Properly check for errors

Signed-off-by: Knut Ahlers <knut@ahlers.me>

fs20.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -34,13 +35,13 @@ func publishFS20ToCUL(client mqtt.Client, msg mqtt.Message) {
 }
 
 func publishFS20ToMQTT(housecode, device, command string) error {
-	tok := brokerClient.Publish(
+	return errors.Wrap(
-		strings.Join([]string{"culmqtt", fmt.Sprintf("%s%s", housecode, device), "state"}, "/"),
+		mqttTokToErr(brokerClient.Publish(
-		0x01, // QOS Level 1: At least once
+			strings.Join([]string{"culmqtt", fmt.Sprintf("%s%s", housecode, device), "state"}, "/"),
-		true,
+			0x01, // QOS Level 1: At least once
-		command,
+			true,
+			command,
+		)),
+		"publishing message",
 	)
-
-	tok.Wait()
-	return tok.Error()
 }

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/Luzifer/rconfig/v2 v2.2.1
 	github.com/eclipse/paho.mqtt.golang v1.3.2
 	github.com/jacobsa/go-serial v0.0.0-20180131005756-15cf729a72d4
+	github.com/pkg/errors v0.9.1
 	github.com/sirupsen/logrus v1.7.0
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/net v0.0.0-20210119194325-5f4716e94777 // indirect

go.sum

@@ -8,6 +8,8 @@ github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0U
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/jacobsa/go-serial v0.0.0-20180131005756-15cf729a72d4 h1:G2ztCwXov8mRvP0ZfjE6nAlaCX2XbykaeHdbT6KwDz0=
 github.com/jacobsa/go-serial v0.0.0-20180131005756-15cf729a72d4/go.mod h1:2RvX5ZjVtsznNZPEt4xwJXNJrM3VTZoQf7V6gk0ysvs=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sirupsen/logrus v1.7.0 h1:ShrD1U9pZB12TX0cVy0DtePoCH97K8EtX+mg7ZARUtM=
 github.com/sirupsen/logrus v1.7.0/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=

main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"time"
 
 	"github.com/Luzifer/rconfig/v2"
 	"github.com/jacobsa/go-serial/serial"
@@ -13,12 +14,13 @@ import (
 
 var (
 	cfg = struct {
-		CULDevice      string `flag:"cul-device" default:"/dev/ttyACM0" description:"TTY of the CUL to connect to"`
+		CULDevice      string        `flag:"cul-device" default:"/dev/ttyACM0" description:"TTY of the CUL to connect to"`
-		LogLevel       string `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
+		LogLevel       string        `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
-		MQTTHost       string `flag:"mqtt-host" default:"tcp://127.0.0.1:1883" description:"Connection URI for the broker"`
+		MQTTHost       string        `flag:"mqtt-host" default:"tcp://127.0.0.1:1883" description:"Connection URI for the broker"`
-		MQTTUser       string `flag:"mqtt-user" default:"" description:"Username for broker connection"`
+		MQTTUser       string        `flag:"mqtt-user" default:"" description:"Username for broker connection"`
-		MQTTPass       string `flag:"mqtt-pass" default:"" description:"Password for broker connection"`
+		MQTTPass       string        `flag:"mqtt-pass" default:"" description:"Password for broker connection"`
-		VersionAndExit bool   `flag:"version" default:"false" description:"Prints current version and exits"`
+		MQTTTimeout    time.Duration `flag:"mqtt-timeout" default:"2s" description:"Timeout for MQTT actions"`
+		VersionAndExit bool          `flag:"version" default:"false" description:"Prints current version and exits"`
 	}{}
 
 	port io.ReadWriteCloser

mqtt.go

@@ -1,6 +1,11 @@
 package main
 
-import mqtt "github.com/eclipse/paho.mqtt.golang"
+import (
+	"errors"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	log "github.com/sirupsen/logrus"
+)
 
 var brokerClient mqtt.Client
 
@@ -12,6 +17,19 @@ func init() {
 
 	brokerClient = mqtt.NewClient(opts)
 
-	brokerClient.Connect().Wait()
+	if err := mqttTokToErr(brokerClient.Connect()); err != nil {
-	brokerClient.Subscribe("culmqtt/+/send", 0x01, publishFS20ToCUL)
+		log.WithError(err).Fatal("Connect to MQTT broker")
+	}
+
+	if err := mqttTokToErr(brokerClient.Subscribe("culmqtt/+/send", 0x01, publishFS20ToCUL)); err != nil {
+		log.WithError(err).Fatal("Subscribe to topic")
+	}
+}
+
+func mqttTokToErr(tok mqtt.Token) error {
+	if !tok.WaitTimeout(cfg.MQTTTimeout) {
+		return errors.New("command timed out")
+	}
+
+	return tok.Error()
 }