Support customising the NATS Streaming channel.

Signed-off-by: Bruno Miguel Custódio <brunomcustodio@gmail.com>

gateway/Gopkg.lock

@@ -112,15 +112,15 @@
   version = "0.12.0"
 
 [[projects]]
-  digest = "1:28692259e850b777eb6db1ee8937ecd14d4d1172204d583f8b71ac11455a737e"
+  digest = "1:b7c06bdc590871ac5c88f8a85acc9f892c994d6327de311ec5871aaecb6f9489"
   name = "github.com/openfaas/nats-queue-worker"
   packages = [
     "handler",
     "nats",
   ]
   pruneopts = "UT"
-  revision = "8dff9cb169398f4f131565702c7f695e76247ed6"
+  revision = "dea1c90b8cc66dc73597b7531a4fd29a32b5f88c"
-  version = "0.8.2"
+  version = "0.9.0"
 
 [[projects]]
   digest = "1:eb04f69c8991e52eff33c428bd729e04208bf03235be88e4df0d88497c6861b9"

gateway/Gopkg.toml

@@ -12,7 +12,7 @@
 
 [[constraint]]
   name = "github.com/openfaas/nats-queue-worker"
-  version = "0.8.2"
+  version = "0.9.0"
 
 [[constraint]]
   name = "github.com/prometheus/client_golang"

gateway/README.md

@@ -73,6 +73,7 @@ The gateway can be configured through the following environment variables:
 | `faas_nats_address`          | The host at which NATS Streaming can be reached. Required for asynchronous mode |
 | `faas_nats_port`    | The port at which NATS Streaming can be reached. Required for asynchronous mode |
 | `faas_nats_cluster_name` | The name of the target NATS Streaming cluster. Defaults to `faas-cluster` for backwards-compatibility |
+| `faas_nats_channel` | The name of the NATS Streaming channel to use. Defaults to `faas-request` for backwards-compatibility |
 | `faas_prometheus_host`         | Host to connect to Prometheus. Default: `"prometheus"` |
 | `faas_promethus_port`         | Port to connect to Prometheus. Default: `9090` |
 | `direct_functions`            | `true` or `false` -  functions are invoked directly over overlay network by DNS name without passing through the provider |

gateway/server.go

@@ -135,7 +135,7 @@ func main() {
 
 		defaultNATSConfig := natsHandler.NewDefaultNATSConfig(maxReconnect, interval)
 
-		natsQueue, queueErr := natsHandler.CreateNATSQueue(*config.NATSAddress, *config.NATSPort, *config.NATSClusterName, defaultNATSConfig)
+		natsQueue, queueErr := natsHandler.CreateNATSQueue(*config.NATSAddress, *config.NATSPort, *config.NATSClusterName, *config.NATSChannel, defaultNATSConfig)
 		if queueErr != nil {
 			log.Fatalln(queueErr)
 		}

gateway/types/readconfig.go

@@ -106,6 +106,14 @@ func (ReadConfig) Read(hasEnv HasEnv) (*GatewayConfig, error) {
 		cfg.NATSClusterName = &v
 	}
 
+	faasNATSChannel := hasEnv.Getenv("faas_nats_channel")
+	if len(faasNATSChannel) > 0 {
+		cfg.NATSChannel = &faasNATSChannel
+	} else {
+		v := "faas-request"
+		cfg.NATSChannel = &v
+	}
+
 	prometheusPort := hasEnv.Getenv("faas_prometheus_port")
 	if len(prometheusPort) > 0 {
 		prometheusPortVal, err := strconv.Atoi(prometheusPort)
@@ -197,6 +205,9 @@ type GatewayConfig struct {
 	// The name of the NATS Streaming cluster. Required for async mode.
 	NATSClusterName *string
 
+	// NATSChannel is the name of the NATS Streaming channel used for asynchronous function invocations.
+	NATSChannel *string
+
 	// Host to connect to Prometheus.
 	PrometheusHost string
 

gateway/types/readconfig_test.go

@@ -255,6 +255,12 @@ func TestRead_UseNATS(t *testing.T) {
 		t.Fail()
 	}
 
+	wantNATSChannel := "faas-request"
+	if *config.NATSChannel != wantNATSChannel {
+		t.Logf("faas_nats_channel: want %s, got %s", wantNATSChannel, *config.NATSChannel)
+		t.Fail()
+	}
+
 	defaults.Setenv("faas_nats_cluster_name", "example-nats-cluster")
 	config, _ = readConfig.Read(defaults)
 
@@ -263,6 +269,15 @@ func TestRead_UseNATS(t *testing.T) {
 		t.Logf("faas_nats_cluster_name: want %s, got %s", wantNATSClusterName, *config.NATSClusterName)
 		t.Fail()
 	}
+
+	defaults.Setenv("faas_nats_channel", "foo")
+	config, _ = readConfig.Read(defaults)
+
+	wantNATSChannel = "foo"
+	if *config.NATSChannel != wantNATSChannel {
+		t.Logf("faas_nats_channel: want %s, got %s", wantNATSChannel, *config.NATSChannel)
+		t.Fail()
+	}
 }
 
 func TestRead_UseNATSBadPort(t *testing.T) {

gateway/vendor/github.com/openfaas/nats-queue-worker/handler/handler.go

@@ -7,18 +7,23 @@ import (
 )
 
 // CreateNATSQueue ready for asynchronous processing
-func CreateNATSQueue(address string, port int, clusterName string, clientConfig NATSConfig) (*NATSQueue, error) {
+func CreateNATSQueue(address string, port int, clusterName, channel string, clientConfig NATSConfig) (*NATSQueue, error) {
 	var err error
 	natsURL := fmt.Sprintf("nats://%s:%d", address, port)
 	log.Printf("Opening connection to %s\n", natsURL)
 
 	clientID := clientConfig.GetClientID()
 
+	// If 'channel' is empty, use the previous default.
+	if channel == "" {
+		channel = "faas-request"
+	}
+
 	queue1 := NATSQueue{
 		ClientID:       clientID,
 		ClusterID:      clusterName,
 		NATSURL:        natsURL,
-		Topic:          "faas-request",
+		Topic:          channel,
 		maxReconnect:   clientConfig.GetMaxReconnect(),
 		reconnectDelay: clientConfig.GetReconnectDelay(),
 		ncMutex:        &sync.RWMutex{},