package kafka import ( "crypto/tls" "fmt" "log" "strings" "github.com/Shopify/sarama" "github.com/gofrs/uuid" "github.com/influxdata/telegraf" tlsint "github.com/influxdata/telegraf/internal/tls" "github.com/influxdata/telegraf/plugins/outputs" "github.com/influxdata/telegraf/plugins/serializers" ) var ValidTopicSuffixMethods = []string{ "", "measurement", "tags", } type ( Kafka struct { Brokers []string Topic string ClientID string `toml:"client_id"` TopicSuffix TopicSuffix `toml:"topic_suffix"` RoutingTag string `toml:"routing_tag"` RoutingKey string `toml:"routing_key"` CompressionCodec int RequiredAcks int MaxRetry int MaxMessageBytes int `toml:"max_message_bytes"` Version string `toml:"version"` // Legacy TLS config options // TLS client certificate Certificate string // TLS client key Key string // TLS certificate authority CA string tlsint.ClientConfig // SASL Username SASLUsername string `toml:"sasl_username"` // SASL Password SASLPassword string `toml:"sasl_password"` tlsConfig tls.Config producer sarama.SyncProducer serializer serializers.Serializer } TopicSuffix struct { Method string `toml:"method"` Keys []string `toml:"keys"` Separator string `toml:"separator"` } ) // DebugLogger logs messages from sarama at the debug level. type DebugLogger struct { } func (*DebugLogger) Print(v ...interface{}) { args := make([]interface{}, 0, len(v)+1) args = append(args, "D! [sarama] ") log.Print(v...) } func (*DebugLogger) Printf(format string, v ...interface{}) { log.Printf("D! [sarama] "+format, v...) } func (*DebugLogger) Println(v ...interface{}) { args := make([]interface{}, 0, len(v)+1) args = append(args, "D! [sarama] ") log.Println(args...) } var sampleConfig = ` ## URLs of kafka brokers brokers = ["localhost:9092"] ## Kafka topic for producer messages topic = "telegraf" ## Optional Client id # client_id = "Telegraf" ## Set the minimal supported Kafka version. Setting this enables the use of new ## Kafka features and APIs. Of particular interest, lz4 compression ## requires at least version 0.10.0.0. ## ex: version = "1.1.0" # version = "" ## Optional topic suffix configuration. ## If the section is omitted, no suffix is used. ## Following topic suffix methods are supported: ## measurement - suffix equals to separator + measurement's name ## tags - suffix equals to separator + specified tags' values ## interleaved with separator ## Suffix equals to "_" + measurement name # [outputs.kafka.topic_suffix] # method = "measurement" # separator = "_" ## Suffix equals to "__" + measurement's "foo" tag value. ## If there's no such a tag, suffix equals to an empty string # [outputs.kafka.topic_suffix] # method = "tags" # keys = ["foo"] # separator = "__" ## Suffix equals to "_" + measurement's "foo" and "bar" ## tag values, separated by "_". If there is no such tags, ## their values treated as empty strings. # [outputs.kafka.topic_suffix] # method = "tags" # keys = ["foo", "bar"] # separator = "_" ## Telegraf tag to use as a routing key ## ie, if this tag exists, its value will be used as the routing key routing_tag = "host" ## Static routing key. Used when no routing_tag is set or as a fallback ## when the tag specified in routing tag is not found. If set to "random", ## a random value will be generated for each message. ## ex: routing_key = "random" ## routing_key = "telegraf" # routing_key = "" ## CompressionCodec represents the various compression codecs recognized by ## Kafka in messages. ## 0 : No compression ## 1 : Gzip compression ## 2 : Snappy compression ## 3 : LZ4 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 maximum number of times to retry sending a metric before failing ## until the next flush. # max_retry = 3 ## The maximum permitted size of a message. Should be set equal to or ## smaller than the broker's 'message.max.bytes'. # max_message_bytes = 1000000 ## Optional TLS Config # tls_ca = "/etc/telegraf/ca.pem" # tls_cert = "/etc/telegraf/cert.pem" # tls_key = "/etc/telegraf/key.pem" ## Use TLS but skip chain & host verification # insecure_skip_verify = false ## Optional SASL Config # sasl_username = "kafka" # sasl_password = "secret" ## Data format to output. ## Each data format has its 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 ValidateTopicSuffixMethod(method string) error { for _, validMethod := range ValidTopicSuffixMethods { if method == validMethod { return nil } } return fmt.Errorf("Unknown topic suffix method provided: %s", method) } func (k *Kafka) GetTopicName(metric telegraf.Metric) string { var topicName string switch k.TopicSuffix.Method { case "measurement": topicName = k.Topic + k.TopicSuffix.Separator + metric.Name() case "tags": var topicNameComponents []string topicNameComponents = append(topicNameComponents, k.Topic) for _, tag := range k.TopicSuffix.Keys { tagValue := metric.Tags()[tag] if tagValue != "" { topicNameComponents = append(topicNameComponents, tagValue) } } topicName = strings.Join(topicNameComponents, k.TopicSuffix.Separator) default: topicName = k.Topic } return topicName } func (k *Kafka) SetSerializer(serializer serializers.Serializer) { k.serializer = serializer } func (k *Kafka) Connect() error { err := ValidateTopicSuffixMethod(k.TopicSuffix.Method) if err != nil { return err } config := sarama.NewConfig() if k.Version != "" { version, err := sarama.ParseKafkaVersion(k.Version) if err != nil { return err } config.Version = version } if k.ClientID != "" { config.ClientID = k.ClientID } else { config.ClientID = "Telegraf" } config.Producer.RequiredAcks = sarama.RequiredAcks(k.RequiredAcks) config.Producer.Compression = sarama.CompressionCodec(k.CompressionCodec) config.Producer.Retry.Max = k.MaxRetry config.Producer.Return.Successes = true if k.MaxMessageBytes > 0 { config.Producer.MaxMessageBytes = k.MaxMessageBytes } // Legacy support ssl config if k.Certificate != "" { k.TLSCert = k.Certificate k.TLSCA = k.CA k.TLSKey = k.Key } tlsConfig, err := k.ClientConfig.TLSConfig() if err != nil { return err } if tlsConfig != nil { config.Net.TLS.Config = tlsConfig config.Net.TLS.Enable = true } if k.SASLUsername != "" && k.SASLPassword != "" { config.Net.SASL.User = k.SASLUsername config.Net.SASL.Password = k.SASLPassword config.Net.SASL.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) routingKey(metric telegraf.Metric) (string, error) { if k.RoutingTag != "" { key, ok := metric.GetTag(k.RoutingTag) if ok { return key, nil } } if k.RoutingKey == "random" { u, err := uuid.NewV4() if err != nil { return "", err } return u.String(), nil } return k.RoutingKey, nil } func (k *Kafka) Write(metrics []telegraf.Metric) error { msgs := make([]*sarama.ProducerMessage, 0, len(metrics)) for _, metric := range metrics { buf, err := k.serializer.Serialize(metric) if err != nil { log.Printf("D! [outputs.kafka] Could not serialize metric: %v", err) continue } m := &sarama.ProducerMessage{ Topic: k.GetTopicName(metric), Value: sarama.ByteEncoder(buf), } key, err := k.routingKey(metric) if err != nil { return fmt.Errorf("could not generate routing key: %v", err) } if key != "" { m.Key = sarama.StringEncoder(key) } msgs = append(msgs, m) } err := k.producer.SendMessages(msgs) if err != nil { // We could have many errors, return only the first encountered. if errs, ok := err.(sarama.ProducerErrors); ok { for _, prodErr := range errs { if prodErr.Err == sarama.ErrMessageSizeTooLarge { log.Printf("E! Error writing to output [kafka]: Message too large, consider increasing `max_message_bytes`; dropping batch") return nil } return prodErr } } return err } return nil } func init() { sarama.Logger = &DebugLogger{} outputs.Add("kafka", func() telegraf.Output { return &Kafka{ MaxRetry: 3, RequiredAcks: -1, } }) }