NRPE Protocol description

Question

I need to query a nrpe nagios server from a Java application remotely just as check_nrpe would do:

check_nrpe -H 192.***.***.*** -p 56** -c "check_load"

When I say "from a Java application" I mean I want the results to be received and processed at my Java application. The first idea I had was to call the "check_nrpe" command from my application and retrieve its output and return value but I would like more a standalone solution where no external programs are called.

I don't need to wait for state changes, just eventually check the monitor state. Since I have been unable to locate any Java library (should I try JNRPE?), I would like to implement the protocol check_nrpe and nrpe daemon use to communicate.

Have any of you tried this before? In that case, do you have a description of this protocol?

If your answers are negative I will try to analize the protocol using whireshark but any clue will be much appreciated.

Answer 1

An explanation of NRPE protocol from Andreas Marschke blog, The NRPE Protocol explained (on gitHub too)

Anyway, JNRPE have a full working implementation of the protocol, you can download jcheck_nrpe-2.0.3-RC5 source code and take a look at jcheck_nrpe-2.0.3-RC5\src\main\java\it\jnrpe\client\JNRPEClient.java class for a sample client who's using jnrpe-lib-1.0.1-RC5.

jnrpe-lib have two concrete classes which implements the protocol request and response

• JNRPERequest.java
• JNRPEResponse.java

The full protocol implementation classes can be found at jnrpe-lib-1.0.1-RC5\src\main\java\it\jnrpe\net\ folder