com.microsoft.azure.functions.annotation

Annotation Type KafkaTrigger

@Target(value=PARAMETER)
 @Retention(value=RUNTIME)
public @interface KafkaTrigger

Place this on a parameter whose value would come from Kafka, and causing the method to run when Kafka event is consumed. The parameter type can be one of the following:

• Any native Java types such as int, String, byte[]
• Nullable values using Optional<T>
• Any POJO type, currently supported only for Cardinality.One

The following example shows a Java function that is invoked when messages are consumed with the specified topic, brokerList, and consumerGroup on a Kafka cluster.

  @FunctionName("KafkaTrigger-Java")
 public void run(
     @KafkaTrigger(name = "kafkaTrigger",
                      topic = "users", 
                      brokerList="broker:29092",
                      consumerGroup="functions")
                      List<Map<String, String>> kafkaEventData,
     final ExecutionContext context
 ) {
     context.getLogger().info(kafkaEventData);
 }
 

Since:

1.4.0

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String	brokerList Defines the BrokerList.
String	consumerGroup Defines the consumer group.
String	name The variable name used in function code for the request or request body.
String	topic Defines the Topic.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
com.microsoft.azure.functions.BrokerAuthenticationMode	authenticationMode SASL mechanism to use for authentication.
String	avroSchema Avro schema for generic record deserialization default ""
Cardinality	cardinality Cardinality of the trigger input.
String	dataType Defines how Functions runtime should treat the parameter value.
String	eventHubConnectionString Defines the EventHub connection string when using KafkaOutput protocol header feature of Azure EventHubs.
String	password SASL password with the PLAIN and SASL-SCRAM-..
com.microsoft.azure.functions.BrokerProtocol	protocol Defines the security protocol used to communicate with brokers default is NOTSET
String	sslCaLocation Path to CA certificate file for verifying the broker's certificate.
String	sslCertificateLocation Path to client's certificate.
String	sslKeyLocation Path to client's private key (PEM) used for authentication.
String	sslKeyPassword Password for client's certificate.
String	username SASL username with the PLAIN and SASL-SCRAM-..

Element Detail

name

public abstract String name

The variable name used in function code for the request or request body.

Returns:

The variable name used in function code for the request or request body.

topic

public abstract String topic

Defines the Topic.

Returns:

The topic.

brokerList

public abstract String brokerList

Defines the BrokerList.

Returns:

The brokerList.

consumerGroup

public abstract String consumerGroup

Defines the consumer group.

Returns:

The consumer group.

eventHubConnectionString

public abstract String eventHubConnectionString

Defines the EventHub connection string when using KafkaOutput protocol header feature of Azure EventHubs.

Returns:

The EventHub connection string.

Default:

""

cardinality

public abstract Cardinality cardinality

Cardinality of the trigger input. Choose 'One' if the input is a single message or 'Many' if the input is an array of messages. If you choose 'Many', please set a dataType. Default: 'One'

Returns:

The cardinality.

Default:

com.microsoft.azure.functions.annotation.Cardinality.ONE

dataType

public abstract String dataType

Defines how Functions runtime should treat the parameter value. Possible values are:

• "": get the value as a string, and try to deserialize to actual parameter type like POJO
• string: always get the value as a string
• binary: get the value as a binary data, and try to deserialize to actual parameter type byte[]

Returns:

The dataType which will be used by the Functions runtime.

Default:

""

authenticationMode

public abstract com.microsoft.azure.functions.BrokerAuthenticationMode authenticationMode

SASL mechanism to use for authentication. Allowed values: Gssapi, Plain, ScramSha256, ScramSha512 Default: NOTSET

Returns:

The broker authentication mode.

Default:

com.microsoft.azure.functions.BrokerAuthenticationMode.NOTSET

username

public abstract String username

SASL username with the PLAIN and SASL-SCRAM-.. mechanisms Default: ""

Returns:

The SASL username.

Default:

""

password

public abstract String password

SASL password with the PLAIN and SASL-SCRAM-.. mechanisms Default: "" security.protocol in librdkafka

Returns:

The SASL password.

Default:

""

protocol

public abstract com.microsoft.azure.functions.BrokerProtocol protocol

Defines the security protocol used to communicate with brokers default is NOTSET

Returns:

The security protocol.

Default:

com.microsoft.azure.functions.BrokerProtocol.NOTSET

sslKeyLocation

public abstract String sslKeyLocation

Path to client's private key (PEM) used for authentication. Default "" ssl.key.location in librdkafka

Returns:

The ssl key location.

Default:

""

sslCaLocation

public abstract String sslCaLocation

Path to CA certificate file for verifying the broker's certificate. ssl.ca.location in librdkafka

Returns:

The path to CA certificate file.

Default:

""

sslCertificateLocation

public abstract String sslCertificateLocation

Path to client's certificate. ssl.certificate.location in librdkafka

Returns:

The ssl certificate location.

Default:

""

sslKeyPassword

public abstract String sslKeyPassword

Password for client's certificate. ssl.key.password in librdkafka

Returns:

The ssl key password.

Default:

""

avroSchema

public abstract String avroSchema

Avro schema for generic record deserialization default ""

Returns:

the avro schema

Default:

""