func main() {
flag.Parse()
if *brokerList == "" {
printUsageErrorAndExit("You have to provide -brokers as a comma-separated list, or set the KAFKA_PEERS environment variable.")
}
if *topic == "" {
printUsageErrorAndExit("-topic is required")
}
if *partition == -1 {
printUsageErrorAndExit("-partition is required")
}
if *verbose {
sarama.Logger = logger
}
var (
initialOffset int64
offsetError error
)
switch *offset {
case "oldest":
initialOffset = sarama.OffsetOldest
case "newest":
initialOffset = sarama.OffsetNewest
default:
initialOffset, offsetError = strconv.ParseInt(*offset, 10, 64)
}
if offsetError != nil {
printUsageErrorAndExit("Invalid initial offset: %s", *offset)
}
c, err := sarama.NewConsumer(strings.Split(*brokerList, ","), nil)
if err != nil {
printErrorAndExit(69, "Failed to start consumer: %s", err)
}
pc, err := c.ConsumePartition(*topic, int32(*partition), initialOffset)
if err != nil {
printErrorAndExit(69, "Failed to start partition consumer: %s", err)
}
go func() {
signals := make(chan os.Signal, 1)
signal.Notify(signals, os.Kill, os.Interrupt)
<-signals
pc.AsyncClose()
}()
for msg := range pc.Messages() {
fmt.Printf("Offset:\t%d\n", msg.Offset)
fmt.Printf("Key:\t%s\n", string(msg.Key))
fmt.Printf("Value:\t%s\n", string(msg.Value))
fmt.Println()
}
if err := c.Close(); err != nil {
logger.Println("Failed to close consumer: ", err)
}
}
func main() {
flag.Parse()
if *brokerList == "" {
printUsageErrorAndExit("You have to provide -brokers as a comma-separated list, or set the KAFKA_PEERS environment variable.")
}
if *topic == "" {
printUsageErrorAndExit("-topic is required")
}
if *verbose {
sarama.Logger = logger
}
var initialOffset int64
switch *offset {
case "oldest":
initialOffset = sarama.OffsetOldest
case "newest":
initialOffset = sarama.OffsetNewest
default:
printUsageErrorAndExit("-offset should be `oldest` or `newest`")
}
c, err := sarama.NewConsumer(strings.Split(*brokerList, ","), nil)
if err != nil {
printErrorAndExit(69, "Failed to start consumer: %s", err)
}
partitionList, err := getPartitions(c)
if err != nil {
printErrorAndExit(69, "Failed to get the list of partitions: %s", err)
}
var (
messages = make(chan *sarama.ConsumerMessage, *bufferSize)
closing = make(chan struct{})
wg sync.WaitGroup
)
go func() {
signals := make(chan os.Signal, 1)
signal.Notify(signals, os.Kill, os.Interrupt)
<-signals
logger.Println("Initiating shutdown of consumer...")
close(closing)
}()
for _, partition := range partitionList {
pc, err := c.ConsumePartition(*topic, partition, initialOffset)
if err != nil {
printErrorAndExit(69, "Failed to start consumer for partition %d: %s", partition, err)
}
go func(pc sarama.PartitionConsumer) {
<-closing
pc.AsyncClose()
}(pc)
wg.Add(1)
go func(pc sarama.PartitionConsumer) {
defer wg.Done()
for message := range pc.Messages() {
messages <- message
}
}(pc)
}
go func() {
for msg := range messages {
fmt.Printf("Partition:\t%d\n", msg.Partition)
fmt.Printf("Offset:\t%d\n", msg.Offset)
fmt.Printf("Key:\t%s\n", string(msg.Key))
fmt.Printf("Value:\t%s\n", string(msg.Value))
fmt.Println()
}
}()
wg.Wait()
logger.Println("Done consuming topic", *topic)
close(messages)
if err := c.Close(); err != nil {
logger.Println("Failed to close consumer: ", err)
}
}