binford2k / sockpuppet

Introduction

Alert: this module is not currently usable

This is a module that allows you to drastically reduce the load on your Puppet Master if you fall within a very narrow use case.

Two things go into the building of a Puppet catalog: the code that is compiled, and the data that goes into it. If both remain constant, then the resulting catalog should be exactly the same and we don't need to compile it again; the Agent can simply apply the last cached catalog.

This means that the Agent node continues to be managed but only requests an updated catalog when necessary.

This module expects you to write a config_version script that returns the codebase revision of all code that goes into building a catalog. This likely includes the entire Puppet modulepath and any Hiera datasources.

Features:

• REST endpoint exposing the Puppet Master's computed config_version
• Puppet subcommand to replace the Agent, while only downloading a new catalog when the cache is invalidated.

Limitations

This is still in early development. Pull requests are welcome!

• The Master's REST endpoint is not currently operational.
• The sockpuppet face depends on the core catalog face, which is currently broken.

Usage

On the Master:

• Install the module
• Configure a config_version to return the codebase revision of anything that could affect the compiled catalog
  • Puppet codebase
  • Hiera datasources
  • etc.

On the Agent:

• Install the module
• Add a volatile_facts setting to puppet.conf that contains a list of all facts that change often and should not trigger a recompile.
• Disable the Puppet Agent daemon
• Configure a cron job to run puppet sockpuppet on the schedule of your choice.

Suggested default list of volatile facts.

[main]
  volatile_facts = memoryfree,swapfree,swapfree_mb,memoryfree_mb,uptime,uptime_days,uptime_hours,uptime_seconds

Contact

• Author: Ben Ford
• Email: [email protected]
• Twitter: @binford2k
• IRC (Freenode): binford2k