ansible/ansible — pull request #585 by dagwieers (2012-07-12 13:53:01+00:00)
Title: Allow groups to be defined on a per-host basis

This makes it possible to define on a per-host basis what groups a host is in.
When managing a large set of systems it makes it easier to ensure each of the
systems is defined in a set of groups (e.g. production/qa/development,
linux/solaris/aix) rather than having to add systems to multiple disconnected
groups.

```yaml
- host: system01

- host: system02

- host: system03

- group: linux
hosts:
- system01
- system02

- group: solaris
hosts:
- system03

- group: production
hosts:
- system01
- system03

- group: qa
- system02

- group: dbserver
hosts:
- system01

- group: ntpserver
hosts:
- system02

- group: webserver
- system03
```

Can be redefined as:

```yaml
- host: system01
groups: [ linux, production, dbserver ]

- host: system02
groups: [ linux, qa, ntpserver ]

- host: system03
groups: [ solaris, production, webserver ]
```