fix(kafka): update kafka lib; make kafka errors unsilent

services/kafka/config.go

@@ -2,12 +2,13 @@ package kafka
 
 import (
 	"crypto/tls"
+	"fmt"
 	"time"
 
 	"github.com/influxdata/influxdb/toml"
 	"github.com/influxdata/kapacitor/tlsconfig"
 	"github.com/pkg/errors"
-	kafka "github.com/segmentio/kafka-go"
+	"github.com/segmentio/kafka-go"
 )
 
 const (
@@ -75,7 +76,7 @@ func (c *Config) ApplyConditionalDefaults() {
 	}
 }
 
-func (c Config) WriterConfig() (kafka.WriterConfig, error) {
+func (c Config) WriterConfig(diagnostic Diagnostic) (kafka.WriterConfig, error) {
 	var tlsCfg *tls.Config
 	if c.UseSSL {
 		t, err := tlsconfig.Create(c.SSLCA, c.SSLCert, c.SSLKey, c.InsecureSkipVerify)
@@ -88,6 +89,7 @@ func (c Config) WriterConfig() (kafka.WriterConfig, error) {
 		Timeout: time.Duration(c.Timeout),
 		TLS:     tlsCfg,
 	}
+
 	return kafka.WriterConfig{
 		Brokers:      c.Brokers,
 		Balancer:     &kafka.LeastBytes{},
@@ -100,6 +102,9 @@ func (c Config) WriterConfig() (kafka.WriterConfig, error) {
 		// It also means that no errors will be captured from the WriteMessages method.
 		// As such we track the WriteStats for errors and report them with Kapacitor's normal diagnostics.
 		Async: true,
+		ErrorLogger: kafka.LoggerFunc(func(s string, x ...interface{}) {
+			diagnostic.Error("kafka client error", fmt.Errorf(s, x...))
+		}),
 	}, nil
 }
 

services/kafka/service.go

@@ -127,8 +127,8 @@ func NewCluster(c Config) *Cluster {
 	}
 }
 
-func (c *Cluster) WriteMessage(topic string, key, msg []byte) error {
-	w, err := c.writer(topic)
+func (c *Cluster) WriteMessage(diagnostic Diagnostic, topic string, key, msg []byte) error {
+	w, err := c.writer(topic, diagnostic)
 	if err != nil {
 		return err
 	}
@@ -138,7 +138,7 @@ func (c *Cluster) WriteMessage(topic string, key, msg []byte) error {
 	})
 }
 
-func (c *Cluster) writer(topic string) (*writer, error) {
+func (c *Cluster) writer(topic string, diagnostic Diagnostic) (*writer, error) {
 	c.mu.RLock()
 	w, ok := c.writers[topic]
 	c.mu.RUnlock()
@@ -147,10 +147,13 @@ func (c *Cluster) writer(topic string) (*writer, error) {
 		defer c.mu.Unlock()
 		w, ok = c.writers[topic]
 		if !ok {
-			wc, err := c.cfg.WriterConfig()
+			wc, err := c.cfg.WriterConfig(diagnostic)
 			if err != nil {
 				return nil, err
 			}
+			if topic == "" {
+				return nil, errors.New("topic must not be empty")
+			}
 			wc.Topic = topic
 			kw := kafka.NewWriter(wc)
 			// Create new writer
@@ -315,7 +318,7 @@ func (s *Service) Test(options interface{}) error {
 	if !ok {
 		return fmt.Errorf("unknown cluster %q", o.Cluster)
 	}
-	return c.WriteMessage(o.Topic, []byte(o.Key), []byte(o.Message))
+	return c.WriteMessage(s.diag, o.Topic, []byte(o.Key), []byte(o.Message))
 }
 
 type HandlerConfig struct {
@@ -347,12 +350,15 @@ func (s *Service) Handler(c HandlerConfig, ctx ...keyvalue.T) (alert.Handler, er
 			return nil, errors.Wrap(err, "failed to parse template")
 		}
 	}
+
+	diag := s.diag.WithContext(ctx...)
+
 	return &handler{
 		s:        s,
 		cluster:  cluster,
 		topic:    c.Topic,
 		template: t,
-		diag:     s.diag.WithContext(ctx...),
+		diag:     diag,
 	}, nil
 }
 
@@ -361,7 +367,7 @@ func (h *handler) Handle(event alert.Event) {
 	if err != nil {
 		h.diag.Error("failed to prepare kafka message body", err)
 	}
-	if err := h.cluster.WriteMessage(h.topic, []byte(event.State.ID), body); err != nil {
+	if err := h.cluster.WriteMessage(h.diag, h.topic, []byte(event.State.ID), body); err != nil {
 		h.diag.Error("failed to write message to kafka", err)
 	}
 }