Ansible says: "might be an issue with missing quotes" in wireguard.yml. [Ubuntu 18.04.2 LTS]

[johnnyutahh]

Ignorant Ansible user here, trying to install Wireguard simply to the localhost running Ubuntu 18.04.2 LTS. What am I missing?

root@node110 Sep 06 14:19:58 /root# ansible-galaxy install mina-alber.wireguard-ansible
- downloading role 'wireguard-ansible', owned by mina-alber
- downloading role from https://github.com/mina-alber/wireguard-ansible/archive/v1.1.0.tar.gz
- extracting mina-alber.wireguard-ansible to /root/.ansible/roles/mina-alber.wireguard-ansible
- mina-alber.wireguard-ansible (v1.1.0) was installed successfully
root@node110 Sep 06 14:20:03 /root# 

[...]

root@node110 Sep 06 14:28:59 /root/.../roles/mina-alber.wireguard-ansible# ansible-playbook -i hosts_inventory wireguard.yml
ERROR! the role 'wireguard-ansible' was not found in /root/.ansible/roles/mina-alber.wireguard-ansible/roles:/root/.ansible/roles:/root/.ansible/roles/mina-alber.wireguard-ansible

The error appears to have been in '/root/.ansible/roles/mina-alber.wireguard-ansible/wireguard.yml': line 6, column 7, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

  roles:
    - "{{role_name|default('wireguard-ansible')}}"
      ^ here
We could be wrong, but this one looks like it might be an issue with
missing quotes.  Always quote template expression brackets when they
start a value. For instance:

    with_items:
      - {{ foo }}

Should be written as:

    with_items:
      - "{{ foo }}"

root@node110 Sep 06 14:29:02 /root/.../roles/mina-alber.wireguard-ansible#
root@node110 Sep 06 14:34:22 /root/.../roles/mina-alber.wireguard-ansible# cat hosts_inventory 
[all]

# wireguard    ansible_host=[IP_ADDR]    ansible_port=[SSH_PORT]  ansible_user=root

## Use Python 3 interpreter to make it works with Debian 9/Ubuntu 16.04 or newer.

wireguard    ansible_host=[IP_ADDR]    ansible_port=[SSH_PORT]  ansible_user=root  ansible_python_interpreter=/usr/bin/python3


root@node110 Sep 06 14:34:25 /root/.../roles/mina-alber.wireguard-ansible# cat vars/main.yml 
###########################
## WireGuard Server Vars ##
###########################

wireguard_repo: "https://copr.fedorainfracloud.org/coprs/jdoss/wireguard/repo/epel-7/jdoss-wireguard-epel-7.repo"

wireguard_interface_ip: "10.0.5.1/24" # IPADDR/PREFIX
wireguard_port: "51820"

root@node110 Sep 06 14:34:42 /root/.../roles/mina-alber.wireguard-ansible# python3 --version
Python 3.6.8
root@node110 Sep 06 14:34:50 /root/.../roles/mina-alber.wireguard-ansible# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.2 LTS
Release:	18.04
Codename:	bionic
root@node110 Sep 06 14:34:59 /root/.../roles/mina-alber.wireguard-ansible#