Publish ConnState message on gateway (un)subscribe.

This introduces a new topic hierarchy gateway/ID/state/STATE for
publishing state messages. State messages are published with the
retained flag.

The ConnState message is published to gateway/ID/state/conn and contains
the state ONLINE or OFFLINE.

Author: brocaar

cmd/chirpstack-gateway-bridge/cmd/configfile.go

@@ -221,6 +221,14 @@ marshaler="{{ .Integration.Marshaler }}"
   # Event topic template.
   event_topic_template="{{ .Integration.MQTT.EventTopicTemplate }}"
 
+  # State topic template.
+  #
+  # States are sent by the gateway as retained MQTT messages so that the last
+  # message will be stored by the MQTT broker. When set to a blank string, this
+  # feature will be disabled. This feature is only supported when using the
+  # generic authentication type.
+  state_topic_template="{{ .Integration.MQTT.StateTopicTemplate }}"
+
   # Command topic template.
   command_topic_template="{{ .Integration.MQTT.CommandTopicTemplate }}"
 

cmd/chirpstack-gateway-bridge/cmd/root.go

@@ -57,6 +57,7 @@ func init() {
 	viper.SetDefault("integration.mqtt.auth.type", "generic")
 
 	viper.SetDefault("integration.mqtt.event_topic_template", "gateway/{{ .GatewayID }}/event/{{ .EventType }}")
+	viper.SetDefault("integration.mqtt.state_topic_template", "gateway/{{ .GatewayID }}/state/{{ .StateType }}")
 	viper.SetDefault("integration.mqtt.command_topic_template", "gateway/{{ .GatewayID }}/command/#")
 	viper.SetDefault("integration.mqtt.keep_alive", 30*time.Second)
 	viper.SetDefault("integration.mqtt.max_reconnect_interval", time.Minute)

cmd/chirpstack-gateway-bridge/cmd/root_run.go

@@ -47,6 +47,8 @@ func run(cmd *cobra.Command, args []string) error {
 	log.WithField("signal", <-sigChan).Info("signal received")
 	log.Warning("shutting down server")
 
+	integration.GetIntegration().Stop()
+
 	return nil
 }
 

go.mod

@@ -3,7 +3,7 @@ module github.com/brocaar/chirpstack-gateway-bridge
 go 1.16
 
 require (
-	github.com/brocaar/chirpstack-api/go/v3 v3.8.1
+	github.com/brocaar/chirpstack-api/go/v3 v3.9.7
 	github.com/brocaar/lorawan v0.0.0-20201030140234-f23da2d4a303
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
 	github.com/eclipse/paho.mqtt.golang v1.3.0

go.sum

@@ -51,8 +51,8 @@ github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kB
 github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJmJgSg28kpZDP6UIiPt0e0Oz0kqKNGyRaWEPv84=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
-github.com/brocaar/chirpstack-api/go/v3 v3.8.1 h1:8xNpG/GZqiL8XYkkAUWYNZJu7yn5SamK6oPBx1hCQe0=
-github.com/brocaar/chirpstack-api/go/v3 v3.8.1/go.mod h1:ex/wqXQaClwDMa2zDN6crp9ZiMGc1GMVQhjxiB+OJcg=
+github.com/brocaar/chirpstack-api/go/v3 v3.9.7 h1:n5Zte6zIg+qbqtb4dwp3vGQwIXpXsk5nMR4WwMUcLgA=
+github.com/brocaar/chirpstack-api/go/v3 v3.9.7/go.mod h1:v8AWP19nOJK4rwJsr1+weDfpUc4UNLbRh8Eygn4Oh00=
 github.com/brocaar/lorawan v0.0.0-20201030140234-f23da2d4a303 h1:LkE19tFPfDaRh1HIKWLCZKSBZNonMu0rIOJPCLvEjC0=
 github.com/brocaar/lorawan v0.0.0-20201030140234-f23da2d4a303/go.mod h1:CciUmQHIpUYTHHMeICtyamM7d+47VV+WBZ5ReDozpoc=
 github.com/caarlos0/ctrlc v1.0.0 h1:2DtF8GSIcajgffDFJzyG15vO+1PuBWOMUdFut7NnXhw=

internal/config/config.go

@@ -58,6 +58,7 @@ type Config struct {
 		MQTT struct {
 			EventTopicTemplate      string        `mapstructure:"event_topic_template"`
 			CommandTopicTemplate    string        `mapstructure:"command_topic_template"`
+			StateTopicTemplate      string        `mapstructure:"state_topic_template"`
 			KeepAlive               time.Duration `mapstructure:"keep_alive"`
 			MaxReconnectInterval    time.Duration `mapstructure:"max_reconnect_interval"`
 			TerminateOnConnectError bool          `mapstructure:"terminate_on_connect_error"`

internal/integration/integration.go

@@ -47,6 +47,9 @@ type Integration interface {
 	// PublishEvent publishes the given event.
 	PublishEvent(lorawan.EUI64, string, uuid.UUID, proto.Message) error
 
+	// PublishState publishes the given state as retained message.
+	PublishState(lorawan.EUI64, string, proto.Message) error
+
 	// SetDownlinkFrameFunc sets the DownlinkFrame handler func.
 	SetDownlinkFrameFunc(func(gw.DownlinkFrame))
 

internal/integration/mqtt/auth/auth.go

@@ -8,13 +8,18 @@ import (
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
 	"github.com/pkg/errors"
+
+	"github.com/brocaar/lorawan"
 )
 
 // Authentication defines the authentication interface.
 type Authentication interface {
 	// Init applies the initial configuration.
 	Init(*mqtt.ClientOptions) error
 
+	// GetGatewayID returns the GatewayID if available.
+	GetGatewayID() *lorawan.EUI64
+
 	// Update updates the authentication options.
 	Update(*mqtt.ClientOptions) error
 

internal/integration/mqtt/auth/azure_iot_hub.go

@@ -15,6 +15,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/brocaar/chirpstack-gateway-bridge/internal/config"
+	"github.com/brocaar/lorawan"
 )
 
 // See:
@@ -201,6 +202,12 @@ func (a *AzureIoTHubAuthentication) Init(opts *mqtt.ClientOptions) error {
 	return nil
 }
 
+// GetGatewayID returns the GatewayID if available.
+// TODO: implement.
+func (a *AzureIoTHubAuthentication) GetGatewayID() *lorawan.EUI64 {
+	return nil
+}
+
 // Update updates the authentication options.
 func (a *AzureIoTHubAuthentication) Update(opts *mqtt.ClientOptions) error {
 	if a.authType == authTypeSymmetric {

internal/integration/mqtt/auth/gcp_cloud_iot_core.go

@@ -11,6 +11,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/brocaar/chirpstack-gateway-bridge/internal/config"
+	"github.com/brocaar/lorawan"
 )
 
 // GCPCloudIoTCoreAuthentication implements the Google Cloud IoT Core authentication.
@@ -59,6 +60,12 @@ func (a *GCPCloudIoTCoreAuthentication) Init(opts *mqtt.ClientOptions) error {
 	return nil
 }
 
+// GetGatewayID returns the GatewayID if available.
+// TODO: implement.
+func (a *GCPCloudIoTCoreAuthentication) GetGatewayID() *lorawan.EUI64 {
+	return nil
+}
+
 // Update updates the authentication options.
 func (a *GCPCloudIoTCoreAuthentication) Update(opts *mqtt.ClientOptions) error {
 	token := jwt.NewWithClaims(a.siginingMethod, jwt.StandardClaims{

internal/integration/mqtt/auth/generic.go

@@ -6,8 +6,10 @@ import (
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
 	"github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
 
 	"github.com/brocaar/chirpstack-gateway-bridge/internal/config"
+	"github.com/brocaar/lorawan"
 )
 
 // GenericAuthentication implements a generic MQTT authentication.
@@ -59,6 +61,24 @@ func (a *GenericAuthentication) Init(opts *mqtt.ClientOptions) error {
 	return nil
 }
 
+// GetGatewayID returns the GatewayID if available.
+func (a *GenericAuthentication) GetGatewayID() *lorawan.EUI64 {
+	if a.clientID == "" {
+		return nil
+	}
+
+	// Try to decode the client ID as gateway ID.
+	var gatewayID lorawan.EUI64
+	if err := gatewayID.UnmarshalText([]byte(a.clientID)); err != nil {
+		log.WithError(err).WithFields(log.Fields{
+			"client_id": a.clientID,
+		}).Warning("integration/mqtt/auth: could not decode client ID to gateway ID")
+		return nil
+	}
+
+	return &gatewayID
+}
+
 // Update updates the authentication options.
 func (a *GenericAuthentication) Update(opts *mqtt.ClientOptions) error {
 	return nil

internal/integration/mqtt/auth/generic_test.go

@@ -0,0 +1,37 @@
+package auth
+
+import (
+	"testing"
+
+	"github.com/brocaar/chirpstack-gateway-bridge/internal/config"
+	"github.com/brocaar/lorawan"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGenericAuthentication(t *testing.T) {
+	gatewayID := lorawan.EUI64{1, 2, 3, 4, 5, 6, 7, 8}
+
+	var conf config.Config
+	conf.Integration.Marshaler = "json"
+	conf.Integration.MQTT.EventTopicTemplate = "gateway/{{ .GatewayID }}/event/{{ .EventType }}"
+	conf.Integration.MQTT.StateTopicTemplate = "gateway/{{ .GatewayID }}/state/{{ .StateType }}"
+	conf.Integration.MQTT.CommandTopicTemplate = "gateway/{{ .GatewayID }}/command/#"
+	conf.Integration.MQTT.Auth.Type = "generic"
+	conf.Integration.MQTT.Auth.Generic.Servers = []string{"tcp://localhost:1883"}
+	conf.Integration.MQTT.Auth.Generic.Username = "foo"
+	conf.Integration.MQTT.Auth.Generic.Password = "bar"
+	conf.Integration.MQTT.Auth.Generic.CleanSession = true
+	conf.Integration.MQTT.Auth.Generic.ClientID = gatewayID.String()
+
+	t.Run("New", func(t *testing.T) {
+		assert := require.New(t)
+
+		auth, err := NewGenericAuthentication(conf)
+		assert.NoError(err)
+
+		t.Run("GetGatewayID", func(t *testing.T) {
+			assert := require.New(t)
+			assert.Equal(&gatewayID, auth.GetGatewayID())
+		})
+	})
+}