is failed

Before going forward with the other parts that are needed to execute this role, I'd like to spend a few words on the various parts of the role task list, since there...