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####Table of Contents

  1. Overview
  2. Module Description - What the module does and why it is useful
  3. Setup - The basics of getting started with puppet_audit
  4. Usage - Configuration options and additional functionality
  5. Reference - An under-the-hood peek at what the module is doing and how
  6. Limitations - OS compatibility, etc.
  7. Development - Guide for contributing to the module

##Overview

This module allows you to be alerted of changes to files and directories that you need to audit but do not necessarily want to change.

##Module Description

Puppet has had Tripwire-style functionality for a while, but the previous implementation (using the audit metaparameter in conjunction with the puppet inspect subcommend) had some significant drawbacks. This module provides similar benefits to the puppet inspect method, but does so using regular Puppet resources and reports, so its provides a clean, supported workflow.

It implements a few defined types, puppet_audit::directory, puppet_audit::link, and puppet_audit::file, which will check (but not manage) properties that you assert about the each instantiation of the type. Differences between the desired state and the actual state on the system will trigger a report entry describing the difference, but because each resource has the noop metaparameter set to true, will not change the state of the filesystem.

This is useful if, for example, you work in an environment where a security team is interested in using Puppet for Tripwire / Samhain / Nessus style functionality but does not want to actively manage the files in question, and simply be alerted using Puppet's reporting mechanism if there has been drift.

The puppet_audit module packages 3 defined resource types to check the presence / integrity of sensitive files, directories and symbolic links.

A standalone module which consumes hiera hash data pertinent to files, directories and symbolic links in the following example form:

##Setup

Install the module from the forge and classify appropriate nodes with a profile class i.e.

 class profile::puppet_audit {
   include puppet_audit

  # Setup local hash variables pulling data from Hiera hashes.
   $security_files_hash = hiera_hash('profile::puppet_audit_files',{})
   $security_directories_hash = hiera_hash('profile::puppet_audit_directories',{})
   $security_links_hash = hiera_hash('profile::puppet_audit_links',{})
  
  # Check files, directories, and links using create resources function.
  
   create_resources('puppet_audit::file', $security_files_hash)
   create_resources('puppet_audit::directory', $security_directories_hash)
   create_resources('puppet_audit::link', $security_links_hash)
  }

Hiera data for example usage:

  ---
  'profile::puppet_audit_files':
    '/etc/passwd':
      checksum_value: '0c4305ed79b2292299b00ebcb691a0e4'
      group: '0'
      mode: '644'
      owner: '0'
    '/etc/group':
      checksum_value: '{md5}51c9981096429f8e37696806c7b0050f'
      group: '0'
      mode: '644'
      owner: '0'
  'profile::puppet_audit_directories':
    '/etc/rc.d':
      group: '0'
      owner: '0'
      mode: '755'
    '/etc/xinetd.d':
      group: '0'
      owner: '0'
      mode: '755'
  'profile::puppet_audit_links':
    '/etc/grub.conf':
      group: '0'
      owner: '0'
      mode: '777'
      target: '../boot/grub/grub.conf'

###What puppet_audit affects

  • Each file, symlink, or directory you want to be informed about needs to have its "correct" properties asserted in the instantiation of its defined type

  • Additionally, for files, the md5 sum needs to be asserted using the $fileMD5 attribute. You can generate this from the system using the md5sum(1) command on Linux systems, the md5 command on Mac OS X, or openssl md5 < *(filename)* on systems which do not have either of these utilities installed.

  • using tags / tagmail?

###Setup Requirements OPTIONAL

None.

###Beginning with puppet_audit

This module expands and abstracts the "Alternate Compliance Workflow" origionally outlined in the Puppet Enterprise documentation.

layout: default title: "Compliance alternate workflow" canonical: "/pe/latest/compliance_alt.html" toc: false

This page describes an alternate workflow which will allow you to maintain baseline states and audit changes in your Puppet-controlled infrastructure.

Workflow in brief

  • Instead of writing audit manifests: Write manifests that describe the desired baseline state(s). This is identical to writing Puppet manifests to manage systems: you use the resource declaration syntax to describe the desired state of each significant resource.
  • Instead of running Puppet agent in its default mode: Make it sync the significant resources in no-op mode, which can be done for the entire Puppet run, or per-resource. (See below.) This causes Puppet to detect changes and simulate changes, without automatically enforcing the desired state.
  • In the console: Look for "pending" events and node status. "Pending" is how the console represents detected differences and simulated changes.

Controlling your manifests

As part of a solid change control process, you should be maintaining your Puppet manifests in a version control system like Git. A well-designed branch structure in version control will allow changes to your manifests to be tracked, controlled, and audited.

No-op features

Puppet resources or catalogs can be marked as "no-op" before they are applied by the agent nodes. This means that the user describes a desired state for the resource, and Puppet will detect and report any divergence from this desired state. Puppet will report what should change to bring the resource into the desired state, but it will not make those changes automatically.

  • To set an individual resource as no-op, set the noop metaparameter to true.

      file {'/etc/sudoers':
    owner => root,
    group => root,
    mode  => 0600,
    noop  => true,
  }

    This allows you to mix enforced resources and no-op resources in the same Puppet run.

  • To do an entire Puppet run in no-op, set the noop setting to true. This can be done in the [agent] block of puppet.conf, or as a --noop command-line flag. If you are running Puppet agent in the default daemon mode, you would set no-op in puppet.conf.

In the console

In the console, you can locate the changes Puppet has detected by looking for "pending" nodes, reports, and events. A "pending" status means Puppet has detected a change and simulated a fix, but has not automatically managed the resource.

You can find a pending status in the following places:

  • The node summary, which lists the number of nodes on which changes were detected.

  • The list of recent reports, which uses an orange asterisk to show reports in which changes were detected.

  • The log and events tabs of any report containing pending events. These tabs will show you what changes were detected, and how they differ from the desired system state described in your manifests.

After detection

When a Puppet node reports no-op events, this means someone has made changes to a no-op resource that has a desired state desribed. Generally, this either means an unauthorized change has been made, or an authorized change was made but the manifests have not yet been updated to contain the change. You will need to either:

  • Revert the system to the desired state (possibly by running Puppet agent with --no-noop).
  • Edit your manifests to contain the new desired state, and check the changed manifests into version control.

Before detection

However, your admins should generally be changing the manifests before making authorized changes. This serves as documentation of the change's approval.

Summary

In this alternate workflow, you are essentially still maintaining baselines of your systems' desired states. However, instead of maintaining an abstract baseline by approving changes in the console, you are maintaining concrete baselines in readable Puppet code, which can be audited via version control records.

##Usage

puppet_audit examples/profiles shows desired usage. ##Reference

Please see: https://docs.puppetlabs.com/hiera/1/lookup_types.html for information on encapsulating data in hiera hashes.

##Limitations

  • The files, links and directories you create using puppet_audit cannot also be managed in other parts of your Puppet configuration as regular resources; doing so will cause a "duplicate resource" error.
  • This module has been tested on Darwin [OSX] and Centos 6.5. Although it simply leverages Puppet resources in a known pattern.

##Development

Contributions welcome!

Only the list of files, directories and symlinks specified in the appropriate hiera hashes.

##Release Notes/Contributors/Etc

abuxton dbmoore trlinkin