community.general.iptables_state module – Save iptables state into a file or restore it from a file

Note

This module is part of the community.general collection (version 7.5.2).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install community.general. You need further requirements to be able to use this module, see Requirements for details.

To use it in a playbook, specify: community.general.iptables_state.

New in community.general 1.1.0

Synopsis

  • iptables is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel.

  • This module handles the saving and/or loading of rules. This is the same as the behaviour of the iptables-save and iptables-restore (or ip6tables-save and ip6tables-restore for IPv6) commands which this module uses internally.

  • Modifying the state of the firewall remotely may lead to loose access to the host in case of mistake in new ruleset. This module embeds a rollback feature to avoid this, by telling the host to restore previous rules if a cookie is still there after a given delay, and all this time telling the controller to try to remove this cookie on the host through a new connection.

Note

This module has a corresponding action plugin.

Aliases: system.iptables_state

Requirements

The below requirements are needed on the host that executes this module.

  • iptables

  • ip6tables

Parameters

Parameter

Comments

counters

boolean

Save or restore the values of all packet and byte counters.

When true, the module is not idempotent.

Choices:

  • false ← (default)

  • true

ip_version

string

Which version of the IP protocol this module should apply to.

Choices:

  • "ipv4" ← (default)

  • "ipv6"

modprobe

path

Specify the path to the modprobe program internally used by iptables related commands to load kernel modules.

By default, /proc/sys/kernel/modprobe is inspected to determine the executable’s path.

noflush

boolean

For state=restored, ignored otherwise.

If false, restoring iptables rules from a file flushes (deletes) all previous contents of the respective table(s). If true, the previous rules are left untouched (but policies are updated anyway, for all built-in chains).

Choices:

  • false ← (default)

  • true

path

path / required

The file the iptables state should be saved to.

The file the iptables state should be restored from.

state

string / required

Whether the firewall state should be saved (into a file) or restored (from a file).

Choices:

  • "saved"

  • "restored"

table

string

When state=restored, restore only the named table even if the input file contains other tables. Fail if the named table is not declared in the file.

When state=saved, restrict output to the specified table. If not specified, output includes all active tables.

Choices:

  • "filter"

  • "nat"

  • "mangle"

  • "raw"

  • "security"

wait

integer

Wait N seconds for the xtables lock to prevent instant failure in case multiple instances of the program are running concurrently.

Attributes

Attribute

Support

Description

action

Support: full

Indicates this has a corresponding action plugin so some parts of the options can be executed on the controller.

async

Support: full

Supports being used with the async keyword.

check_mode

Support: full

Can run in check_mode and return changed status prediction without modifying target.

diff_mode

Support: none

Will return details on what has changed (or possibly needs changing in check_mode), when in diff mode.

Notes

Note

  • The rollback feature is not a module option and depends on task’s attributes. To enable it, the module must be played asynchronously, i.e. by setting task attributes poll to 0, and async to a value less or equal to ANSIBLE_TIMEOUT. If async is greater, the rollback will still happen if it shall happen, but you will experience a connection timeout instead of more relevant info returned by the module after its failure.

Examples

# This will apply to all loaded/active IPv4 tables.
- name: Save current state of the firewall in system file
  community.general.iptables_state:
    state: saved
    path: /etc/sysconfig/iptables

# This will apply only to IPv6 filter table.
- name: save current state of the firewall in system file
  community.general.iptables_state:
    ip_version: ipv6
    table: filter
    state: saved
    path: /etc/iptables/rules.v6

# This will load a state from a file, with a rollback in case of access loss
- name: restore firewall state from a file
  community.general.iptables_state:
    state: restored
    path: /run/iptables.apply
  async: "{{ ansible_timeout }}"
  poll: 0

# This will load new rules by appending them to the current ones
- name: restore firewall state from a file
  community.general.iptables_state:
    state: restored
    path: /run/iptables.apply
    noflush: true
  async: "{{ ansible_timeout }}"
  poll: 0

# This will only retrieve information
- name: get current state of the firewall
  community.general.iptables_state:
    state: saved
    path: /tmp/iptables
  check_mode: true
  changed_when: false
  register: iptables_state

- name: show current state of the firewall
  ansible.builtin.debug:
    var: iptables_state.initial_state

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

applied

boolean

Whether or not the wanted state has been successfully restored.

Returned: always

Sample: true

initial_state

list / elements=string

The current state of the firewall when module starts.

Returned: always

Sample: ["# Generated by xtables-save v1.8.2", "*filter", ":INPUT ACCEPT [0:0]", ":FORWARD ACCEPT [0:0]", ":OUTPUT ACCEPT [0:0]", "COMMIT", "# Completed"]

restored

list / elements=string

The state the module restored, whenever it is finally applied or not.

Returned: always

Sample: ["# Generated by xtables-save v1.8.2", "*filter", ":INPUT DROP [0:0]", ":FORWARD DROP [0:0]", ":OUTPUT ACCEPT [0:0]", "-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT", "-A INPUT -m conntrack --ctstate INVALID -j DROP", "-A INPUT -i lo -j ACCEPT", "-A INPUT -p icmp -j ACCEPT", "-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT", "COMMIT", "# Completed"]

saved

list / elements=string

The iptables state the module saved.

Returned: always

Sample: ["# Generated by xtables-save v1.8.2", "*filter", ":INPUT ACCEPT [0:0]", ":FORWARD DROP [0:0]", ":OUTPUT ACCEPT [0:0]", "COMMIT", "# Completed"]

tables

dictionary

The iptables we have interest for when module starts.

Returned: always

Sample: {"filter": [":INPUT ACCEPT", ":FORWARD ACCEPT", ":OUTPUT ACCEPT", "-A INPUT -i lo -j ACCEPT", "-A INPUT -p icmp -j ACCEPT", "-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT", "-A INPUT -j REJECT --reject-with icmp-host-prohibited"], "nat": [":PREROUTING ACCEPT", ":INPUT ACCEPT", ":OUTPUT ACCEPT", ":POSTROUTING ACCEPT"]}

table

list / elements=string

Policies and rules for all chains of the named table.

Returned: success

Authors

  • quidame (@quidame)