Fail2ban plugin for traefik with X-Real-Ip support

This plugin is an implementation of the fail2ban mechanism as a middleware plugin for Traefik.

This is a fork of fail2ban project, to propose X-Real-Ip headers implementation.

Configuration

Whitelist

You can whitelist some IP using this:

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testData:
  whitelist:
    files:
      - "tests/test-ipfile.txt"
    ip:
      - "::1"
      - "127.0.0.1"

Where you can use some IP in an array of files or directly in the configuration.

Blacklist

Like whitelist, you can blacklist some IP using this:

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testData:
  blacklist:
    files:
      - "tests/test-ipfile.txt"
    ip:
      - "::1"
      - "127.0.0.1"

Where you can use some IP in an array of files or directly in the configuration.

Fail2ban

We plan to use all default fail2ban configuration but at this time only a few features are implemented:

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testData:
  rules:
    urlregexps:
    - regexp: "/no"
      mode: block
    - regexp: "/yes"
      mode: allow
    bantime: "3h"
    findtime: "10m"
    maxretry: 4
    enabled: true
    xrealip: true

Where:

• findtime: is the time slot used to count requests (if there is too many requests with the same ip in this slot of time, the ip goes into ban). You can use 'smart' strings: "4h", "2m", "1s", ...
• bantime: correspond to the amount of time the IP is in Ban mode.
• maxretry: number of request before Ban mode.
• enabled: allow to enable or disable the plugin (must be set to true to enable the plugin).
• urlregexp: a regexp list to block / allow requests with regexps on the url
• xrealip: use X-Real-Ip http header value, instead of kernel visible IP source

URL Regexp

Urlregexp are used to defined witch part of your website will be either allowed, blocked or filtered :

• allow : all requests where the url match the regexp will be forwarded to the backend without any check
• block : all requests where the url match the regexp will be stopped

No definitions

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testData:
  rules:
    bantime: "3h"
    findtime: "10m"
    maxretry: 4
    enabled: true
    xrealip: true

By default, fail2ban will be applied.

Multiple definition

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testData:
  rules:
    urlregexps:
    - regexp: "/whoami"
      mode: allow
    - regexp: "/do-not-access"
      mode: block
    bantime: "3h"
    findtime: "10m"
    maxretry: 4
    enabled: true
    xrealip: true

In the case where you define multiple regexp on the same url, the order of process will be :

1. Block
2. Allow

In this example, all requests to /do-not-access will be denied and all requests to /whoami will be allowed without any fail2ban interaction.

Schema

First request, IP is added to the Pool, and the findtime timer is started:

A |------------->
  ↑

Second request, findtime is not yet finished thus the request is fine:

A |--x---------->
     ↑

Third request, maxretry is now full, this request is fine but the next wont.

A |--x--x------->
        ↑

Fourth request, too bad, now it's jail time, next request will go through after bantime:

A |--x--x--x---->
           ↓
B          |------------->

Fifth request, the IP is in Ban mode, nothing happen:

A |--x--x--x---->
B          |--x---------->
              ↑

Last request, the bantime is now over, another findtime is started:

A |--x--x--x---->            |------------->
                             ↑
B          |--x---------->

How to dev

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$ docker compose up

Initial authors

Tom Moulard	Clément David	Martin Huvelle	Alexandre Bossut-Lasry