Logstash heartbeat plugin -> Zabbix monitoring

1_logstash.conf

input {
  heartbeat {
    message => "epoch"
    interval => 10
    add_field => { "zabbix_host" => "host.example.tld" "zabbix_key" => "ls_heartbeat" }
    tags => [ "heartbeat" ]
  }
}

filter { }

output {
  if "heartbeat" in [tags] {
    zabbix {
      zabbix_server_host => "localhost"
      zabbix_host => "zabbix_host"
      zabbix_key => "zabbix_key"
      zabbix_value => "clock"
    }
  } else {
  # ... Other outputs
  }
}  

2_zabbix.item.txt

Name: Logstash Heartbeat
Type: Zabbix trapper
Key: ls_heartbeat
Type of information: Numeric unsigned
Data type: Decimal
Units: unixtime

3_get_lag.py

#!/usr/bin/env python

# Send calculated difference between "lastclock" (which is the epoch timestamp when Zabbix recorded "lastvalue")
# and "lastvalue" (which must also be an epoch timestamp) to "lag_key" at the ls_host on
# the specified Zabbix server.

from zoop import *
from zbxsend import Metric, send_to_zabbix

api = zoop(url='http://zabbix.example.tld/zabbix', username='user', password='supersecretpassphrase')

ls_host = 'host.example.tld'
item_key = 'ls_heartbeat'
lag_key = 'ls_heartbeat_lag'
zabbix_server = 'localhost'
zabbix_port = 10051

zabbixhost = api.host()
zabbixhost.get(name=ls_host)

zabbixitem = api.item()
zabbixitem.get(hostid=zabbixhost["hostid"], key_=item_key)

diff = int(zabbixitem["lastclock"]) - int(zabbixitem["lastvalue"])
send_to_zabbix([Metric('host.example.tld', lag_key, diff)], zabbix_server, zabbix_port)

4_lag_item.txt

Name: Logstash Heartbeat Lag
Type: Zabbix trapper
Key: ls_heartbeat_lag
Type of information: Numeric unsigned
Data type: Decimal
Units: s

@untergeek I would love to see some small guide, how to setup Zabbix monitoring for logstash.

Or perhaps you can recommend easier way to monitor if logstash is working or not?