“Streamline Your Data Flow: Integrating Apache Kafka with RESTful APIs”

Apache Kafka can be integrated with REST (Representational State Transfer) APIs to enable communication between Kafka and other systems that use REST. Different ways to achieve this, but one popular approach is to use a Kafka Connector that implements the Kafka Connect API.

Kafka Connect is a framework for connecting Kafka with external systems such as databases, key-value stores, and search indexes. It makes it easy to integrate Kafka with other systems in your stack.

One of the connectors that is available for this purpose is “Kafka Connect REST”. It is a Kafka-Connector that allows you to expose your Kafka topics as RESTful endpoints. It can be used to read and write messages to a topic, and it supports several different serialization formats, such as JSON, Avro, and Protobuf.

To use Kafka Connect REST, you’ll need to install and configure the connector and then create a RESTful endpoint that maps to a Kafka topic. Once the endpoint is created, you can use standard HTTP methods such as GET, POST, PUT, and DELETE to read and write messages to the topic.

json - Kafka - how to transform Rest service message to ingest into a kafka topic? - Stack Overflow

Here’s a detailed example of using Kafka Connect REST to expose a Kafka topic as a RESTful endpoint using the Kafka Connect REST connector.

Install and configure the Kafka Connect REST connector:

Download the latest version of the Kafka Connect REST connector from the Confluent Hub website.
Extract the downloaded file to a directory of your choice
Add the directory to the Kafka Connect plugin path by editing the connect-distributed.properties file and adding the following line:

plugin.path=/path/to/kafka-connect-rest

Start the Kafka Connect cluster, which includes a REST API for managing connectors

bin/connect-distributed.sh config/connect-distributed.properties

Create a RESTful endpoint that maps to a Kafka topic:

To create a RESTful endpoint for a topic named “my-topic”, you need to create a connector configuration file that defines the topic, the endpoint, and the serialization format.
For example, the following configuration file creates an endpoint at “http://localhost:8083/my-topic” that maps to the topic “my-topic” and uses JSON serialization:

{
    "name": "rest-source-my-topic",
    "config": {
        "connector.class": "io.confluent.connect.rest.RestSourceConnector",
        "key.converter": "org.apache.kafka.connect.json.JsonConverter",
        "value.converter": "org.apache.kafka.connect.json.JsonConverter",
        "rest.port": "8083",
        "rest.host.name": "localhost",
        "topic": "my-topic",
        "tasks.max": "1"
    }
}

Once the configuration file is created, you can post it to the Kafka Connect REST API to create the connector and the endpoint

curl -X POST -H "Content-Type: application/json" --data @config.json http://localhost:8083/connectors

Use standard HTTP methods such as GET, POST, PUT, and DELETE to read and write messages to the topic via the RESTful endpoint

To write a message to the topic via the RESTful endpoint, you can use a POST request and include the message in the request body. For example, the following command writes a message to the topic via the endpoint:

curl -X POST -H "Content-Type: application/json" --data '{"key": "1", "value": "Hello, World!"}' http://localhost:8083/my-topic

To read messages from the topic via the RESTful endpoint, you can use a GET request. For example, the following command retrieves all messages from the topic via the endpoint:

curl http://localhost:8083/my-topic

Note that this is just an example, and there are many other ways to configure and use the Kafka Connect REST connector to expose a Kafka topic as a RESTful endpoint. It depends on the specific requirements of your application.