Documentation

Fail2ban Input Plugin

This plugin gathers the count of failed and banned IP addresses using fail2ban by running the fail2ban-client command.

The fail2ban-client requires root access, so please make sure to either allow Telegraf to run that command using sudo without a password or by running telegraf as root (not recommended).

Introduced in: Telegraf v1.4.0 Tags: network, system OS support: all

Global configuration options

In addition to the plugin-specific configuration settings, plugins support additional global and plugin configuration settings. These settings are used to modify metrics, tags, and field or create aliases and configure ordering, etc. See the CONFIGURATION.md for more details.

Configuration

# Read metrics from fail2ban.
[[inputs.fail2ban]]
  ## Use sudo to run fail2ban-client
  # use_sudo = false

  ## Use the given socket instead of the default one
  # socket = "/var/run/fail2ban/fail2ban.sock"

Using sudo

Make sure to set use_sudo = true in your configuration file.

You will also need to update your sudoers file. It is recommended to modify a file in the /etc/sudoers.d directory using visudo:

sudo visudo -f /etc/sudoers.d/telegraf

Add the following lines to the file, these commands allow the telegraf user to call fail2ban-client without needing to provide a password and disables logging of the call in the auth.log. Consult man 8 visudo and man 5 sudoers for details.

Cmnd_Alias FAIL2BAN = /usr/bin/fail2ban-client status, /usr/bin/fail2ban-client status *
telegraf  ALL=(root) NOEXEC: NOPASSWD: FAIL2BAN
Defaults!FAIL2BAN !logfile, !syslog, !pam_session

Metrics

  • fail2ban
    • tags:
      • jail
    • fields:
      • failed (integer, count)
      • banned (integer, count)

Example Output

fail2ban,jail=sshd failed=5i,banned=2i 1495868667000000000

Execute the binary directly

# fail2ban-client status sshd
Status for the jail: sshd
|- Filter
|  |- Currently failed: 5
|  |- Total failed:     20
|  `- File list:        /var/log/secure
`- Actions
   |- Currently banned: 2
   |- Total banned:     10
   `- Banned IP list:   192.168.0.1 192.168.0.2

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