mqtt stuff 3

src/locsrv/mqtt/mqtt.go

@@ -0,0 +1,56 @@
+package mqtt
+
+import (
+  "log"
+  "os"
+  "fmt"
+  MQTT "github.com/eclipse/paho.mqtt.golang"
+  "github.com/google/uuid"
+)
+
+
+
+type MqttHandle struct {
+  initialized bool
+  pubTopic string
+  client MQTT.Client
+}
+
+func New() *MqttHandle {
+  var mqttHandle MqttHandle
+  mqttHandle.initialized = true
+
+  mqttOpts := MQTT.NewClientOptions().
+    AddBroker(os.Getenv("MQTT_BROKER")).
+    SetClientID(fmt.Sprintf("locsrv-%s", uuid.New())).
+    SetConnectRetry(true)
+  mqttHandle.client= MQTT.NewClient(mqttOpts)
+  if token := mqttHandle.client.Connect(); token.Wait() && token.Error() != nil {
+    log.Printf("Unable to connect to broker, error %v", token.Error())
+    mqttHandle.initialized = false
+  }
+
+  mqttHandle.pubTopic = os.Getenv("MQTT_TOPIC")
+  if mqttHandle.pubTopic != "" {
+    log.Printf("No topic set")
+    mqttHandle.initialized = false
+  }
+  return &mqttHandle
+}
+
+func (self *MqttHandle) Publish(message string) error {
+  if ! self.initialized {
+    return fmt.Errorf("MQTT connection not initialized")
+  }
+
+  token := self.client.Publish(self.pubTopic, 0, false, message) 
+  token.Wait()
+  if token.Error() != nil {
+    return fmt.Errorf("MQTT publish failed: %v", token.Error())
+  }
+
+  return nil
+}
+
+
+