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Copyright 2014 Hewlett-Packard Development Company, L.P.

This work is licensed under a Creative Commons Attribution 3.0 Unported License. http://creativecommons.org/licenses/by/3.0/legalcode

Refactor openstack_project::{server,base,template}

Problem Description

Right now there are three ‘main’ classes in puppet. They are

openstack_project::server openstack_project::base openstack_project::template

All three of these control resources that matter to most systems. Server contains template, template contains base. Then usually an application has a class that wraps server.

The problem with this is that if you want to make a change to a resource that is controlled in base, parameters must be added to allow you pass in changes to the application class, then to the server class, then to the template class, finally picking it up again in the base class.

Proposed Change

I propose we flatten server, base, and template to a single class called server. All the parameters can be flattened as well, and if statements added to allow someone or something who really wanted ‘template’ to get just those resoruces. (nodepool prepare node jumps directly into template, its the only place I’ve found so far that base or template are called directly)

Additionally I propose we pull the openstack_project::server invocation out of the application classes and put it in the node definition. Example:

node 'review.openstack.org' {
  class { 'openstack_project::server':
    iptables_tcp_public_ports => [80, 443, 29418],
    sysadmins                 => hiera('sysadmins', 'default'),
  }
  class {'openstack_project::review':
    # ... other params ..
  }
}

When every node in the environment takes the same openstack_project::server class, that means that the differences between two nodes can be thought of as the array of parameters passed into those servers. It makes servers more like each other and easier to reason about. It also frees the application class to do what it does best, which is set up the application. o_p::server handles all the base configuration and o_p::application handles the application.

Alternatives

We could remain the same. We could flatten server, base, and template without pulling the openstack_project::server invocation out of the application class.

Implementation

Server class would be expanded to include the parameters and resources of base class and template class. New parameters would be added so that there is a way to get just the resources of template and base.

Application classes would be modified to not need server class, site.pp would be modified.

Assignee(s)

Primary assignee:
nibalizer

Gerrit Topic

Use Gerrit topic “downstream-puppet” for all patches related to this spec.

git-review -t downstream-puppet

Work Items

  • base.pp flatten
  • template.pp flatten
  • refactor of places where those classes are used
  • refactor of server.pp
  • application specific refactors + site.pp changes

Repositories

No new git repos

Servers

Puppet change only

DNS Entries

Puppet change only

Documentation

Largely should be transparent to anyone who isn’t mucking around in infra internals

Security

No security implications

Testing

apply-test will provide acceptance testing

Dependencies

No known dependencies