synchronize treats ports on localhost as local connections

SUMMARY

When port forwarding a remote SSH server to a local port and using that local port in Ansible, synchronize module wrongfully treats it as a local connection and does not perform the transfer over SSH connection.

ISSUE TYPE

Bug Report

COMPONENT NAME

synchronize

ANSIBLE VERSION

ansible [core 2.15.9]
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/jack/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /home/jack/.ansible/collections:/usr/share/ansible/collections
  executable location = /usr/bin/ansible
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True

COLLECTION VERSION

# /usr/lib/python3/dist-packages/ansible_collections
Collection    Version
------------- -------
ansible.posix 1.5.4

CONFIGURATION

CONFIG_FILE() = /etc/ansible/ansible.cfg
EDITOR(env: EDITOR) = subl -w

OS / ENVIRONMENT

Running Ubuntu 22.04 on both the controller node and the remote.

STEPS TO REPRODUCE

In real environment, I forward the SSH port of a different machine in the network that the machine I ssh into is but this example should highlight the issue as well and is simple to create a reproduction for.

Create a file playbook.yaml with the following contents:

---
- hosts: all
tasks:
- ansible.posix.synchronize:
    src: folder
    dest: /tmp/folder

Create a file inventory.yaml with the following contents (replace <user> with the user to connect with):
```
all:
hosts:
127.0.0.1:
  ansible_connection: ssh
  ansible_port: 1234
  ansible_user: <user>
```
Create a folder named folder.
Create a file named file in the folder folder.
Run ssh <user>@<host> -L 127.0.0.1:1234:127.0.0.1:22 in another terminal window.
Run ansible-playbook playbook.yaml -i inventory.yaml.
Validate that the rsync only worked locally by checking that /tmp/folder was created on the controller node rather than the remote node.

For comparison to how it should actually work, you can change the inventory.yaml file to:

all:
  hosts:
    <host>:
      ansible_connection: ssh
      ansible_port: 22
      ansible_user: <user>

EXPECTED RESULTS

I expected the local folder to get properly synced to the remote folder.

ACTUAL RESULTS

The local folder gets synced to the local folder.

Here's the actual output: https://gist.github.com/Jackenmen/20de4a647cfb607f5a7d17232a01a998/raw/c57f02ec315fcf678db67a7034c5b7a9b751deb2/actual_result_1234.log

and for comparison, here's the expected output that I get when using <user>@<host>:22 directly: https://gist.github.com/Jackenmen/20de4a647cfb607f5a7d17232a01a998/raw/c57f02ec315fcf678db67a7034c5b7a9b751deb2/expected_result.log

ansible-collections / ansible.posix