systemd_service - Add the machine parameter (#82958)

[jimmy-lt]

Fixes #82958

systemctl's --machine option execute the operation in the context of a local user session or a local container.

This provides a failsafe way to run systemd on behalf of another user than setting the XDG_RUNTIME_DIR variable.

SUMMARY

When trying to run systemd as another user, the following is advised:

- name: Run a user service when XDG_RUNTIME_DIR is not set on remote login
  ansible.builtin.systemd_service:
    name: myservice
    state: started
    scope: user
  environment:
    XDG_RUNTIME_DIR: "/run/user/{{ myuid }}"

However, this may not always work and can fail in various ways, typically:

Failed to connect to bus: Operation not permitted

Since systemd 248, the --machine option is available to to open a connection to the session bus of a specific user.

ISSUE TYPE

• Feature Pull Request

ADDITIONAL INFORMATION

- name: Run from within a specific user session
  ansible.builtin.systemd_service:
    name: myservice
    state: started
    scope: user
    machine: myuser@.host

"invocation": {
    "module_args": {
        "daemon_reexec": false,
        "daemon_reload": false,
        "enabled": true,
        "force": null,
        "machine": "myuser@.host",
        "masked": null,
        "name": "myservice",
        "no_block": false,
        "scope": "user",
        "state": "started"
    }
}

[ansibot]

The test ansible-test sanity --test pep8 [explain] failed with 1 error:

lib/ansible/modules/systemd_service.py:88:161: E501: line too long (177 > 160 characters)

click here for bot help