Ansible react on unreachable / failed hosts

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1

I am administering a heterogeneous environment with a lot of stakeholders. It would be crucial to react on unreachable and failed hosts differently. So far my solution is:

`

  • hosts: all:localhost
    tasks:

If fact gathering fails - > host unreachable

  • set_fact:
    unreachable_hosts: “{{ ansible_play_hosts_all | difference(ansible_play_hosts) }}”
    reachable_hosts: “{{ ansible_play_hosts }}”
    delegate_to: localhost
    run_once: True

  • import_role: …

if the role has failed

  • set_fact:
    failed_deployment: “{{ reachable_hosts | difference(ansible_play_hosts) }}”
    delegate_to: localhost
    run_once: True

Here could be the notification modules

  • debug:
    msg: “unreachable: {{ unreachable_hosts }}, failed: {{ failed_connection }}”
    delegate_to: localhost
    run_once: True

`

It seems a little clumsy to me. Is there a way to check if a host is reachable with a module?
Is this the standard way of handling failed connections?

Thanks

2

It's possible to test the connection, register and use the result. For example

    - delegate_to: localhost
      command: ping -c1 "{{ inventory_hostname }}"
      register: result
      ignore_errors: true

Your solution is cleaner. I'd propose to create a group of reachable
hosts and structure the the playbook into more plays. For example

    - name: Create group of reachable hosts
      hosts: all
      gather_facts: true
      tasks:
        - add_host:
            name: '{{ item }}'
            groups: 'reachable'
          loop: "{{ ansible_play_hosts }}"
          run_once: true
        - set_fact:
            unreachable_hosts: "{{ ansible_play_hosts_all|
                                   difference(ansible_play_hosts) }}"
          delegate_to: localhost
          delegate_facts: true
          run_once: true

    - name: Manage reachable hosts
      hosts: reachable
      gather_facts: true
      tasks:
        - debug:
            var: inventory_hostname

    - name: Manage unreachable hosts
      hosts: localhost
      gather_facts: true
      tasks:
        - debug:
            var: item
          loop: "{{ unreachable_hosts }}"

Notes:

1) "gather_facts: true" in the first play is necessary to
   remove unreachable hosts from "ansible_play_hosts".

2) It's not necessary to delegate "add_hosts".

3) It's necessary "delegate_facts: true" to declare the variable
   "unreachable_hosts" in the "hostvars['localhost']".

Cheers,

  -vlado