How to fix `kafka: client has run out of available brokers to talk to (Is your cluster reachable?)` error - go

Question

I am developing an application which reads a message off of an sqs queue, does some stuff with that data, and takes the result and publishes to a kafka topic. In order to test locally, I'd like to set up a kafka image in my docker build. I am currently able to spin up aws-cli, localstack, and my app's containers locally using docker-compose. Separately, I am able to spin up kafka and zookeper without a problem as well. I am unable to get my application to communicate with kafka.
I've tried using two separate compose files, and also fiddled with the networks. Finally, I've referenced: https://rmoff.net/2018/08/02/kafka-listeners-explained/.
Here is my docker-compose file:
version: '3.7'
services:
localstack:
image: localstack/localstack:latest
container_name: localstack
env_file: .env
ports:
# Localstack endpoints for various API. Format is localhost:container
- '4563-4584:4563-4584'
- '8080:8080'
environment:
- SERVICES=sns:4575,sqs:4576
- DATA_DIR=/tmp/localstack/data
volumes:
# store data locally in 'localstack' folder
- './localstack:/tmp/localstack'
networks:
- my_network
aws:
image: mesosphere/aws-cli
container_name: aws-cli
# copy local JSON_DATA folder contents into aws-cli container's app folder
#volumes:
# - ./JSON_DATA:/app
env_file: .env
# bash entrypoint needed for multiple commands
entrypoint: /bin/sh -c
command: >
" sleep 10;
aws --endpoint-url=http://localstack:4576 sqs create-queue --queue-name input_queue;
aws --endpoint-url=http://localstack:4575 sns create-topic --name input_topic;
aws --endpoint-url=http://localstack:4575 sns subscribe --topic-arn arn:aws:sns:us-east-2:123456789012:example_topic --protocol sqs --notification-endpoint http://localhost:4576/queue/input_queue; "
networks:
- my_network
depends_on:
- localstack
my_app:
build: .
image: my_app
container_name: my_app
env_file: .env
ports:
- '9000:9000'
networks:
- my_network
depends_on:
- localstack
- aws
zookeeper:
image: confluentinc/cp-zookeeper:5.0.0
container_name: zookeeper
ports:
- 2181:2181
environment:
ZOOKEEPER_CLIENT_PORT: 2181
networks:
- my_network
kafka:
image: confluentinc/cp-kafka:5.0.0
ports:
- 9092:9092
depends_on:
- zookeeper
environment:
# For more details see See https://rmoff.net/2018/08/02/kafka-listeners-explained/
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
KAFKA_ADVERTISED_LISTENERS: INSIDE://localhost:9092
KAFKA_LISTENERS: INSIDE://localhost:9092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INSIDE:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: INSIDE
KAFKA_CREATE_TOPICS: "output_topic:2:2"
networks:
- my_network
networks:
my_network:
I would hope to see no errors as a result of publishing to this topic. Instead, I'm getting:
kafka: client has run out of available brokers to talk to (Is your cluster reachable?)
Any ideas what I may be doing wrong? Thank you for your help.

Answer 1

You've made the broker only resolvable within the Kafka container itself (or from your host to the container) by setting the listeners only to localhost.
If you want another Docker service to be able to reach that container, you'll have to add <some protocol>://kafka:<some port> to the advertised listeners, and make the listeners as not localhost
Where the protocol is also added to KAFKA_LISTENER_SECURITY_PROTOCOL_MAP
FWIW, That blog should cover all those bases.