This Kafka sink connector for Amazon EventBridge allows you to send events (records) from one or multiple Kafka topic(s) to the specified event bus, including useful features such as:

• configurable topic to event detail-type name mapping
• custom IAM profiles per connector
• IAM role-based authentication
• support for dead-letter queues
• and schema registry support for Avro and Protocol Buffers (Protobuf).

See configuration below for details.

Amazon EventBridge event buses is a serverless event router that enables you to create scalable event-driven applications by routing events between your own applications, third-party SaaS applications, and other AWS services. You can set up routing rules to determine where to send your events, allowing for application architectures to react to changes in your systems as they occur. To get started with Amazon EventBridge, visit our documentation.

The connector is released as a community-supported open-source project with best effort support from the repository maintainers.

Two kafka-eventbridge-sink JAR files, are created on each release. The JAR file *-with-dependencies.jar contains all required dependencies of the connector, excluding Kafka Connect dependencies and (de)serializers, such as connect-api and connect-json. To support additional (de)serializers, such as Avro and Protobuf using the AWS Glue Schema Registry, install these dependencies in your Kafka Connect environment before deploying this connector.

The following steps describe how to clone the repo and perform a clean packaging of the connector. Requires Maven and Java Development Kit (JDK 11 or later).

Clone the repo:

git clone https://github.com/awslabs/eventbridge-kafka-connector.git
cd eventbridge-kafka-connector

Create JAR artifacts:

mvn clean package -Drevision=$(git describe --tags --always)

The following steps describe how to clone the repo and perform a clean packaging of the connector using Docker.

Clone the repo:

# clone repo
git clone https://github.com/awslabs/eventbridge-kafka-connector.git
cd eventbridge-kafka-connector

Create JAR artifacts:

docker run --rm -v $(pwd):/src -w /src -it maven:3-eclipse-temurin-11 \
mvn clean package -Drevision=$(git describe --tags --always)

In addition to the common Kafka Connect sink-related configuration options, this connector defines the following configuration properties.

The following minimal configuration configures the connector with default values, consuming Kafka records from the topic "json-values-topic" with record keys as String and JSON values (without schema), and sending events to the custom EventBridge event bus "kafkabus" in region "us-east-1".

{
    "name": "EventBridgeSink-Json",
    "config": {
        // consume from earliest record or last checkpointed offset if available
        "auto.offset.reset": "earliest",
        "connector.class": "software.amazon.event.kafkaconnector.EventBridgeSinkConnector",
        "topics": "json-values-topic",
        "aws.eventbridge.connector.id": "my-json-values-connector",
        "aws.eventbridge.eventbus.arn": "arn:aws:events:us-east-1:1234567890:event-bus/kafkabus",
        "aws.eventbridge.region": "us-east-1",
        "key.converter": "org.apache.kafka.connect.storage.StringConverter",
        // see note below on JSON schemas
        "value.converter": "org.apache.kafka.connect.json.JsonConverter",
        "value.converter.schemas.enable": false
    }
}

Continuing the example above, the following configuration defines a dead-letter queue (DLQ), i.e., topic, "json-dlq" which will be created with an replication factor of 1 if it does not exist. Records which cannot be converted or delivered to EventBridge will be sent to this DLQ.

{
    "name": "EventBridgeSink-Json",
    "config": {
        "auto.offset.reset": "earliest",
        "connector.class": "software.amazon.event.kafkaconnector.EventBridgeSinkConnector",
        "topics": "json-values-topic",
        "aws.eventbridge.connector.id": "my-json-values-connector",
        "aws.eventbridge.eventbus.arn": "arn:aws:events:us-east-1:1234567890:event-bus/kafkabus",
        "aws.eventbridge.region": "us-east-1",
        "key.converter": "org.apache.kafka.connect.storage.StringConverter",
        "value.converter": "org.apache.kafka.connect.json.JsonConverter",
        "value.converter.schemas.enable": false,
        "errors.tolerance":"all",
        "errors.deadletterqueue.topic.name":"json-dlq",
        "errors.deadletterqueue.topic.replication.factor":1
    }
}

The following configuration shows some advanced options, such as multiple topics with customized detail-type mapping, customized retry behavior, and IAM-based authentication, and how to deserialize Avro-encoded record values (with JSON-encoded keys) using AWS Glue Schema Registry (GSR).

{
  "name": "EventBridgeSink-Avro",
  "config": {
    "auto.offset.reset": "earliest",
    "connector.class": "software.amazon.event.kafkaconnector.EventBridgeSinkConnector",
    "topics": "avro-topic-1,avro-topic-2",
    "aws.eventbridge.connector.id": "avro-test-connector",
    "aws.eventbridge.eventbus.arn": "arn:aws:events:us-east-1:1234567890:event-bus/kafkabus",
    "aws.eventbridge.region": "us-east-1",
    // customized retries
    "aws.eventbridge.retries.max": 1,
    "aws.eventbridge.retries.delay": 1000,
    // custom detail-type mapping with topic suffix
    "aws.eventbridge.detail.types": "avro-test-${topic}",
    // IAM-based authentication
    "aws.eventbridge.iam.role.arn":"arn:aws:iam::1234567890:role/EventBridgePutEventsRole",
    "tasks.max": 1,
    "schema.history.internal.kafka.bootstrap.servers": "kafka:9092",
    "schema.history.internal.kafka.topic": "schema-changes.inventory",
    "key.converter": "org.apache.kafka.connect.json.JsonConverter",
    // dependencies (Classes) must be in the connector $CLASSPATH
    "value.converter": "com.amazonaws.services.schemaregistry.kafkaconnect.AWSKafkaAvroConverter",
    // GSR region
    "value.converter.region": "us-east-1",
    // GSR registry to use (expects schemas to exist and IAM role to have permission to read)
    "value.converter.registry.name": "avro-kafka-eventbridge",
    "value.converter.avroRecordType": "GENERIC_RECORD"
  }
}

The main task of this connector is to convert Kafka records to EventBridge events. Since this connector can be used to consume from multiple Kafka topics, which an EventBridge user might want to filter later on, the mapping of topic names to the EventBridge detail-type, i.e. event type, is customizable.

The default, i.e., when the configuration option aws.eventbridge.detail.types is not set, uses kafka-connect- as a prefix, followed by the topic name of each individual record. Alternatively, a custom detail-type can be defined per topic, provided as a comma-separated list with the syntax "<topic_name>:<detail_type>,<topic_name>:<detail_type>,..." e.g., "orders:com.example.org.orders.event.v0,customers:com.example.org.customers.event.v0". Records from the orders topic would result in EventBridge events with a detail-type: com.example.org.orders.event.v0.

If only the topic name should be used, a single expression with a dynamic ${topic} placeholder for all topics can be used e.g., "my-detail-type-${topic}" (using a hardcoded prefix), "${topic}" (only topic name), or as a static value without additional topic information "my-detail-type".

By default, the connector is configured to retry failed PutEvents API calls, i.e. an Exception was thrown, 2 times, i.e., 3 total attempts, with a constant delay between each retry of 200 milliseconds. These values can be configured (see configuration). The following exceptions (incl. their subclasses) are considered retryable: AwsServiceException, SdkClientException, ExecutionException, InterruptedException, TimeoutException.

Each connector task creates an EventBridge client using the AWS DefaultCredentialsProvider to look up credentials. AWS credential providers use a predefined configuration and configuration order to retrieve credentials from the various credential sources.

For example, you can provide (temporary) credentials to the connector using AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_SESSION_TOKEN environment variables. For information how to use AWS config and credentials profiles to resolve credentials, see Using different Configuration Profiles per Connector.

When the configuration property “aws.eventbridge.iam.role.arn” is set, the StsAssumeRoleCredentialsProvider is directly used to assume the specified IAM role and periodically refresh credentials with STS. The STS client uses the configured region of the connector for the STS client and retrieves credentials using the DefaultCredentialsProvider retrieval chain described above.

The connector only requires events:PutEvents permission as shown in the IAM policy example below. For details refer to the "Managing access permissions to your Amazon EventBridge resources" documentation.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowPutEventsKafkaConnector",
            "Effect": "Allow",
            "Action": "events:PutEvents",
            "Resource": "<ARN of your event bus>"
        }
    ]
}

If you run multiple EventBridge connectors in your Kafka Connect environment, using environment variables or Java system properties to configure your connectors means that each connector will be configured with the same IAM permissions. If you want to configure multiple connectors with specific (different) IAM profiles from your config and credentials files, the connector configuration option aws.eventbridge.iam.profile.name can be used.

With the connector configuration option aws.eventbridge.iam.profile.name you specify which profile the specific connector will use.

Steps to configure a connector with a configuration profile:

First, set "aws.eventbridge.iam.profile.name": "my-custom-profile" in the connector JSON configuration file (replace example values with your desired profile name). Then, create (or mount) the AWS config and credentials files in your Kafka Connect host(s). If the configuration files are not located/mounted in the default location, set the environment variables AWS_CONFIG_FILE and AWS_SHARED_CREDENTIALS_FILE accordingly. For example, with Docker you can mount them from your local machine using Docker volume mounts and environment variables (see example below).

config file:

[profile my-custom-profile]
output=text # not used by the SDK, for illustration purposes

credentials file:

[my-custom-profile]
aws_access_key_id=AKIAIOSFODNN7EXAMPLE
aws_secret_access_key=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
aws_session_token = IQoJb3JpZ2luX2IQoJb3JpZ2luX2IQoJb3JpZ2luX2IQoJb3JpZ2luX2IQoJb3JpZVERYLONGSTRINGEXAMPLE

Docker Compose file (snippet):

  connect:
    # (snip)
    environment:
      AWS_CONFIG_FILE: '/aws/config'
      AWS_SHARED_CREDENTIALS_FILE: '/aws/credentials'
    volumes:
      - /Users/example/.aws:/aws # mount credentials from local host to /aws folder

You can also use role-based authentication with this approach by referencing a source_profile in the config file:

config file (role-based authentication):

[profile my-custom-profile]
role_arn = arn:aws:iam::0123456789:role/KafkaConnectorPutEvents
source_profile = default # assume role using credentials using from the default profile specified in the credentials file

The connector can be deployed like any Kafka connector e.g., using the Kafka Connect REST API:

curl -i -X POST -H "Accept:application/json" -H  "Content-Type:application/json" http://<kafka-connect-api>:<kafka-connect-port>/connectors/ -d @connector_config.json

Below is an example of an event received by an EventBridge target using the minimal JSON configuration described above.

{
    // fields set by EventBridge
    "version": "0",
    "id": "dbc1c73a-c51d-0c0e-ca61-ab9278974c57",
    "account": "1234567890",
    "time": "2023-05-23T11:38:46Z",
    "region": "us-east-1",
    // customizable fields (see configuration)
    // detail-type is highly configurable (see section below)
    "detail-type": "kafka-connect-json-values-topic",
    // source is kafka-connect.<connector-id>
    "source": "kafka-connect.my-json-values-connector",
    "resources": [],
    // contains Kafka record key/value and metadata
    "detail": {
        "topic": "json-values-topic",
        "partition": 0,
        "offset": 0,
        "timestamp": 1684841916831,
        "timestampType": "CreateTime",
        "headers": [],
        "key": "order-1",
        "value": {
            "orderItems": [
                "item-1",
                "item-2"
            ],
            "orderCreatedTime": "Tue May 23 13:38:46 CEST 2023"
        }
    }
}

The following Rule pattern would match the above event, i.e., any event where:

• source is exactly kafka-connect.my-json-values-connector and
• detail.key starts with order and
• the field orderItems exists in the details.value object

{
  "source": ["kafka-connect.my-json-values-connector"],
  "detail": {
    "key": [{"prefix": "order"}],
    "value": {
      "orderItems": [{"exists": true}]
    }
  }
}

Common issues are around schema handling, authentication and authorization (IAM), and debugging the event flow.

If you see the following errors, check your connector configuration if it uses the correct key and value schema settings.

Error:

The following error is caused when the JsonConverter is used and configured to use a schema within the Kafka record. If the Kafka record was not produced with a JSON schema, i.e., only the JSON value, deserialization will fail with:

org.apache.kafka.connect.errors.DataException: JsonConverter with schemas.enable requires "schema" and "payload" 
fields and may not contain additional fields. If you are trying to deserialize plain JSON data, 
set schemas.enable=false in your converter configuration.

Resolution:

"value.converter": "org.apache.kafka.connect.json.JsonConverter",
"value.converter.schemas.enable": "false",

Error:

The following error is caused when an AvroConverter is used but the respective key/value is not Avro-encoded:

org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
org.apache.kafka.common.errors.SerializationException: Unknown magic byte!

Resolution:

Change the key and/or value converters from Avro to the actual schema/payload type stored in the topic.

When invalid IAM credentials are used, such as due to expired tokens or insufficient permissions, the connector will throw an exception after an PutEvents API call attempt to EventBridge or during key/value deserialization when an external schema registry with authentication is used. An example error message due to insufficient PutEvents permissions looks like:

org.apache.kafka.connect.errors.ConnectException: software.amazon.event.kafkaconnector.exceptions.EventBridgeWriterException: 
java.util.concurrent.ExecutionException: software.amazon.awssdk.services.eventbridge.model.EventBridgeException: 
User: arn:aws:sts::1234567890:assumed-role/some/role is not authorized to perform: events:PutEvents on resource: arn:aws:events:us-east-1:1234567890:event-bus/kafkabus because no identity-based policy allows the events:PutEvents action 
(Service: EventBridge, Status Code: 400, Request ID: e5ed0fb7-535d-4417-b38b-110f8495d0cb)

By default, the underlying AWS SDK client used will automatically handle throttle errors (exceptions) when the PutEvents ingestion quota for the account/region is exceeded. However, depending on your quota and ingestion rate, if the client keeps hitting the rate limit it might throw an exception to the connector. When setting aws.eventbridge.retries.max greater than 0, the connector will attempt to retry such a failed PutEvents attempt up to aws.eventbridge.retries.max. If aws.eventbridge.retries.max is 0 or the retry budget is exhausted, a terminal ConnectException is thrown and the task will be stopped.

We recommend to verify your PutEvents account quota for the specific AWS region and adjusting the Kafka Connect sink setting consumer.override.max.poll.records accordingly. For example, if your PutEvents quota is 500, setting consumer.override.max.poll.records=400 leaves enough headroom.

EventBridge has a limit of 256KB on the request size used in PutEvents. When a Kafka record exceeds this threshold, the connector will log a warning and ignore (skip) over the record. Optionally, a dead-letter topic can be configured where such records are sent to.

[2023-05-26 09:01:21,149] WARN [EventBridgeSink-Json|task-0] [@69c7029] Marking record as failed: code=413 message=EventBridge batch size limit exceeded topic=json-test partition=0 offset=0 (software.amazon.event.kafkaconnector.EventBridgeWriter:244)
[2023-05-26 09:01:21,149] WARN [EventBridgeSink-Json|task-0] [@69c7029] Dead-letter queue not configured: skipping failed record (software.amazon.event.kafkaconnector.EventBridgeSinkTask:147)
software.amazon.event.kafkaconnector.exceptions.EventBridgePartialFailureResponse: statusCode=413 errorMessage=EventBridge batch size limit exceeded topic=json-test partition=0 offset=0

The connector will periodically (asynchronously) on a per-task basis report the count of successful PutEvents API calls e.g.:

[2023-05-25 11:53:04,598] INFO [EventBridgeSink-Json|task-0] Total records sent=15 (software.amazon.event.kafkaconnector.util.StatusReporter:36)

By enabling TRACE-level logging, the connector will emit additional log messages, such as the underlying AWS SDK client configuration, records received from Kafka Connect, PutEvents stats, such as start, end time and duration, etc.

[2023-05-25 12:01:56,882] TRACE [EventBridgeSink-Json|task-0] [@69c7029] EventBridgeSinkTask put called with 1 records: [SinkRecord{kafkaOffset=0, timestampType=CreateTime} ConnectRecord{topic='json-test', kafkaPartition=0, key=my-key, keySchema=Schema{STRING}, value={sentTime=Thu May 25 14:01:56 CEST 2023}, valueSchema=null, timestamp=1685016116860, headers=ConnectHeaders(headers=)}] (software.amazon.event.kafkaconnector.EventBridgeSinkTask:57)
[2023-05-25 12:01:56,889] TRACE [EventBridgeSink-Json|task-0] [@69c7029] EventBridgeSinkTask putItems call started: start=2023-05-25T12:01:56.889640Z attempts=1 maxRetries=0 (software.amazon.event.kafkaconnector.EventBridgeSinkTask:77)
[2023-05-25 12:01:56,909] TRACE [EventBridgeSink-Json|task-0] [@69c7029] EventBridgeWriter sending request to eventbridge: PutEventsRequest(Entries=[PutEventsRequestEntry(Source=kafka-connect.json-test-connector, Resources=[], DetailType=kafka-connect-json-test, Detail={"topic":"json-test","partition":0,"offset":0,"timestamp":1685016116860,"timestampType":"CreateTime","headers":[],"key":"my-key","value":{"sentTime":"Thu May 25 14:01:56 CEST 2023"}}, EventBusName=arn:aws:events:us-east-1:1234567890:event-bus/kafkabus)]) (software.amazon.event.kafkaconnector.EventBridgeWriter:140)
[2023-05-25 12:01:57,242] TRACE [EventBridgeSink-Json|task-0] [@69c7029] EventBridgeWriter putEvents response: [PutEventsResultEntry(EventId=875b7f21-f098-8b55-ea7a-a4d235079bfb)] (software.amazon.event.kafkaconnector.EventBridgeWriter:142)
[2023-05-25 12:01:57,242] TRACE [EventBridgeSink-Json|task-0] [@69c7029] EventBridgeSinkTask putItems call completed: start=2023-05-25T12:01:56.889640Z completion=2023-05-25T12:01:57.242428Z durationMillis=352 attempts=1 maxRetries=0 (software.amazon.event.kafkaconnector.EventBridgeSinkTask:99)

Depending on your Kafka Connect environment, you can enable TRACE-level logging via environment variables on Kafka Connect using CONNECT_LOG4J_LOGGERS: "software.amazon.event.kafkaconnector=TRACE". Please consult your Kafka Connect documentation how to configure and change log levels for a particular connector.

Warning
Enabling TRACE-level logging can expose sensitive information due to logging record keys and values. It is strongly recommended to audit changes to the log level to guard against leaking sensitive data, such as personally identifiable information (PII).

See CONTRIBUTING for more information.

This project is licensed under the Apache-2.0 License.

A HUGE THANK YOU to @flo-mair and @maschnetwork for their initial contributions to this project.