# iptables Cookbook

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Installs iptables and provides a custom resource for adding and removing iptables rules

## Requirements

### Platforms

- Ubuntu/Debian
- RHEL/CentOS and derivatives

### Chef

- Chef 12.10+

### Cookbooks

- none

## Recipes

### default

The default recipe will install iptables and provides a ruby script (installed in `/usr/sbin/rebuild-iptables`) to manage rebuilding firewall rules from files dropped off in `/etc/iptables.d`.

### disabled

The disabled recipe will install iptables, disable the `iptables` service (on RHEL platforms), and delete the rules directory `/etc/iptables.d`.

## Attributes

`default['iptables']['iptables_sysconfig']` and `default['iptables']['ip6tables_sysconfig']` are hashes that are used to template /etc/sysconfig/iptables-config and /etc/sysconfig/ip6tables-config. The keys must be upper case and any key / value pair included will be added to the config file.

`default['iptables']['system_ruby']` allows users to override the system ruby path if ruby is installed into a non standard location and Chef has been installed without an embedded ruby (eg. from the Gem).

## Custom Resource

### rule

The custom resource drops off a template in `/etc/iptables.d` after the `name` parameter. The rule will get added to the local system firewall through notifying the `rebuild-iptables` script. See **Examples** below.

NOTE: In the 1.0 release of this cookbook the iptables_rule definition was converted to a custom resource. This changes the behavior of disabling iptables rules. Previously a rule could be disabled by specifying `enable false`. You must now specify `action :disable`

## Usage

Add `recipe[iptables]` to your runlist to ensure iptables is installed / running and to ensure that the `rebuild-iptables` script is on the system. Then create use iptables_rule to add individual rules. See **Examples**.

Since certain chains can be used with multiple tables (e.g., _PREROUTING_), you might have to include the name of the table explicitly (i.e., _*nat_, _*mangle_, etc.), so that the `/usr/sbin/rebuild-iptables` script can infer how to assemble final ruleset file that is going to be loaded. Please note, that unless specified otherwise, rules will be added under the **filter** table by default.

### Examples

To enable port 80, e.g. in an `my_httpd` cookbook, create the following template:

```text
# Port 80 for http
-A FWR -p tcp -m tcp --dport 80 -j ACCEPT
```

This template would be located at: `my_httpd/templates/default/http.erb`. Then within your recipe call:

```ruby
iptables_rule 'http' do
  action :enable
end
```

To redirect port 80 to local port 8080, e.g., in the aforementioned `my_httpd` cookbook, create the following template:

```text
*nat
# Redirect anything on eth0 coming to port 80 to local port 8080
-A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080
```

Please note, that we explicitly add name of the table (being _*nat_ in this example above) where the rules should be added.

This would most likely go in the cookbook, `my_httpd/templates/default/http_8080.erb`. Then to use it in `recipe[httpd]`:

```ruby
iptables_rule 'http_8080' do
  action :enable
end
```

To create a rule without using a template resource use the `lines` property (you can optionally specify `table` when using `lines`):

```ruby
iptables_rule 'http_8080' do
  lines '-A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080'
  table :nat
end
```

To get attribute-driven rules you can (for example) feed a hash of attributes into named iptables.d files like this:

```ruby
node.default['iptables']['http_80'] = '-A FWR -p tcp -m tcp --dport 80 -j ACCEPT'
node.default['iptables']['http_443'] = [
  '# an example with multiple lines',
  '-A FWR -p tcp -m tcp --dport 443 -j ACCEPT',
]

node['iptables'].map do |rule_name, rule_body|
  iptables_rule rule_name do
    lines [ rule_body ].flatten.join("\n")
  end
end
```

## Chefspec Matchers

- enable_iptables_rule(resource_name)
- disable_iptables_rule(resource_name)

## License & Authors

**Author:** Cookbook Engineering Team ([cookbooks@chef.io](mailto:cookbooks@chef.io))

**Copyright:** 2008-2016, Chef Software, Inc.

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you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

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distributed under the License is distributed on an "AS IS" BASIS,
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