initial commit

snmp/snmp.go

@@ -0,0 +1,98 @@
+package snmp
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/dchote/snmp-mqtt/config"
+
+	"github.com/eclipse/paho.mqtt.golang"
+	"github.com/soniah/gosnmp"
+)
+
+var ()
+
+// Init contains the generic read/publish loop
+func Init() {
+	opts := mqtt.NewClientOptions().AddBroker(config.ConnectionString()).SetClientID(config.ClientID)
+	opts.SetKeepAlive(2 * time.Second)
+	opts.SetPingTimeout(1 * time.Second)
+
+	client := mqtt.NewClient(opts)
+	if token := client.Connect(); token.Wait() && token.Error() != nil {
+		panic(token.Error())
+	}
+
+	var wg sync.WaitGroup
+
+	for {
+		wg.Add(1)
+
+		go func() {
+			defer wg.Done()
+
+			for _, endpoint := range config.SNMPMap.SNMPEndpoints {
+				log.Println("Polling endpoint " + endpoint.Endpoint)
+
+				snmp := gosnmp.GoSNMP{}
+
+				snmp.Target = endpoint.Endpoint
+				snmp.Port = 161
+				snmp.Version = gosnmp.Version2c
+				snmp.Community = endpoint.Community
+
+				snmp.Timeout = time.Duration(5 * time.Second)
+				err := snmp.Connect()
+				if err != nil {
+					log.Fatal("SNMP Connect err: %v\n", err)
+				}
+
+				oids := []string{}
+
+				for _, oidTopic := range endpoint.OIDTopics {
+					oids = append(oids, oidTopic.OID)
+				}
+
+				result, err := snmp.Get(oids)
+				if err != nil {
+					log.Printf("error in Get: %s", err)
+				} else {
+					for _, variable := range result.Variables {
+						for _, oidTopic := range endpoint.OIDTopics {
+							if strings.Compare(oidTopic.OID, variable.Name) == 0 {
+								convertedValue := ""
+
+								switch variable.Type {
+								case gosnmp.OctetString:
+									convertedValue = string(variable.Value.([]byte))
+								default:
+									convertedValue = fmt.Sprintf("%d", gosnmp.ToBigInt(variable.Value))
+								}
+
+								log.Printf("%s = %s", oidTopic.Topic, convertedValue)
+								token := client.Publish(config.TopicPrefix+"/"+oidTopic.Topic, 0, false, convertedValue)
+
+								token.Wait()
+								if token.Error() != nil {
+									log.Fatal(token.Error())
+								}
+							}
+						}
+					}
+				}
+				snmp.Conn.Close()
+			}
+
+		}()
+
+		time.Sleep(time.Duration(config.Interval) * time.Second)
+	}
+
+	wg.Wait()
+
+	client.Disconnect(250)
+	time.Sleep(1 * time.Second)
+}