mokujin90 / gosnmp

A simple SNMP library written in GoLang

gosnmp

GoSNMP is a simple SNMP client library, written fully in Go. Currently it supports only GetRequest (with the rest GetNextRequest, SetRequest in the pipe line). Support for traps is also in the plans.

Install

The easiest way to install is via go get:

go get github.com/alouca/gosnmp

License

Some parts of the code are borrowed by the Golang project (specifically some functions for unmarshaling BER responses), which are under the same terms and conditions as the Go language, which are marked appropriately in the source code. The rest of the code is under the BSD license.

See the LICENSE file for more details.

Usage

The library usage is pretty simple:

// Connect to 192.168.0.1 with timeout of 5 seconds

import (
	"github.com/alouca/gosnmp"
	"log"
)

s, err := gosnmp.NewGoSNMP("61.147.69.87", "public", gosnmp.Version2c, 5)
if err != nil {
	log.Fatal(err)
}
resp, err := s.Get(".1.3.6.1.2.1.1.1.0")
if err == nil {
	for _, v := range resp.Variables {
		switch v.Type {
		case gosnmp.OctetString:
			log.Printf("Response: %s : %s : %s \n", v.Name, v.Value.(string), v.Type.String())
		}
	}
}

The response value is always given as an interface{} depending on the PDU response from the SNMP server. For an example checkout examples/example.go.

Responses are a struct of the following format:

type Variable struct {
  Name  asn1.ObjectIdentifier
  Type  Asn1BER
  Value interface{}
}

Where Name is the OID encoded as an object identifier, Type is the encoding type of the response and Value is an interface{} type, with the response appropriately decoded.

SNMP BER Types can be one of the following:

type Asn1BER byte

const (
  Integer          Asn1BER = 0x02
	BitString                = 0x03
	OctetString              = 0x04
	Null                     = 0x05
	ObjectIdentifier         = 0x06
	Counter32                = 0x41
	Gauge32                  = 0x42
	TimeTicks                = 0x43
	Opaque                   = 0x44
	NsapAddress              = 0x45
	Counter64                = 0x46
	Uinteger32               = 0x47
)

GoSNMP supports most of the above values, subsequent releases will support all of them.