mockcluster.go

/**
 * Copyright 2022 Confluent Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package main

import (
	"fmt"
	"os"

	"github.com/confluentinc/confluent-kafka-go/v2/kafka"
)

func main() {

	mockCluster, err := kafka.NewMockCluster(1)
	if err != nil {
		fmt.Printf("Failed to create MockCluster: %s\n", err)
		os.Exit(1)
	}
	defer mockCluster.Close()

	broker := mockCluster.BootstrapServers()

	p, err := kafka.NewProducer(&kafka.ConfigMap{"bootstrap.servers": broker})

	if err != nil {
		fmt.Printf("Failed to create producer: %s\n", err)
		os.Exit(1)
	}

	fmt.Printf("Created Producer %v\n", p)
	deliveryChan := make(chan kafka.Event)
	defer close(deliveryChan)

	topic := "Test"
	value := "Hello Go!"
	err = p.Produce(&kafka.Message{
		TopicPartition: kafka.TopicPartition{Topic: &topic, Partition: kafka.PartitionAny},
		Value:          []byte(value),
		Headers:        []kafka.Header{{Key: "myTestHeader", Value: []byte("header values are binary")}},
	}, deliveryChan)
	if err != nil {
		fmt.Printf("Produce failed: %s\n", err)
		os.Exit(1)
	}

	e := <-deliveryChan
	m := e.(*kafka.Message)

	if m.TopicPartition.Error != nil {
		fmt.Printf("Delivery failed: %v\n", m.TopicPartition.Error)
	} else {
		fmt.Printf("Delivered message to topic %s [%d] at offset %v\n",
			*m.TopicPartition.Topic, m.TopicPartition.Partition, m.TopicPartition.Offset)
	}

	c, err := kafka.NewConsumer(&kafka.ConfigMap{
		"bootstrap.servers":     broker,
		"broker.address.family": "v4",
		"group.id":              "group",
		"session.timeout.ms":    6000,
		"auto.offset.reset":     "earliest"})

	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to create consumer: %s\n", err)
		os.Exit(1)
	}
	defer c.Close()

	fmt.Printf("Created Consumer %v\n", c)

	err = c.SubscribeTopics([]string{topic}, nil)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to subscribe to topics: %s\n", err)
		os.Exit(1)
	}

	msg, err := c.ReadMessage(-1)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to read message: %s\n", err)
		os.Exit(1)
	}

	fmt.Println("received message: ", string(msg.Value))

}