Ansible pattern matching doesn't work as expected - ansible

Question

I am unable to find why this simple pattern doesn't seem to match anything. I have two Ansible hosts as targets. This is my inventory file:
[web_Xubuntu]
192.168.160.128
[database_Fedora]
192.168.160.132
And this is what my YAML playbook looks like:
# Hosts: where our play will run and options it will run with
hosts: *Fedora
become: True
#gather_facts: False
# Vars: variables that will apply to the play, on all target systems
vars:
motd: "Welcome to Fedora Linux - Ansible Rocks\n"
# Tasks: the list of tasks that will be executed within the playbook
tasks:
- name: Configure a MOTD (message of the day)
copy:
content: "{{ motd }}"
dest: /etc/motd
notify: MOTD changed
# Handlers: the list of handlers that are executed as a notify key from a task
handlers:
- name: MOTD changed
debug:
msg: The MOTD was changed
On processing this playbook, Ansible reports the following error:
ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)
Syntax Error while loading YAML.
found undefined alias
The offending line appears to be:
# Hosts: where our play will run and options it will run with
hosts: *Fedora
^ here
What is the right way to use a wildcard?

Answer 1

You can use the asterisk *( wildcard) with FQDN or IP only. For example,
192.0.*
*.example.com
*.com
See Patterns: targeting hosts and groups.
Use the inventory plugin constructed if you want to run all *Fedora groups. See
shell> ansible-doc -t inventory constructed
For example, given the tree
shell> tree .
.
├── ansible.cfg
├── inventory
│   ├── 01-hosts
│   └── 02-constructed.yml
└── pb.yml
1 directory, 4 files
the inventory
shell> cat inventory/01-hosts
[web_Xubuntu]
192.168.160.128
[database_Fedora]
192.168.160.132
[web_Fedora]
192.168.160.133
the contructed plugin
shell> cat inventory/02-constructed.yml
plugin: constructed
groups:
Fedora: group_names|select('regex', '^.*Fedora$')
Test the inventory
shell> ansible-inventory -i inventory --list --yaml
all:
children:
Fedora:
hosts:
192.168.160.132: {}
192.168.160.133: {}
database_Fedora:
hosts:
192.168.160.132: {}
ungrouped: {}
web_Fedora:
hosts:
192.168.160.133: {}
web_Xubuntu:
hosts:
192.168.160.128: {}
Then, test the playbook
shell> cat pb.yml
- hosts: Fedora
gather_facts: false
tasks:
- debug:
var: inventory_hostname
gives
shell> ansible-playbook -i inventory pb.yml
PLAY [Fedora] *********************************************************************************
TASK [debug] **********************************************************************************
ok: [192.168.160.132] =>
inventory_hostname: 192.168.160.132
ok: [192.168.160.133] =>
inventory_hostname: 192.168.160.133
PLAY RECAP ************************************************************************************
192.168.160.132: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
192.168.160.133: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0