catchingerrors-playbook.yaml

---
- name: A playbook for demonstrating error handling techniques
  hosts: planetexpress
  gather_facts: yes

  vars:
          apps_to_install: [apache2, vsftpd]

  tasks:
          - name: PRECHECK PHASE
            block:
                    - name: Ensure platforms we logged into are all Debian
                      fail:
                              msg: "Ansible has detected this host is not supported"
                      when: ansible_os_family != "Debian"

            rescue:
                    - name: PRECHECK PHASE - FAILED
                      fail:
                              msg: "PRECHECK PHASE - FAILED! Nothing to rollback. Exiting..."


          - name: MAINTENANCE PHASE
            block:
                    - name: Install services to our remate hosts
                      apt:
                              state: present
                              name: "{{ apps_to_install }}"
                      become: yes

                    - name: Turn up the service
                      service:
                              state: started
                              name: "{{ item }}"
                      loop: "{{ apps_to_install }}"
                      become: yes
                      # with_item   <--- old way to do a loop

            rescue:
                    - name: MAINTENANCE PHASE - FAILED - Rollback services on remote hosts
                      apt:
                              state: absent
                              name: "{{ apps_to_install }}"
                      become: yes

                    - name: MAINTENANCE PHASE FAILED - ROLL BACK COMPLETE... EXITING
                      fail:
                              msg: "FAILED! Rollback complete. Exiting..."

          - name: POSTCHECK PHASE
            block:
                    - name: populate service facts
                      service_facts:

                    - name: show the services running
                      debug:
                              var: ansible_facts.services # this was auto created by service_facts

                    - name: ensure our new services are installed
                      fail:
                              msg: "Ansible has detected not all services have installed properly"
                      when: ansible_facts.services.get(item).state != "running"
                      loop: "{{ apps_to_install }}"

            rescue:
                    - name: POSTCHECK - FAILED - Rollback services on remote hosts
                      apt:
                              state: absent
                              name: "{{ apps_to_install }}"
                      become: yes

                    - name: POSTCHECK PHASE FAILED - ROLL BACK COMPLETE... EXITING
                      fail:
                              msg: "FAILED! Rollback complete. Exiting..."

        ## in a real deployment you might consider an ALWAYS section to provide the results
        ## of how the playbook ran
        # always:
        #      - name: EXAMPLE - Email your team the results of the playbook
        #        mail:   # mail module is used to send SMTP (email)
        #           host:
        #           port:
        #           password:
        #           username:
        #           subject:
        #           body: send an email with results via the mail module