nagios-sip-plugin

A plugin for Nagios for checking the status of a SIP server.

Features

• SIP UDP, TCP and TLS transport protocols.
• Customizable parameters (From URI, Request URI, server address, local UDP port, timeout internal).
• The replied status code can be matched against an expected value to be considered as valid.

Documentation

The plugin sends an OPTIONS and parses the response status code (or triggers timeout error).

Return values

As any Nagios plugin it must behave according to Nagios API:

OK status

The plugin returns 0 value in two cases:

• -c (expected status code) is not set and the server replies any response.
• -c is set to a specific value (i.e. "200") and the server replies the same status code.

It also prints to stdout a string to be parsed by Nagios:

OK:status code = 200

WARNING status

The plugin returns 1 value in case -c is set and the response code doesn't match its value.

It also prints to stdout:

WARNING:Received a 403 but 200 was required

CRITICAL status

The plugin returns 2 value in the following cases:

• No response at all is received from the server in the configured timeout interval (-T parameter)
• The TCP connection failed.
• An ICMP "port unreachable" message has been received in SIP UDP.
• Error resolving the server IP (when a hostname is used).
• TLS verification error when -vt parameter is set and there is not a valid PEM file in the given CA path (-ca parameter).
• Other TLS errors.

It also prints to stdout (depending on the exact error):

CRITICAL:Timeout receiving the response via UDP (Timeout::Error: execution expired)
CRITICAL:Couldn't get the server address 'not-found.org' (SocketError: getaddrinfo: Name or service not known)
CRITICAL:Timeout when connecting the server via TCP (Timeout::Error: execution expired)
...

Commandline options

~$ ./nagios-sip-plugin.rb --help

Usage mode:    nagios-sip-plugin.rb [OPTIONS]

  OPTIONS:
    -t (tls|tcp|udp)     :    Protocol to use (default 'udp').
    -s SERVER_IP     :    IP or domain of the server (required).
    -p SERVER_PORT   :    Port of the server (default '5060').
    -r REQUEST_URI   :    Request URI (default 'sip:ping@SERVER_IP:SERVER_PORT').
    -f FROM_URI      :    From URI (default 'sip:nagios@SERVER_IP').
    -c SIP_CODE      :    Expected status code (i.e: '200'). If null then any code is valid.
    -T SECONDS       :    Timeout in seconds (default '2').
    -vt              :    Verify server's TLS certificate when using SIP TLS (default false).
    -ca CA_PATH      :    Directory with public PEM files for validating server's TLS certificate (default '/etc/ssl/certs/').

  Homepage:
    https://github.com/ibc/nagios-sip-plugin

Usage example

~$ nagios-sip-plugin.rb -t udp -s 9.9.9.9 -p 5060 -r "sip:9999@myserver.org" -f "sip:nagios@myserver.org" -c 200 -T 3

~$ nagios-sip-plugin.rb -t tcp -s 9.9.9.9 -p 6060

Dependencies

• Ruby 1.8 or 1.9.

TODO

• Add retransmissions mechanism for SIP UDP transport.