Hello Ricardo,
Thanks much for your help. In deed it have fixed the problem.
On Thu, Jun 4, 2020 at 8:31 PM Ricardo Ferreira <rifer...@riferrei.com>
wrote:
> Anto,
>
> I am not 100% familiar with this image `confluentinc/cp-kafka` but there
> is a few things that you should try:
>
> 1) Make sure your `kafka` containers has this name set appropriately
>
> ```
>
> kafka:
> image: confluentinc/cp-enterprise-kafka:5.5.0
> container_name: *kafka*
> depends_on:
> - zookeeper
>
> ```
>
> 2) Set the list of protocols that Kafka will communicate externally
>
> ```
>
> KAFKA_LISTENER_SECURITY_PROTOCOL_MAP:
> PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
>
> ```
>
> 3) In your app container; provide the bootstrap server value with double
> quotes
>
> ```
>
> depends_on:
> - kafka
> - zookeeper
> - postgres
> - connector
> environment:
> BOOTSTRAP_SERVERS: *"kafka:9092"*
>
> ```
>
> Thanks,
>
> -- riferrei
> On 6/3/20 9:55 PM, Anto Aravinth wrote:
>
> I have a spring application, which should connect to the kafka. This is
> what my Docker file looks for spring application:
>
> ```
> FROM maven:3-jdk-11 as builder
> # create app folder for sources
> RUN mkdir -p /build
> WORKDIR /build
> COPY pom.xml /build
> #Download all required dependencies into one layer
> RUN mvn -B dependency:resolve dependency:resolve-plugins
> #Copy source code
> COPY src /build/src
> # Build application
> RUN mvn package
>
> FROM openjdk:8-jdk-alpine
> RUN addgroup -S spring && adduser -S spring -G spring
> USER spring:spring
> ARG JAR_FILE=target/*.jar
> COPY ${JAR_FILE} app.jar
> ENTRYPOINT ["java","-jar","/app.jar"]
> ```
>
> The kafka/Postgres/zookeeper everything other, comes from Docker images. So
> thought will run the application in docker compose, so that it looks like
> the following:
>
> version: '3.1'
> services:
> postgres:
> image: debezium/postgres
> environment:
> POSTGRES_PASSWORD: qwerty
> POSTGRES_USER: appuser
> volumes:
> - ./postgres:/data/postgres
> ports:
> - 6532:6532
> zookeeper:
> image: confluentinc/cp-zookeeper
> ports:
> - "2181:2181"
> environment:
> ZOOKEEPER_CLIENT_PORT: 2181
> kafka:
> image: confluentinc/cp-kafka
> depends_on:
> - zookeeper
> - postgres
> ports:
> - "9092:9092"
> environment:
> KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
> KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092
> KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
> KAFKA_LOG_CLEANER_DELETE_RETENTION_MS: 5000
> KAFKA_BROKER_ID: 1
> KAFKA_MIN_INSYNC_REPLICAS: 1
> KAFKA_ADVERTISED_HOST_NAME: kafka
> connector:
> image: debezium/connect:latest
> ports:
> - "8083:8083"
> environment:
> GROUP_ID: 1
> CONFIG_STORAGE_TOPIC: my_connect_configs
> OFFSET_STORAGE_TOPIC: my_connect_offsets
> BOOTSTRAP_SERVERS: kafka:9092
> depends_on:
> - zookeeper
> - postgres
> - kafka
> app-server:
> # Configuration for building the docker image for the backend
> service
> build:
> context: . # Use an image built from the specified dockerfile
> in the `polling-app-server` directory.
> dockerfile: Dockerfile
> ports:
> - "8080:8080" # Forward the exposed port 8080 on the
> container to port 8080 on the host machine
> restart: always
> depends_on:
> - kafka
> - zookeeper
> - postgres
> - connector
> environment:
> BOOTSTRAP_SERVERS: kafka:9092
>
> I pass an environment variable `BOOTSTRAP_SERVERS` with value as
> `kafka:9092` (since `localhost:9092` doesn't work inside my docker
> environment).
>
> And in my spring code, I get the value like the following:
>
> ```
> System.getenv("bootstrap.servers")
> // or
> System.getenv("BOOTSTRAP_SERVERS")
> ```
>
> however, when I run `docker-compose up`, I get the value as `null` for the
> above Java code. Not sure, what is the best way to get the docker resolved
> network for my kafka.
>
> So how to fix it so that java code picks up the Kafka broker inside the
> docker environment?
>
>
>
