gistfile1.md

Introducing Hiera!

Hiera allows us to define data structures that can then be accessed in a class and passed to a template.

This PR shows how it can be used to pass in different URLs for apache rewrites dependant on the environments domain.

Hiera's main config lives in /etc/puppet/hiera.yaml

---
:backends:
  - yaml

:yaml:
  :datadir: '/etc/puppet/hieradata'

:hierarchy:
  - "%{domain}/supporter_url_redirects"
  - common

"%{domain}/supporter_url_redirects" references /etc/puppet/hieradata/edheroy.com/supporter_url_redirects.yaml

common references /etc/puppet/hieradata/common.yaml

/etc/puppet/hieradata/edheroy.com/supporter_url_redirects.yaml looks like this

---
au:
  url: 'http://core-au.edheroy.com'
gb:
  url: 'http://core-gb.edheroy.com'
nz:
  url: 'http://core-nz.edheroy.com'
us:
  url: 'http://core-us.edheroy.com'

So in the webapp-vhost.pp we can do this:

$gb_redirect = hiera('gb')

Then in the template we can access it like this:

<%= @gb_redirect['url'] %>