ansible error: skipping: no hosts matched I've tried a few variations on running ansible locally as a test case:
nicholas $ 
nicholas $ ls
ansible.cfg  ansible.cfg.orig  first_playbook.yml  inventory.txt  playbook.yml
nicholas $ 
nicholas $ cat ansible.cfg
[defaults]
transport = local

nicholas $ 
nicholas $ cat playbook.yml 
---

- name: Network Getting Started First Playbook
  connection: network_cli
  gather_facts: false
  hosts: all
  tasks:

    - name: Get config for VyOS devices
      vyos_facts:
        gather_subset: all

    - name: Display the config
      debug:
        msg: &quot;The hostname is {{ ansible_net_hostname }} and the OS is {{ ansible_net_version }}&quot;

nicholas $ 
nicholas $ ansible --version
ansible 2.9.6
  config file = /home/nicholas/ansible/ansible.cfg
  configured module search path = ['/home/nicholas/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.8.2 (default, Jul 16 2020, 14:00:26) [GCC 9.3.0]
nicholas $ 
nicholas $ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04 LTS
Release:    20.04
Codename:   focal
nicholas $ 
nicholas $ ansible-playbook --connection=local  playbook.yml
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [Network Getting Started First Playbook] **************************************************************************************
skipping: no hosts matched

PLAY RECAP *************************************************************************************************************************

nicholas $ 

perhaps I need an additional configuration for the localhost loopback?
Although I can ping localhost as:
nicholas $ 
nicholas $ ansible localhost -m ping -u root
127.0.0.1 | SUCCESS =&gt; {
    &quot;ansible_facts&quot;: {
        &quot;discovered_interpreter_python&quot;: &quot;/usr/bin/python3&quot;
    },
    &quot;changed&quot;: false,
    &quot;ping&quot;: &quot;pong&quot;
}
nicholas $
The answer is in the warning you get:
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

When you use hosts: all in your playbook, localhost is not matched.
If you want to run the playbook on localhost, you can do one of the following:

Change your playbook to hosts: localhost.
Explicitly provide an inventory file that has localhost.

You can create an inventory file - inventory.yml with the contents:
all:
  hosts:
    localhost

and then pass this inventory file to ansible explicitly like this:
$ ansible-playbook --connection=local -i inventory.yml playbook.yml
You can find more information about inventory in the Ansible documentation.