Including this role makes it impossible to use --tags to select certain tasks/roles

[Ramblurr]

So this is a strange one.

I have a playbook for managing a server. The playbook includes baseline host setup (ntp, sshd config, etc), backup setup (via this role), and finally workload setup that manages the services running on the host.

When I want to target a specific set of roles/tasks using the --tags option, I receive the following error from this role. Notably this only happens when I've specified a tag that doesn't include the borgbackup role.

$ ansible-playbook services.yml --tags workload-setup

... snip...

TASK [m3nu.ansible_role_borgbackup : Run OS-specific tasks] ****************************************************
Tuesday 24 August 2021  21:54:14 +0200 (0:00:21.284)       0:00:21.284 ******** 
fatal: [redactedhostname]: FAILED! => 
  msg: No file was found when using first_found. Use errors='ignore' to allow this task to be skipped if no files are found

Here is a simple playbook to repro this:

---
- name: backup config
  hosts: example
  become: true
  tags: [backup]
  roles:
    - role: m3nu.ansible_role_borgbackup

- name: workload
 hosts: example
  become: true
  tags: [workload]
  tasks:
    - debug:
        msg: setup app services

Running this with ansible-playbook test.yml will work fine, but running it with ansible-playbook test.yml --tags workload results in the error above.

[egdoc]

The role loads system-specific variables from the "var" directory; those variables are contained in files named after the os family/distribution as they are reported by the fact gathering module:

# tasks/01_install.yml
- name: Include OS-specific variables
    include_vars: "{{ item }}"
    with_first_found:
      - "{{ ansible_distribution }}-{{ ansible_distribution_major_version }}.yml"
      - "{{ ansible_os_family }}-{{ ansible_distribution_major_version }}.yml"
      - "{{ ansible_distribution }}.yml"
      - "{{ ansible_os_family }}.yml"
      - "{{ ansible_lsb.id }}.yml"

Since you specify a tag at the playbook level (e.g "workload"), when you execute the playbook with -t workload the "gather_facts" step is not executed, therefore the role doesn't find a file to load. See https://github.com/ansible/ansible/issues/57529.

[m3nu]

This needs the tag always, right?