zabbix-dnscheck

Features

This external check allows public dns records monitoring without zabbix agent or dns server access. It is also useful when you want to know if the pinged host does not exist (that's right).

• Low-Level Discovery
• Bulk items upload with zabbix-sender
• Efficient: no unnecessary processes are spawned
• Configurable

Note: for simple agent dns monitoring you should use net.dns.record

It is possible to control what data is gathered by providing arguments to the discovery script in template -> Discovery -> DNS Check Discovery -> Key. Based on that, items and triggers will be created and the script will behave differently. For simplicity's sake templates are created for general use: Workstation, Server and Mail Server. Its contents are identical, only arguments to the script differs.

Argument	Possible values	Comment
sys.argv[1]	send,	send items
	send_verbose	In verbose you can see zabbix sender output.
sys.argv[2]	e.g. example.org	DNS name of the host. {HOST.DNS} in zabbix or macro if custom template.
sys.argv[3]	e.g. Example host	Host name from host's configuration. {HOST.HOST} in zabbix or macro if custom..
sys.argv[4]	ptrYES, ptrNO	Whether gather PTR or not. Will spawn additional process for each found IP address.
sys.argv[5]	ipv6YES, ipv6NO,ipv6MAY	IPv6 records. Will not spawn additional process.
sys.argv[6]	mxYES, mxNO	MX. Will not spawn additional process.
sys.argv[7]	txtYES, txtNO	TXT. Will spawn additional process.
sys.argv[8]	Namserver	Nameserver to check (optional)

Installation

Requires python3, zabbix-sender, bind9-host (Debian) or bind-utils (Centos) packages. Uses host binary.

Take a look at script's first lines and change values if necessary. Its important to specify serverIP (server or proxy) in dnscheck-send.py.

Place scripts in externalscripts directory on your server or proxy.

mv dnscheck-resolve.py dnscheck-send.py /usr/lib/zabbix/externalscripts/

Apply necessary permissions.

chmod 750 dnscheck-resolve.py
chown root:zabbix dnscheck-resolve.py
chmod 750 dnscheck-send.py
chown root:zabbix dnscheck-send.py

Import required templates in zabbix web interface. Then assign hosts and wait.

Note: before scripts would work, zabbix server must first discover available items. It is done in 12 hour cycles by default. You can temporary decrease this parameter for testing in template -> Discovery -> DNS Check Discovery -> Update interval.

Testing

./dnscheck-resolve.py get 'pc1.example.org' 'Example workstation' ptrNO ipv6NO mxNO txtNO 8.8.8.8

Process host Example workstation with dns pc1.example.org gathering only IPv4 records.

./dnscheck-resolve.py getverb 'server.example.org' 'Example server' ptrYES ipv6YES mxNO txtNO

Verbosely process host Example server with dns server.example.org gathering IPv4, PTR and IPv6 records.

./dnscheck-resolve.py getverb 'mail.example.org' 'Example mail server' ptrYES ipv6YES mxYES txtYES

Verbosely process host Example mail server with dns mail.example.org gathering IPv4, PTR, IPv6, MX and TXT records.

These scripts were tested to work with following configurations:

• Centos 7 / Zabbix 3.0 / Python 3.4
• Debian 10 / Zabbix 5.0 / Python 3.7

Links

• http://unlicense.org