No resolvable bootstrap urls given in bootstrap.servers on maven install - spring-boot

Question

I am building up a jar file for my spring boot microservice, but upon maven install i am getting the error as stated below.
Caused by: org.apache.kafka.common.config.ConfigException: No resolvable bootstrap urls given in bootstrap.servers
at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:89) ~[kafka-clients-3.1.1.jar:na]
at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:48) ~[kafka-clients-3.1.1.jar:na]
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:730) ~[kafka-clients-3.1.1.jar:na]
my docker-compose file for the application is
version: '2'
services:
zookeeper:
image: confluentinc/cp-zookeeper:latest
restart: always
environment:
ZOOKEEPER_CLIENT_PORT: 2181
ZOOKEEPER_TICK_TIME: 2000
ports:
- 2181:2181
networks:
- app-network
kafka:
image: confluentinc/cp-kafka:latest
container_name: kafka
restart: always
depends_on:
- zookeeper
ports:
- 9092:9092
environment:
KAFKA_BROKER_ID: 1
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
networks:
- app-network
mongodb:
image: mongo:latest
restart: always
container_name: mongodb
networks:
- app-network
ports:
- 27017:27017
matching-engine-helper:
image: matching-engine-helper:latest
restart: always
container_name: "matching-engine-helper"
networks:
- app-network
ports:
- 9192:9192
depends_on:
- mongodb
- zookeeper
- kafka
matching-engine-core:
image: matching-engine-core:latest
restart: always
container_name: "matching-engine-core"
networks:
- app-network
ports:
- 9191:9191
depends_on:
- matching-engine-helper
- zookeeper
- kafka
- mongodb
networks:
app-network:
driver: bridge
and the application.yml is
spring:
data:
mongodb:
database: matching-engine-mongodb
host: mongodb
port: 27017
kafka:
bootstrap-servers: kafka:9092
server:
port: 9192
let me know if i need some environment variable's configuration here. as its running fine on local environment on local host but not on docker containers as i am unable to make a jar out of it.

Answer 1

Assuming mvn install is running on your host, then your host doesn't know how to resolve kafka as a DNS name running in a container. It that's what you wanted, then you should rename your file to application-docker.yml and use Spring profiles to properly override any defaults when you actually do run your code in a container. In your case, you would need to have localhost:29092 for Kafka, and similarly use localhost:27017 for Mongo in your default application.yml. You can also use environment variables for those two properties rather than hard-code them.
Or, if mvn install is running in a Docker layer itself, then that is completely isolated from other Docker networks. You can pass --network flag to docker build, though.
Assuming you don't want to mvn install -DskipTests, ideally, your tests do not rely on external services to be running. If you want to run a Kafka unit test, which is failing to connect, then you should either mock that, or using Spring-Kafka's EmbeddedKafka for integration-tests.
Worth mentioning that Spring boot has a Maven plugin for building Docker images, and it doesn't need a JAR to do so.