func (s *Server) withAccessLog(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
started := time.Now()
next.ServeHTTP(w, r)
entry := &accessLogEntry{
Method: r.Method,
Host: r.Host,
Path: r.RequestURI,
IP: r.RemoteAddr,
ResponseTime: float64(time.Since(started)) / float64(time.Second),
}
// We will use the client's IP address as key. This will cause
// all the access log entries of the same IP address to end up
// on the same partition.
s.AccessLogProducer.Input() <- &sarama.ProducerMessage{
Topic: "access_log",
Key: sarama.StringEncoder(r.RemoteAddr),
Value: entry,
}
})
}
func (s *Server) collectQueryStringData() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
// We are not setting a message key, which means that all messages will
// be distributed randomly over the different partitions.
partition, offset, err := s.DataCollector.SendMessage(&sarama.ProducerMessage{
Topic: "important",
Value: sarama.StringEncoder(r.URL.RawQuery),
})
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
fmt.Fprintf(w, "Failed to store your data:, %s", err)
} else {
// The tuple (topic, partition, offset) can be used as a unique identifier
// for a message in a Kafka cluster.
fmt.Fprintf(w, "Your data is stored with unique identifier important/%d/%d", partition, offset)
}
})
}
func main() {
flag.Parse()
if *brokerList == "" {
printUsageErrorAndExit("no -brokers specified. Alternatively, set the KAFKA_PEERS environment variable")
}
if *topic == "" {
printUsageErrorAndExit("no -topic specified")
}
if *verbose {
sarama.Logger = logger
}
config := sarama.NewConfig()
config.Producer.RequiredAcks = sarama.WaitForAll
switch *partitioner {
case "":
if *partition >= 0 {
config.Producer.Partitioner = sarama.NewManualPartitioner
} else {
config.Producer.Partitioner = sarama.NewHashPartitioner
}
case "hash":
config.Producer.Partitioner = sarama.NewHashPartitioner
case "random":
config.Producer.Partitioner = sarama.NewRandomPartitioner
case "manual":
config.Producer.Partitioner = sarama.NewManualPartitioner
if *partition == -1 {
printUsageErrorAndExit("-partition is required when partitioning manually")
}
default:
printUsageErrorAndExit(fmt.Sprintf("Partitioner %s not supported.", *partitioner))
}
message := &sarama.ProducerMessage{Topic: *topic, Partition: int32(*partition)}
if *key != "" {
message.Key = sarama.StringEncoder(*key)
}
if *value != "" {
message.Value = sarama.StringEncoder(*value)
} else if stdinAvailable() {
bytes, err := ioutil.ReadAll(os.Stdin)
if err != nil {
printErrorAndExit(66, "Failed to read data from the standard input: %s", err)
}
message.Value = sarama.ByteEncoder(bytes)
} else {
printUsageErrorAndExit("-value is required, or you have to provide the value on stdin")
}
producer, err := sarama.NewSyncProducer(strings.Split(*brokerList, ","), config)
if err != nil {
printErrorAndExit(69, "Failed to open Kafka producer: %s", err)
}
defer func() {
if err := producer.Close(); err != nil {
logger.Println("Failed to close Kafka producer cleanly:", err)
}
}()
partition, offset, err := producer.SendMessage(message)
if err != nil {
printErrorAndExit(69, "Failed to produce message: %s", err)
} else if !*silent {
fmt.Printf("topic=%s\tpartition=%d\toffset=%d\n", *topic, partition, offset)
}
}