Merge pull request #303 from carillonator/krbclient-nil-check

Check for nil krbClient with GSSAPI

Author: sbocinec

docs/reference-config.yaml

@@ -50,6 +50,7 @@ kafka:
     mechanism: "PLAIN"
     # GSSAPI / Kerberos config properties
     gssapi:
+      # Required. One of USER_AUTH or KEYTAB_AUTH
       authType: ""
       keyTabPath: ""
       kerberosConfigPath: ""

kafka/client_config_helper.go

@@ -107,6 +107,9 @@ func NewKgoConfig(cfg Config, logger *zap.Logger) ([]kgo.Opt, error) {
 					kerbCfg,
 					client.DisablePAFXFAST(!cfg.SASL.GSSAPI.EnableFast))
 			}
+			if krbClient == nil {
+				return nil, fmt.Errorf("kafka.sasl.gssapi.authType must be one of USER_AUTH or KEYTAB_AUTH")
+			}
 			kerberosMechanism := kerberos.Auth{
 				Client:           krbClient,
 				Service:          cfg.SASL.GSSAPI.ServiceName,