#firewall
####Table of Contents
- Overview - What is the Firewall module?
- Module Description - What does the module do?
- Setup - The basics of getting started with Firewall
- Usage - Configuration and customization options
- Reference - An under-the-hood peek at what the module is doing
- Limitations - OS compatibility, etc.
- Development - Guide for contributing to the module
##Overview
The Firewall module lets you manage firewall rules with Puppet.
##Module Description
PuppetLabs' Firewall introduces the resource firewall, which is used to manage and configure firewall rules from within the Puppet DSL. This module offers support for iptables, ip6tables, and ebtables.
The module also introduces the resource firewallchain, which allows you to manage chains or firewall lists. At the moment, only iptables and ip6tables chains are supported.
##Setup
###What Firewall affects:
- every node running a firewall
- system's firewall settings
- connection settings for managed nodes
- unmanaged resources (get purged)
- site.pp
###Setup Requirements
Firewall uses Ruby-based providers, so you must have pluginsync enabled.
###Beginning with Firewall
To begin, you need to provide some initial top-scope configuration to ensure your firewall configurations are ordered properly and you do not lock yourself out of your box or lose any configuration.
Persistence of rules between reboots is handled automatically, although there are known issues with ip6tables on older Debian/Ubuntu, as well as known issues with ebtables.
In your site.pp (or some similarly top-scope file), set up a metatype to purge unmanaged firewall resources. This will clear any existing rules and make sure that only rules defined in Puppet exist on the machine.
resources { "firewall":
purge => true
}
Next, set up the default parameters for all of the firewall rules you will be establishing later. These defaults will ensure that the pre and post classes (you will be setting up in just a moment) are run in the correct order to avoid locking you out of your box during the first puppet run.
Firewall {
before => Class['my_fw::post'],
require => Class['my_fw::pre'],
}
You also need to declare the my_fw::pre & my_fw::post classes so that dependencies are satisfied. This can be achieved using an External Node Classifier or the following
class { ['my_fw::pre', 'my_fw::post']: }
Finally, you should include the firewall class to ensure the correct packages are installed.
class { 'firewall': }
Now to create the my_fw::pre and my_fw::post classes. Firewall acts on your running firewall, making immediate changes as the catalog executes. Defining default pre and post rules allows you provide global defaults for your hosts before and after any custom rules; it is also required to avoid locking yourself out of your own boxes when Puppet runs. This approach employs a whitelist setup, so you can define what rules you want and everything else is ignored rather than removed.
The pre class should be located in my_fw/manifests/pre.pp and should contain any default rules to be applied first.
class my_fw::pre {
Firewall {
require => undef,
}
# Default firewall rules
firewall { '000 accept all icmp':
proto => 'icmp',
action => 'accept',
}->
firewall { '001 accept all to lo interface':
proto => 'all',
iniface => 'lo',
action => 'accept',
}->
firewall { '002 accept related established rules':
proto => 'all',
state => ['RELATED', 'ESTABLISHED'],
action => 'accept',
}
}
The rules in pre should allow basic networking (such as ICMP and TCP), as well as ensure that existing connections are not closed.
The post class should be located in my_fw/manifests/post.pp and include any default rules to be applied last.
class my_fw::post {
firewall { '999 drop all':
proto => 'all',
action => 'drop',
before => undef,
}
}
To put it all together: the before parameter in Firewall {} ensures my_fw::post is run before any other rules and the the require parameter ensures my_fw::pre is run after any other rules. So the run order is:
- run the rules in
my_fw::pre - run your rules (defined in code)
- run the rules in
my_fw::post
###Upgrading
####Upgrading from version 0.2.0 and newer
Upgrade the module with the puppet module tool as normal:
puppet module upgrade puppetlabs/firewall
####Upgrading from version 0.1.1 and older
Start by upgrading the module using the puppet module tool:
puppet module upgrade puppetlabs/firewall
Previously, you would have required the following in your site.pp (or some other global location):
# Always persist firewall rules
exec { 'persist-firewall':
command => $operatingsystem ? {
'debian' => '/sbin/iptables-save > /etc/iptables/rules.v4',
/(RedHat|CentOS)/ => '/sbin/iptables-save > /etc/sysconfig/iptables',
},
refreshonly => true,
}
Firewall {
notify => Exec['persist-firewall'],
before => Class['my_fw::post'],
require => Class['my_fw::pre'],
}
Firewallchain {
notify => Exec['persist-firewall'],
}
resources { "firewall":
purge => true
}
With the latest version, we now have in-built persistence, so this is no longer needed. However, you will still need some basic setup to define pre & post rules.
resources { "firewall":
purge => true
}
Firewall {
before => Class['my_fw::post'],
require => Class['my_fw::pre'],
}
class { ['my_fw::pre', 'my_fw::post']: }
class { 'firewall': }
Consult the the documentation below for more details around the classes my_fw::pre and my_fw::post.
##Usage
There are two kinds of firewall rules you can use with Firewall: default rules and application-specific rules. Default rules apply to general firewall settings, whereas application-specific rules manage firewall settings of a specific application, node, etc.
All rules employ a numbering system in the resource's title that is used for ordering. When titling your rules, make sure you prefix the rule with a number.
000 this runs first
999 this runs last
###Default rules
You can place default rules in either my_fw::pre or my_fw::post, depending on when you would like them to run. Rules placed in the pre class will run first, rules in the post class, last.
Depending on the provider, the title of the rule can be stored using the comment feature of the underlying firewall subsystem. Values can match /^\d+[[:alpha:][:digit:][:punct:][:space:]]+$/.
####Examples of default rules
Basic accept ICMP request example:
firewall { "000 accept all icmp requests":
proto => "icmp",
action => "accept",
}
Drop all:
firewall { "999 drop all other requests":
action => "drop",
}
###Application-specific rules
Application-specific rules can live anywhere you declare the firewall resource. It is best to put your firewall rules close to the service that needs it, such as in the module that configures it.
You should be able to add firewall rules to your application-specific classes so firewalling is performed at the same time when the class is invoked.
For example, if you have an Apache module, you could declare the class as below
class apache {
firewall { '100 allow http and https access':
port => [80, 443],
proto => tcp,
action => accept,
}
# ... the rest of your code ...
}
When someone uses the class, firewalling is provided automatically.
class { 'apache': }
###Other rules
You can also apply firewall rules to specific nodes. Usually, you will want to put the firewall rule in another class and apply that class to a node. But you can apply a rule to a node.
node 'foo.bar.com' {
firewall { '111 open port 111':
dport => 111
}
}
You can also do more complex things with the firewall resource. Here we are doing some NAT configuration.
firewall { '100 snat for network foo2':
chain => 'POSTROUTING',
jump => 'MASQUERADE',
proto => 'all',
outiface => "eth0",
source => '10.1.2.0/24',
table => 'nat',
}
In the below example, we are creating a new chain and forwarding any port 5000 access to it.
firewall { '100 forward to MY_CHAIN':
chain => 'INPUT',
jump => 'MY_CHAIN',
}
# The namevar here is in the format chain_name:table:protocol
firewallchain { 'MY_CHAIN:filter:IPv4':
ensure => present,
}
firewall { '100 my rule':
chain => 'MY_CHAIN',
action => 'accept',
proto => 'tcp',
dport => 5000,
}
###Additional Information
You can access the inline documentation:
puppet describe firewall
Or
puppet doc -r type
(and search for firewall)
##Reference
Classes:
Types:
Facts:
###Class: firewall
This class is provided to do the basic setup tasks required for using the firewall resources.
At the moment this takes care of:
- iptables-persistent package installation
You should include the class for nodes that need to use the resources in this module. For example
class { 'firewall': }
####ensure
Indicates the state of iptables on your system, allowing you to disable iptables if desired.
Can either be running or stopped. Default to running.
###Type: firewall
This type provides the capability to manage firewall rules within puppet.
For more documentation on the type, access the 'Types' tab on the Puppet Labs Forge:
http://forge.puppetlabs.com/puppetlabs/firewall#types
###Type:: firewallchain
This type provides the capability to manage rule chains for firewalls.
For more documentation on the type, access the 'Types' tab on the Puppet Labs Forge:
http://forge.puppetlabs.com/puppetlabs/firewall#types
###Fact: ip6tables_version
The module provides a Facter fact that can be used to determine what the default version of ip6tables is for your operating system/distribution.
###Fact: iptables_version
The module provides a Facter fact that can be used to determine what the default version of iptables is for your operating system/distribution.
###Fact: iptables_persistent_version
Retrieves the version of iptables-persistent from your OS. This is a Debian/Ubuntu specific fact.
##Limitations
While we aim to support as low as Puppet 2.6.x (for now), we recommend installing the latest Puppet version from the Puppetlabs official repos.
Please note, we only aim support for the following distributions and versions - that is, we actually do ongoing system tests on these platforms:
- Redhat 5.9 and 6.4
- Debian 6.0 and 7.0
- Ubuntu 10.04 and 12.04
If you want a new distribution supported feel free to raise a ticket and we'll consider it. If you want an older revision supported we'll also consider it, but don't get insulted if we reject it. Specifically, we will not consider Redhat 4.x support - its just too old.
If you really want to get support for your OS we suggest writing any patch fix yourself, and for continual system testing if you can provide a sufficient trusted Veewee template we could consider adding such an OS to our ongoing continuous integration tests.
Also, as this is a 0.x release the API is still in flux and may change. Make sure you read the release notes before upgrading.
Bugs can be reported using Github Issues:
http://github.com/puppetlabs/puppetlabs-firewall/issues
##Development
Puppet Labs modules on the Puppet Forge are open projects, and community contributions are essential for keeping them great. We can’t access the huge number of platforms and myriad of hardware, software, and deployment configurations that Puppet is intended to serve.
We want to keep it as easy as possible to contribute changes so that our modules work in your environment. There are a few guidelines that we need contributors to follow so that we can have a chance of keeping on top of things.
You can read the complete module contribution guide on the Puppet Labs wiki.
For this particular module, please also read CONTRIBUTING.md before contributing.
Currently we support:
- iptables
- ip6tables
- ebtables (chains only)
But plans are to support lots of other firewall implementations:
- FreeBSD (ipf)
- Mac OS X (ipfw)
- OpenBSD (pf)
- Cisco (ASA and basic access lists)
If you have knowledge in these technologies, know how to code, and wish to contribute to this project, we would welcome the help.
###Testing
Make sure you have:
- rake
- bundler
Install the necessary gems:
bundle install
And run the tests from the root of the source code:
rake test
If you have a copy of Vagrant 1.1.0 you can also run the system tests:
RSPEC_SET=debian-606-x64 rake spec:system
RSPEC_SET=centos-58-x64 rake spec:system
Note: system testing is fairly alpha at this point, your mileage may vary.