minimal docker compose using KRaft and simple golang sarama code to list topics

docker-compose.yml

# Minimal KRaft Kafka cluster with one broker
# create a topic with:
# docker exec -it kafka-compose-test-kafka-1 /opt/kafka/bin/kafka-topics.sh --create --topic new-topic --partitions 1 --replication-factor 1 --bootstrap-server localhost:9092

version: '3'
services:
  kafka:
    image: apache/kafka:3.8.0
    ports:
      - "9092:9092"
    environment:
      KAFKA_NODE_ID: 1
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: CONTROLLER:PLAINTEXT,BROKER:PLAINTEXT,EXTERNAL:PLAINTEXT
      KAFKA_LISTENERS: CONTROLLER://:19093,BROKER://:29092,EXTERNAL://0.0.0.0:9092
      KAFKA_ADVERTISED_LISTENERS: BROKER://kafka:29092,EXTERNAL://localhost:9092
      KAFKA_CONTROLLER_QUORUM_VOTERS: '1@kafka:19093'
      KAFKA_PROCESS_ROLES: 'broker,controller'
      KAFKA_INTER_BROKER_LISTENER_NAME: 'BROKER'
      KAFKA_CONTROLLER_LISTENER_NAMES: 'CONTROLLER'
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
      KAFKA_AUTO_CREATE_TOPICS_ENABLE: 'true'

main.go

// quick `klist` application to list topics on a kafka cluster using Sarama
package main

import (
	"fmt"
	"log"
	"os"
	"strings"

	"github.com/IBM/sarama"
)

func main() {
	if len(os.Args) != 2 {
		fmt.Println("Usage: kafka-topics-lister <broker:port>")
		os.Exit(1)
	}

	// Create config
	config := sarama.NewConfig()
	config.Version = sarama.V3_0_0_0 // Kafka 3.0+ version

	// Create client
	brokers := []string{os.Args[1]}
	client, err := sarama.NewClient(brokers, config)
	if err != nil {
		log.Fatalf("Error creating client: %v", err)
	}
	defer client.Close()

	// Get topics
	topics, err := client.Topics()
	if err != nil {
		log.Fatalf("Error getting topics: %v", err)
	}

	// Print topics
	if len(topics) == 0 {
		fmt.Println("No topics found")
		return
	}

	fmt.Println("Topics:")
	fmt.Println(strings.Join(topics, "\n"))
}

running the commands

# create the topic
docker exec -it kafka-compose-test-kafka-1 /opt/kafka/bin/kafka-topics.sh --create --topic new-topic --partitions 1 --replication-factor 1 --bootstrap-server localhost:9092


# running golang code above takes 20ms to list the topic
time ./klist 127.0.0.1:9092
Topics:
new-topic
./klist 127.0.0.1:9092  0.00s user 0.00s system 31% cpu 0.021 total

# kcat (brew install kcat) also takes 20ms
time kcat -L -b 127.0.0.1:9092
Metadata for all topics (from broker -1: 127.0.0.1:9092/bootstrap):
 1 brokers:
  broker 1 at localhost:9092 (controller)
 1 topics:
  topic "new-topic" with 1 partitions:
    partition 0, leader 1, replicas: 1, isrs: 1
kcat -L -b 127.0.0.1:9092  0.01s user 0.01s system 72% cpu 0.029 total