blog/_posts/2020-10-07-fail2ban.md

---
title: Fail2ban
tags: [fail2ban, systemd, gitea, gotify, roundcube, filter, ban]
updated: 2020-10-07 12:24
description: Customization of Fail2ban filter, rules and settings
---

## Table of contents

<!--TOC-->

- [Table of contents](#table-of-contents)
- [Introduction](#introduction)
- [Global options](#global-options)
  - [Fail2ban](#fail2ban)
  - [Systemd service](#systemd-service)
- [Filters](#filters)
  - [Gitea](#gitea)
  - [Gotify](#gotify)
  - [Roundcube](#roundcube)
- [Jails](#jails)
  - [Gitea](#gitea-1)
  - [Gotify](#gotify-1)
  - [Roundcube](#roundcube-1)

<!--TOC-->

## Introduction

This is a list of custom filters, rules and settings I use for Fail2ban.

## Global options

### Fail2ban

- `/etc/fail2ban/jail.local`

  ```
  ignoreip = 127.0.0.1/8 ::1                          # add your local network here to avoid being locked out
  mta = sendmail                                      # you must have postfix working
  sender =                                            # add the sender email
  destemail =                                         # add the destination email
  maxretry = 3
  bantime  = 15d
  findtime  = 3600s
  banaction = iptables-allports
  action = %(action_mwl)s
  ```

### Systemd service

Follow the instructions reported [here](https://wiki.archlinux.org/index.php/Fail2ban#Service_hardening)

- `# systemctl edit fai2ban`

  ```
  # GFDL v1.3+
  # ArchWiki contributors
  # https://wiki.archlinux.org/index.php/Fail2ban

  [Service]
  PrivateDevices=yes
  PrivateTmp=yes
  ProtectHome=read-only
  ProtectSystem=strict

  ## NoNewPrivileges=yes                        # I had problems sending emails with this option enabled.

  ReadWritePaths=-/var/run/fail2ban
  ReadWritePaths=-/var/lib/fail2ban
  ReadWritePaths=-/var/log/fail2ban
  ReadWritePaths=-/var/spool/postfix/maildrop
  ReadWritePaths=-/run/xtables.lock
  CapabilityBoundingSet=CAP_AUDIT_READ CAP_DAC_READ_SEARCH CAP_NET_ADMIN CAP_NET_RAW

  [Unit]
  OnFailure=notify-unit-status@%n.service       # Optional. See https://frnmst.github.io/automated-tasks/scripts.html#notify-unit-status-py
  After=postfix.service
  Requires=postfix.service
  ```

- `/etc/fail2ban/fail2ban.local`

  ```
  # GFDL v1.3+
  # ArchWiki contributors
  # https://wiki.archlinux.org/index.php/Fail2ban

  [Definition]
  logtarget = /var/log/fail2ban/fail2ban.log
  ```

## Filters

### Gitea

- `/etc/fail2ban/filter.d/gitea.conf`

  See [https://docs.gitea.io/en-us/fail2ban-setup/](https://docs.gitea.io/en-us/fail2ban-setup/)

### Gotify

- `/etc/fail2ban/filter.d/gotify.conf`

  ```
  [Definition]
  failregex = .*?\| 401 \|.*?\|.*?<HOST> \| POST.*?"/client"
  ignoreregex = Error #01: you need to provide a valid access token or user credentials to access this api.*
  datepattern = %%Y/%%m/%%d - %%H:%%M:%%S
  ```

### Roundcube

- `/etc/fail2ban/filter.d/roundcube-auth.conf`

  See [https://raw.githubusercontent.com/fail2ban/fail2ban/bb0f732ae69894b22306dd7efa213513e3acd8a2/config/filter.d/roundcube-auth.conf](https://raw.githubusercontent.com/fail2ban/fail2ban/bb0f732ae69894b22306dd7efa213513e3acd8a2/config/filter.d/roundcube-auth.conf)

## Jails

### Gitea

- `/etc/fail2ban/jail.local`

  ```
  [gitea]
  enabled = true
  port = http,https
  filter = gitea
  logpath = /var/log/gitea/gitea.log
  ```

  See also [https://docs.gitea.io/en-us/fail2ban-setup/](https://docs.gitea.io/en-us/fail2ban-setup/)

### Gotify

- `/etc/fail2ban/jail.local`

  ```
  [gotify]
  enabled = true
  port = http,https
  filter = gotify
  logpath = /var/log/gotify/server.log
  ```

### Roundcube

- `/etc/fail2ban/jail.local`

  ```
  [roundcube]
  enabled = true
  port = http,https
  filter = roundcube-auth
  logpath = /var/log/roundcubemail/errors.log
  ```