Ansible/Host Naming
From charlesreid1
Main article: Ansible/Hosts
Automatically Labeling Hosts
As the number of hosts grows, we may want to deal with numbered hosts instead of individually-named hosts.
Numbering Hosts
Vagrant allows the use of bracketed range notation to automatically label a large number of hosts with integers:
[web] web[1:20].example.com
To zero-pad the integers,
[web] web[01:20].example.com
Lettering Hosts
Likewise, letters can also be used:
[web] web-[a-q].example.com
(last letter is however many letters you need.)
Example
As an example, we can slim down the following inventory (hosts) file:
[production] delaware.example.com georgia.example.com maryland.example.com newhampshire.example.com newjersey.example.com newyork.example.com northcarolina.example.com pennsylvania.example.com rhodeisland.example.com virginia.example.com [staging] ontario.example.com quebec.example.com [vagrant] vagrant1 ansible_host=127.0.0.1 ansible_port=2222 vagrant2 ansible_host=127.0.0.1 ansible_port=2200 vagrant3 ansible_host=127.0.0.1 ansible_port=2201 [lb] delaware.example.com [web] georgia.example.com newhampshire.example.com newjersey.example.com ontario.example.com vagrant1 [task] newyork.example.com northcarolina.example.com maryland.example.com ontario.example.com vagrant2 [rabbitmq] pennsylvania.example.com quebec.example.com vagrant3 [db] rhodeisland.example.com virginia.example.com quebec.example.com vagrant3
Now, using numbered ranges:
[production] prod[1:10].example.com [staging] stage[1:2].example.com [vagrant] vagrant1 ansible_host=127.0.0.1 ansible_port=2222 vagrant2 ansible_host=127.0.0.1 ansible_port=2200 vagrant3 ansible_host=127.0.0.1 ansible_port=2201 [lb] prod1.example.com [web] prod[2:4].example.com stage1.example.com vagrant1 [task] prod[5:7].example.com stage1.example.com vagrant2 [rabbitmq] prod8.example.com stage2.example.com vagrant3 [db] prod[9:10].example.com stage2.example.com vagrant3
Flags
