telegraf/plugins/outputs/kafka/kafka.go

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package kafka
import (
"crypto/tls"
"fmt"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/plugins/outputs"
"github.com/influxdata/telegraf/plugins/serializers"
"github.com/Shopify/sarama"
)
type Kafka struct {
// Kafka brokers to send metrics to
Brokers []string
// Kafka topic
Topic string
// Routing Key Tag
RoutingTag string `toml:"routing_tag"`
// Compression Codec Tag
CompressionCodec int
// RequiredAcks Tag
RequiredAcks int
// MaxRetry Tag
MaxRetry int
// Legacy SSL config options
// TLS client certificate
Certificate string
// TLS client key
Key string
// TLS certificate authority
CA string
// Path to CA file
SSLCA string `toml:"ssl_ca"`
// Path to host cert file
SSLCert string `toml:"ssl_cert"`
// Path to cert key file
SSLKey string `toml:"ssl_key"`
// Skip SSL verification
InsecureSkipVerify bool
tlsConfig tls.Config
producer sarama.SyncProducer
serializer serializers.Serializer
}
var sampleConfig = `
## URLs of kafka brokers
brokers = ["localhost:9092"]
## Kafka topic for producer messages
topic = "telegraf"
## Telegraf tag to use as a routing key
## ie, if this tag exists, it's value will be used as the routing key
routing_tag = "host"
## CompressionCodec represents the various compression codecs recognized by
## Kafka in messages.
## 0 : No compression
## 1 : Gzip compression
## 2 : Snappy compression
compression_codec = 0
## RequiredAcks is used in Produce Requests to tell the broker how many
## replica acknowledgements it must see before responding
## 0 : the producer never waits for an acknowledgement from the broker.
## This option provides the lowest latency but the weakest durability
## guarantees (some data will be lost when a server fails).
## 1 : the producer gets an acknowledgement after the leader replica has
## received the data. This option provides better durability as the
## client waits until the server acknowledges the request as successful
## (only messages that were written to the now-dead leader but not yet
## replicated will be lost).
## -1: the producer gets an acknowledgement after all in-sync replicas have
## received the data. This option provides the best durability, we
## guarantee that no messages will be lost as long as at least one in
## sync replica remains.
required_acks = -1
## The total number of times to retry sending a message
max_retry = 3
## Optional SSL Config
# ssl_ca = "/etc/telegraf/ca.pem"
# ssl_cert = "/etc/telegraf/cert.pem"
# ssl_key = "/etc/telegraf/key.pem"
## Use SSL but skip chain & host verification
# insecure_skip_verify = false
## Data format to output.
## Each data format has it's own unique set of configuration options, read
## more about them here:
## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md
data_format = "influx"
`
func (k *Kafka) SetSerializer(serializer serializers.Serializer) {
k.serializer = serializer
}
func (k *Kafka) Connect() error {
config := sarama.NewConfig()
config.Producer.RequiredAcks = sarama.RequiredAcks(k.RequiredAcks)
config.Producer.Compression = sarama.CompressionCodec(k.CompressionCodec)
config.Producer.Retry.Max = k.MaxRetry
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config.Producer.Return.Successes = true
// Legacy support ssl config
if k.Certificate != "" {
k.SSLCert = k.Certificate
k.SSLCA = k.CA
k.SSLKey = k.Key
}
tlsConfig, err := internal.GetTLSConfig(
k.SSLCert, k.SSLKey, k.SSLCA, k.InsecureSkipVerify)
if err != nil {
return err
}
if tlsConfig != nil {
config.Net.TLS.Config = tlsConfig
config.Net.TLS.Enable = true
}
producer, err := sarama.NewSyncProducer(k.Brokers, config)
if err != nil {
return err
}
k.producer = producer
return nil
}
func (k *Kafka) Close() error {
return k.producer.Close()
}
func (k *Kafka) SampleConfig() string {
return sampleConfig
}
func (k *Kafka) Description() string {
return "Configuration for the Kafka server to send metrics to"
}
func (k *Kafka) Write(metrics []telegraf.Metric) error {
if len(metrics) == 0 {
return nil
}
for _, metric := range metrics {
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buf, err := k.serializer.Serialize(metric)
if err != nil {
return err
}
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m := &sarama.ProducerMessage{
Topic: k.Topic,
Value: sarama.ByteEncoder(buf),
}
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if h, ok := metric.Tags()[k.RoutingTag]; ok {
m.Key = sarama.StringEncoder(h)
}
_, _, err = k.producer.SendMessage(m)
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if err != nil {
return fmt.Errorf("FAILED to send kafka message: %s\n", err)
}
}
return nil
}
func init() {
outputs.Add("kafka", func() telegraf.Output {
return &Kafka{
MaxRetry: 3,
RequiredAcks: -1,
}
})
}