Fail2ban

Plugin: python.d.plugin Module: fail2ban

Overview

Monitor Fail2ban performance for prime intrusion prevention operations. Monitor ban counts, jail statuses, and failed login attempts to ensure robust network security.

It collects metrics through reading the default log and configuration files of fail2ban.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

The fail2ban.log file must be readable by the user netdata.

• change the file ownership and access permissions.
• update `/etc/logrotate.d/fail2ban`` to persist the changes after rotating the log file.

To change the file ownership and access permissions, execute the following:

sudo chown root:netdata /var/log/fail2ban.log
sudo chmod 640 /var/log/fail2ban.log

To persist the changes after rotating the log file, add create 640 root netdata to the /etc/logrotate.d/fail2ban:

/var/log/fail2ban.log {

    weekly
    rotate 4
    compress

    delaycompress
    missingok
    postrotate
        fail2ban-client flushlogs 1>/dev/null
    endscript

    # If fail2ban runs as non-root it still needs to have write access
    # to logfiles.
    # create 640 fail2ban adm
    create 640 root netdata
}

Default Behavior

Auto-Detection

By default the collector will attempt to read log file at /var/log/fail2ban.log and conf file at /etc/fail2ban/jail.local. If conf file is not found default jail is ssh.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per Fail2ban instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
fail2ban.failed_attempts	a dimension per jail	attempts/s
fail2ban.bans	a dimension per jail	bans/s
fail2ban.banned_ips	a dimension per jail	ips

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

No action required.

Configuration

File

The configuration file name for this integration is python.d/fail2ban.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config python.d/fail2ban.conf

Options

There are 2 sections:

• Global variables
• One or more JOBS that can define multiple different instances to monitor.

The following options can be defined globally: priority, penalty, autodetection_retry, update_every, but can also be defined per JOB to override the global values.

Additionally, the following collapsed table contains all the options that can be configured inside a JOB definition.

Every configuration JOB starts with a job_name value which will appear in the dashboard, unless a name parameter is specified.

Config options

Name	Description	Default	Required
log_path	path to fail2ban.log.	/var/log/fail2ban.log	no
conf_path	path to jail.local/jail.conf.	/etc/fail2ban/jail.local	no
conf_dir	path to jail.d/.	/etc/fail2ban/jail.d/	no
exclude	jails you want to exclude from autodetection.		no
update_every	Sets the default data collection frequency.	1	no
priority	Controls the order of charts at the netdata dashboard.	60000	no
autodetection_retry	Sets the job re-check interval in seconds.	0	no
penalty	Indicates whether to apply penalty to update_every in case of failures.	yes	no
name	Job name. This value will overwrite the job_name value. JOBS with the same name are mutually exclusive. Only one of them will be allowed running at any time. This allows autodetection to try several alternatives and pick the one that works.		no

Examples

Basic

A basic example configuration.

local:
  log_path: '/var/log/fail2ban.log'
  conf_path: '/etc/fail2ban/jail.local'

Troubleshooting

Debug Mode

To troubleshoot issues with the fail2ban collector, run the python.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the python.d.plugin to debug the collector:

  ./python.d.plugin fail2ban debug trace

Debug Mode