iptables-formula

This module manages your firewall using iptables with pillar configured rules. Thanks to the nature of Pillars it is possible to write global and local settings (e.g. enable globally, configure locally)

Pull requests are welcome for other platforms (or other improvements ofcourse!)

Usage

All the configuration for the firewall is done via pillar (pillar.example).

Enable globally: pillars/firewall.sls

firewall:
  enabled: True
  install: True  
  strict: True

Allow SSH: pillars/firewall/ssh.sls

firewall:
  services:
    ssh:
      block_nomatch: False
      ips_allow:
        - 192.168.0.0/24
        - 10.0.2.2/32

Allow an entire class such as your internal network:

  whitelist:
    networks:
      ips_allow:
        - 10.0.0.0/8

Salt combines both and effectively enables your firewall and applies the rules.

Notes:

• Setting install to True will install iptables and iptables-perrsistent for you
• Strict mode means: Deny everything except explicitly allowed (use with care!)
• block_nomatch: With non-strict mode adds in a "REJECT" rule below the accept rules, otherwise other traffic to that service is still allowed. Can be defined per-service or globally, defaults to False.
• Servicenames can be either port numbers or servicenames (e.g. ssh, zabbix-agent, http) and are available for viewing/configuring in /etc/services

Using iptables.service

Salt can't merge pillars, so you can only define firewall:services in once place. With the firewall.service state and stateconf, you can define pillars for different services and include and extend the iptables.service state with the parent parameter to enable a default firewall configuration with special rules for different services.

pillars/otherservice.sls

otherservice:
  firewall:
    http:
      block_nomatch: False
      ips_allow:
        - 0.0.0.0/0

states/otherservice.sls

#!stateconf yaml . jinja

include:
  - firewall.service

extend:
  firewall.service::sls_params:
    stateconf.set:
      - parent: otherservice

Using iptables.nat

You can use nat for interface.

#!stateconf yaml . jinja

# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.18.0/24 -j MASQUERADE

  nat:
    eth0:
      ips_allow:
        - 192.168.18.0/24