README.md

@@ -0,0 +1,64 @@
+# snmp-mqtt
+
+This project is directly derived from https://github.com/dchote/snmp-mqtt
+
+A simple go app that reads SNMP values and publishes it to the specified MQTT endpoint at the specified interval.
+
+In constrast to the original version, all configuration must be provided via an environment variable containing
+a JSON string. 
+
+The MQTT configuration is part of this JSON string.
+
+The topic has been moved to the MQTT configuration and there is now only one topic for all endpoints and variables.
+
+The published message on MQTT looks like this:
+
+```
+{"device":"172.16.3.1","label":"router","variables":{"lan-in":{"label":"lan-in","variable":".1.3.6.1.2.1.31.1.1.1.6.2","value":"979673705579"},"lan-out":{"label":"lan-out","variable":".1.3.6.1.2.1.31.1.1.1.10.2","value":"1813410276168"},"wan-in":{"label":"wan-in","variable":".1.3.6.1.2.1.31.1.1.1.6.4","value":"83591215399"},"wan-out":{"label":"wan-out","variable":".1.3.6.1.2.1.31.1.1.1.10.4","value":"83741895468"}}}
+```
+
+```
+export SNMP_MQTT_CONF=$(cat config.json)
+./smq
+```
+
+An example config.json file:
+```
+{
+  "mqtt": {
+    "broker": "mqtt://172.23.1.102:1883",
+    "tlsEnable": "false",
+    "topic": "snmp"
+  },
+  "interval": 10,
+  "snmpEndpoints": [
+    {
+      "endpoint": "172.16.3.1",
+      "label": "router",
+      "community": "public",
+      "oidTopics": [
+        {
+          "oid": ".1.3.6.1.2.1.31.1.1.1.6.4",
+          "label": "wan-in",
+          "diff": "true"
+        },
+        {
+          "oid": ".1.3.6.1.2.1.31.1.1.1.10.4",
+          "label": "wan-out",
+          "diff": "true"
+        },
+        {
+          "oid": ".1.3.6.1.2.1.31.1.1.1.6.2",
+          "label": "lan-in",
+          "diff": "true"
+        },
+        {
+          "oid": ".1.3.6.1.2.1.31.1.1.1.10.2",
+          "label": "lan-out",
+          "diff": "true"
+        }
+      ]
+    }
+  ]
+}
+```

src/tsm/tsmq/tsmq.go

@@ -3,7 +3,6 @@ package tsmq
 import (
 	"log"
 	"time"
-  "strconv"
   "encoding/json"
 
 	"tsm/config"
@@ -13,15 +12,14 @@ import (
 )
 
 type variable_t struct {
-  Label string `json:"label"`
-  Variable string `json:"variable"`
-  Value string `json:"value"`
+  Name string `json:"variable"`
+  Value float64 `json:"value"`
   Unit string `json:"unit"`
   Status string `json:"status"`
 }
 
 type message_t struct {
-  Device string `json:"device"`
+  Server string `json:"server"`
   Label string `json:"label"`
   Variables map[string]variable_t `json:"variables"`
 }
@@ -34,36 +32,28 @@ func Start() {
       log.Println("Polling server " + server.Name)
 
       message := message_t {
-        Device: server.Name,
+        Server: server.Name,
         Label: server.Label,
         Variables: make(map[string]variable_t),
       }
         
+      label := "rootdisp"
       status := "Ok"
-      rootdisp := 0.0
-      stratum := 0
+      value := 0.0
       resp, err := ntp.Query(server.Name)
       if err != nil {
         status = "Error"
       } else {
-        rootdisp = resp.RootDispersion.Seconds() * 1000
-        stratum = int(resp.Stratum)
+        value = resp.RootDispersion.Seconds() * 1000
       }
 
-      message.Variables["rootdisp"] = variable_t {
-        Label: "rootdisp",
-        Variable: "",
-        Value: strconv.FormatFloat(rootdisp, 'f', 4, 64),
-        Unit: "ms",
-        Status: status,
-      }
-      message.Variables["stratum"] = variable_t {
-        Label: "stratum",
-        Variable: "",
-        Value: strconv.Itoa(stratum),
+      v := variable_t {
+        Name: label,
+        Value: value,
         Unit: "ms",
         Status: status,
       }
+      message.Variables[label] = v
 
 
       j, err := json.Marshal(message)