Vendor new queue-worker version

Introduces 0.4.6 of queue-worker - see upstream repo for changes.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

gateway/vendor/github.com/nats-io/go-nats-streaming/examples/stan-sub/main.go

@@ -0,0 +1,165 @@
+// Copyright 2016-2018 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"time"
+
+	"github.com/nats-io/go-nats-streaming"
+	"github.com/nats-io/go-nats-streaming/pb"
+)
+
+var usageStr = `
+Usage: stan-sub [options] <subject>
+
+Options:
+	-s, --server   <url>            NATS Streaming server URL(s)
+	-c, --cluster  <cluster name>   NATS Streaming cluster name
+	-id,--clientid <client ID>      NATS Streaming client ID
+
+Subscription Options:
+	--qgroup <name>                 Queue group
+	--seq <seqno>                   Start at seqno
+	--all                           Deliver all available messages
+	--last                          Deliver starting with last published message
+	--since <duration>              Deliver messages in last interval (e.g. 1s, 1hr)
+	         (for more information: https://golang.org/pkg/time/#ParseDuration)
+	--durable <name>                Durable subscriber name
+	--unsubscribe                   Unsubscribe the durable on exit
+`
+
+// NOTE: Use tls scheme for TLS, e.g. stan-sub -s tls://demo.nats.io:4443 foo
+func usage() {
+	log.Fatalf(usageStr)
+}
+
+func printMsg(m *stan.Msg, i int) {
+	log.Printf("[#%d] Received on [%s]: '%s'\n", i, m.Subject, m)
+}
+
+func main() {
+	var clusterID string
+	var clientID string
+	var showTime bool
+	var startSeq uint64
+	var startDelta string
+	var deliverAll bool
+	var deliverLast bool
+	var durable string
+	var qgroup string
+	var unsubscribe bool
+	var URL string
+
+	//	defaultID := fmt.Sprintf("client.%s", nuid.Next())
+
+	flag.StringVar(&URL, "s", stan.DefaultNatsURL, "The nats server URLs (separated by comma)")
+	flag.StringVar(&URL, "server", stan.DefaultNatsURL, "The nats server URLs (separated by comma)")
+	flag.StringVar(&clusterID, "c", "test-cluster", "The NATS Streaming cluster ID")
+	flag.StringVar(&clusterID, "cluster", "test-cluster", "The NATS Streaming cluster ID")
+	flag.StringVar(&clientID, "id", "", "The NATS Streaming client ID to connect with")
+	flag.StringVar(&clientID, "clientid", "", "The NATS Streaming client ID to connect with")
+	flag.BoolVar(&showTime, "t", false, "Display timestamps")
+	// Subscription options
+	flag.Uint64Var(&startSeq, "seq", 0, "Start at sequence no.")
+	flag.BoolVar(&deliverAll, "all", false, "Deliver all")
+	flag.BoolVar(&deliverLast, "last", false, "Start with last value")
+	flag.StringVar(&startDelta, "since", "", "Deliver messages since specified time offset")
+	flag.StringVar(&durable, "durable", "", "Durable subscriber name")
+	flag.StringVar(&qgroup, "qgroup", "", "Queue group name")
+	flag.BoolVar(&unsubscribe, "unsubscribe", false, "Unsubscribe the durable on exit")
+
+	log.SetFlags(0)
+	flag.Usage = usage
+	flag.Parse()
+
+	args := flag.Args()
+
+	if clientID == "" {
+		log.Printf("Error: A unique client ID must be specified.")
+		usage()
+	}
+	if len(args) < 1 {
+		log.Printf("Error: A subject must be specified.")
+		usage()
+	}
+
+	sc, err := stan.Connect(clusterID, clientID, stan.NatsURL(URL),
+		stan.SetConnectionLostHandler(func(_ stan.Conn, reason error) {
+			log.Fatalf("Connection lost, reason: %v", reason)
+		}))
+	if err != nil {
+		log.Fatalf("Can't connect: %v.\nMake sure a NATS Streaming Server is running at: %s", err, URL)
+	}
+	log.Printf("Connected to %s clusterID: [%s] clientID: [%s]\n", URL, clusterID, clientID)
+
+	subj, i := args[0], 0
+
+	mcb := func(msg *stan.Msg) {
+		i++
+		printMsg(msg, i)
+	}
+
+	startOpt := stan.StartAt(pb.StartPosition_NewOnly)
+
+	if startSeq != 0 {
+		startOpt = stan.StartAtSequence(startSeq)
+	} else if deliverLast {
+		startOpt = stan.StartWithLastReceived()
+	} else if deliverAll {
+		log.Print("subscribing with DeliverAllAvailable")
+		startOpt = stan.DeliverAllAvailable()
+	} else if startDelta != "" {
+		ago, err := time.ParseDuration(startDelta)
+		if err != nil {
+			sc.Close()
+			log.Fatal(err)
+		}
+		startOpt = stan.StartAtTimeDelta(ago)
+	}
+
+	sub, err := sc.QueueSubscribe(subj, qgroup, mcb, startOpt, stan.DurableName(durable))
+	if err != nil {
+		sc.Close()
+		log.Fatal(err)
+	}
+
+	log.Printf("Listening on [%s], clientID=[%s], qgroup=[%s] durable=[%s]\n", subj, clientID, qgroup, durable)
+
+	if showTime {
+		log.SetFlags(log.LstdFlags)
+	}
+
+	// Wait for a SIGINT (perhaps triggered by user with CTRL-C)
+	// Run cleanup when signal is received
+	signalChan := make(chan os.Signal, 1)
+	cleanupDone := make(chan bool)
+	signal.Notify(signalChan, os.Interrupt)
+	go func() {
+		for range signalChan {
+			fmt.Printf("\nReceived an interrupt, unsubscribing and closing connection...\n\n")
+			// Do not unsubscribe a durable on exit, except if asked to.
+			if durable == "" || unsubscribe {
+				sub.Unsubscribe()
+			}
+			sc.Close()
+			cleanupDone <- true
+		}
+	}()
+	<-cleanupDone
+}