fail2ban

This is a quick guide on how to setup fail2ban for Home Assistant. This was originally in the forum but I created this here for people.

First install fail2ban. On Debian/Ubuntu this would be apt-get install fail2ban. On other distros you can google it.

Then make sure logging is enabled in your configuration.yaml file for your Home Assistant instance:

logger:
  default: critical
  logs:
    homeassistant.components.http: warning

Next we will be creating these three files :

/etc/fail2ban/fail2ban.local
/etc/fail2ban/filter.d/hass.local
/etc/fail2ban/jail.local

Contents of /etc/fail2ban/fail2ban.local:

[Definition]
logtarget = SYSLOG

Contents of /etc/fail2ban/filter.d/hass.local:

[INCLUDES]
before = common.conf

[Definition]
failregex = ^%(__prefix_line)s.*Login attempt or request with an invalid password from <HOST>.*$

ignoreregex =

[Init]
datepattern = ^%%y-%%m-%%d %%H:%%M:%%S

Contents of /etc/fail2ban/jail.local (Note that you’ll need to change the logpath to match your logfile which will be different from the path listed.):

[hass-iptables]
enabled = true
filter = hass
action = iptables-allports[name=HASS]
logpath = /opt/hass-prod-cfg/home-assistant.log
maxretry = 5

Finally restart fail2ban : sudo systemctl restart fail2ban

Check your log to make sure it read in your settings : tail -100 /var/log/syslog|grep fail

If all is well you should see this from your syslog:

May 24 20:58:01 homeauto fail2ban.server[14997]: INFO Stopping all jails
May 24 20:58:02 homeauto fail2ban.jail[14997]: INFO Jail 'sshd' stopped
May 24 20:58:02 homeauto fail2ban-client[15206]: Shutdown successful
May 24 20:58:02 homeauto fail2ban.server[14997]: INFO Exiting Fail2ban
May 24 20:58:02 homeauto fail2ban-client[15213]: 2017-05-24 20:58:02,342 fail2ban.server         [15215]: INFO    Starting Fail2ban v0.9.6
May 24 20:58:02 homeauto fail2ban-client[15213]: 2017-05-24 20:58:02,343 fail2ban.server         [15215]: INFO    Starting in daemon mode
May 24 20:58:02 homeauto fail2ban.server[15217]: INFO Changed logging target to SYSLOG (/dev/log) for Fail2ban v0.9.6
May 24 20:58:02 homeauto fail2ban.database[15217]: INFO Connected to fail2ban persistent database '/var/lib/fail2ban/fail2ban.sqlite3'
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Creating new jail 'sshd'
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Jail 'sshd' uses pyinotify {}
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Initiated 'pyinotify' backend
May 24 20:58:02 homeauto fail2ban.actions[15217]: INFO Set banTime = 600
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set findtime = 600
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set maxRetry = 5
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Added logfile = /var/log/auth.log
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set jail log file encoding to UTF-8
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set maxlines = 10
May 24 20:58:02 homeauto fail2ban.server[15217]: INFO Jail sshd is not a JournalFilter instance
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Creating new jail 'hass-iptables'
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Jail 'hass-iptables' uses pyinotify {}
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Initiated 'pyinotify' backend
May 24 20:58:02 homeauto fail2ban.actions[15217]: INFO Set banTime = 600
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set findtime = 600
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set maxRetry = 5
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Added logfile = /opt/hass-prod-cfg/home-assistant.log
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Set jail log file encoding to UTF-8
May 24 20:58:02 homeauto fail2ban.filter[15217]: INFO Date pattern set to `'^%y-%m-%d %H:%M:%S'`: `^Year2-Month-Day 24hour:Minute:Second`
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Jail 'sshd' started
May 24 20:58:02 homeauto fail2ban.jail[15217]: INFO Jail 'hass-iptables' started

That’s it!

If you want to read more about fail2ban, some links are below: