/
nsq_tail.go
140 lines (114 loc) · 3.51 KB
/
nsq_tail.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
package main
import (
"flag"
"fmt"
"log"
"math/rand"
"os"
"os/signal"
"syscall"
"time"
"github.com/nsqio/go-nsq"
"github.com/nsqio/nsq/internal/app"
"github.com/nsqio/nsq/internal/version"
)
var (
showVersion = flag.Bool("version", false, "print version string")
channel = flag.String("channel", "", "NSQ channel")
maxInFlight = flag.Int("max-in-flight", 200, "max number of messages to allow in flight")
totalMessages = flag.Int("n", 0, "total messages to show (will wait if starved)")
printTopic = flag.Bool("print-topic", false, "print topic name where message was received")
nsqdTCPAddrs = app.StringArray{}
lookupdHTTPAddrs = app.StringArray{}
topics = app.StringArray{}
)
func init() {
flag.Var(&nsqdTCPAddrs, "nsqd-tcp-address", "nsqd TCP address (may be given multiple times)")
flag.Var(&lookupdHTTPAddrs, "lookupd-http-address", "lookupd HTTP address (may be given multiple times)")
flag.Var(&topics, "topic", "NSQ topic (may be given multiple times)")
}
type TailHandler struct {
topicName string
totalMessages int
messagesShown int
}
func (th *TailHandler) HandleMessage(m *nsq.Message) error {
th.messagesShown++
if *printTopic {
_, err := os.Stdout.WriteString(th.topicName)
if err != nil {
log.Fatalf("ERROR: failed to write to os.Stdout - %s", err)
}
_, err = os.Stdout.WriteString(" | ")
if err != nil {
log.Fatalf("ERROR: failed to write to os.Stdout - %s", err)
}
}
_, err := os.Stdout.Write(m.Body)
if err != nil {
log.Fatalf("ERROR: failed to write to os.Stdout - %s", err)
}
_, err = os.Stdout.WriteString("\n")
if err != nil {
log.Fatalf("ERROR: failed to write to os.Stdout - %s", err)
}
if th.totalMessages > 0 && th.messagesShown >= th.totalMessages {
os.Exit(0)
}
return nil
}
func main() {
cfg := nsq.NewConfig()
flag.Var(&nsq.ConfigFlag{cfg}, "consumer-opt", "option to passthrough to nsq.Consumer (may be given multiple times, http://godoc.org/github.com/nsqio/go-nsq#Config)")
flag.Parse()
if *showVersion {
fmt.Printf("nsq_tail v%s\n", version.Binary)
return
}
if *channel == "" {
rand.Seed(time.Now().UnixNano())
*channel = fmt.Sprintf("tail%06d#ephemeral", rand.Int()%999999)
}
if len(nsqdTCPAddrs) == 0 && len(lookupdHTTPAddrs) == 0 {
log.Fatal("--nsqd-tcp-address or --lookupd-http-address required")
}
if len(nsqdTCPAddrs) > 0 && len(lookupdHTTPAddrs) > 0 {
log.Fatal("use --nsqd-tcp-address or --lookupd-http-address not both")
}
if len(topics) == 0 {
log.Fatal("--topic required")
}
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
// Don't ask for more messages than we want
if *totalMessages > 0 && *totalMessages < *maxInFlight {
*maxInFlight = *totalMessages
}
cfg.UserAgent = fmt.Sprintf("nsq_tail/%s go-nsq/%s", version.Binary, nsq.VERSION)
cfg.MaxInFlight = *maxInFlight
consumers := []*nsq.Consumer{}
for i := 0; i < len(topics); i += 1 {
log.Printf("Adding consumer for topic: %s\n", topics[i])
consumer, err := nsq.NewConsumer(topics[i], *channel, cfg)
if err != nil {
log.Fatal(err)
}
consumer.AddHandler(&TailHandler{topicName: topics[i], totalMessages: *totalMessages})
err = consumer.ConnectToNSQDs(nsqdTCPAddrs)
if err != nil {
log.Fatal(err)
}
err = consumer.ConnectToNSQLookupds(lookupdHTTPAddrs)
if err != nil {
log.Fatal(err)
}
consumers = append(consumers, consumer)
}
<-sigChan
for _, consumer := range consumers {
consumer.Stop()
}
for _, consumer := range consumers {
<-consumer.StopChan
}
}