Ansible host patterns
Source: https://docs.ansible.com/ansible/latest/user_guide/intro_patterns.html
Groups
| Description | Pattern(s) | Targets |
|---|---|---|
|
All hosts One host Multiple hosts One group |
all (or *) host1 host1,host2 (or host1:host2) webservers |
|
| Multiple groups | webservers,dbservers | all hosts in webservers plus all hosts in dbservers |
| Excluding groups | webservers,!atlanta | all hosts in webservers except those in atlanta |
| Intersection of groups | webservers,&staging | any hosts in webservers that are also in staging |
You can use either a comma (,) or a colon (:) to separate a list of hosts. The comma is preferred when dealing with ranges and IPv6 addresses.
Wildcards
You can use wildcard patterns with FQDNs or IP addresses, as long as the hosts are named in your inventory by FQDN or IP address:
192.0.\*
\*.example.com
\*.com
You can mix wildcard patterns and groups at the same time:
one*.com,dbservers
Regular expressions
You can specify a pattern as a regular expression by starting the pattern with ~:
~(web|db).*\.example\.com
List all matching ansible hosts
ansible-playbook <playbook> --list-hosts will list all hosts a playbook will target.
And here’s a convenient snippet Andreas Lutro shared to list all hosts, without any other data:
ansible-inventory -i inventory/ --list | jq -r '.. | .hosts? // empty | .[]' | sort | uniq