---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:6.2.0
    hostname: zookeeper
    ports:
      - '32181:32181'
    environment:
      ZOOKEEPER_CLIENT_PORT: 32181
      ZOOKEEPER_TICK_TIME: 2000
    extra_hosts:
      - "moby:127.0.0.1"

  kafka:
    image: confluentinc/cp-enterprise-kafka:6.2.0
    hostname: kafka
    ports:
      - '9092:9092'
      - '29092:29092'
    depends_on:
      - zookeeper
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:29092,PLAINTEXT_HOST://localhost:9092
      KAFKA_AUTO_CREATE_TOPICS_ENABLE: "false"
      KAFKA_METRIC_REPORTERS: io.confluent.metrics.reporter.ConfluentMetricsReporter
      CONFLUENT_METRICS_REPORTER_BOOTSTRAP_SERVERS: kafka:29092
      CONFLUENT_METRICS_REPORTER_ZOOKEEPER_CONNECT: zookeeper:32181
      CONFLUENT_METRICS_REPORTER_TOPIC_REPLICAS: 1
      CONFLUENT_METRICS_ENABLE: 'true'
      CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'
    extra_hosts:
      - "moby:127.0.0.1"

  schema-registry:
    image: confluentinc/cp-schema-registry:6.2.0
    hostname: schema-registry
    depends_on:
      - zookeeper
      - kafka
    ports:
      - '8081:8081'
    environment:
      SCHEMA_REGISTRY_HOST_NAME: schema-registry
      SCHEMA_REGISTRY_KAFKASTORE_CONNECTION_URL: zookeeper:32181
    extra_hosts:
      - "moby:127.0.0.1"

  # This "container" is a workaround to pre-create topics for the Kafka Music application
  # until we have a more elegant way to do that.
  kafka-create-topics:
    image: confluentinc/cp-kafka:6.2.0
    depends_on:
      - kafka
    hostname: kafka-create-topics
    # We defined a dependency on "kafka", but `depends_on` will NOT wait for the
    # dependencies to be "ready" before starting the "kafka-create-topics"
    # container;  it waits only until the dependencies have started.  Hence we
    # must control startup order more explicitly.
    # See https://docs.docker.com/compose/startup-order/
    command: "bash -c 'echo Waiting for Kafka to be ready... && \
                       cub kafka-ready -b kafka:29092 1 20 && \
                       kafka-topics --create --topic play-events --if-not-exists --zookeeper zookeeper:32181 --partitions 4 --replication-factor 1 && \
                       kafka-topics --create --topic song-feed --if-not-exists --zookeeper zookeeper:32181 --partitions 4 --replication-factor 1 && \
                       sleep infinity'"
    environment:
      # The following settings are listed here only to satisfy the image's requirements.
      # We override the image's `command` anyways, hence this container will not start a broker.
      KAFKA_BROKER_ID: ignored
      KAFKA_ZOOKEEPER_CONNECT: ignored
    extra_hosts:
      - "moby:127.0.0.1"

  # Continuously generates input data for the Kafka Music application.
  kafka-music-data-generator:
    image: confluentinc/kafka-streams-examples:6.2.0
    hostname: kafka-music-data-generator
    depends_on:
      - kafka
      - schema-registry
      - kafka-create-topics
    # Control startup order similarly to the "kafka-create-topics" container above.
    command: "bash -c 'echo Waiting for Kafka to be ready... && \
                       cub kafka-ready -b kafka:29092 1 20 && \
                       echo Waiting for Confluent Schema Registry to be ready... && \
                       cub sr-ready schema-registry 8081 20 && \
                       java -cp /usr/share/java/kafka-streams-examples/kafka-streams-examples-6.2.0-standalone.jar \
                       io.confluent.examples.streams.interactivequeries.kafkamusic.KafkaMusicExampleDriver \
                       kafka:29092 http://schema-registry:8081'"
    environment:
      STREAMS_BOOTSTRAP_SERVERS: ignored
      STREAMS_SCHEMA_REGISTRY_HOST: ignored
      STREAMS_SCHEMA_REGISTRY_PORT: ignored
      KAFKA_MUSIC_APP_REST_HOST: ignored
      KAFKA_MUSIC_APP_REST_PORT: ignored
    extra_hosts:
      - "moby:127.0.0.1"

  # Runs the Kafka Music application.
  kafka-music-application:
    image: confluentinc/kafka-streams-examples:6.2.0
    hostname: kafka-music-application
    depends_on:
      - kafka
      - schema-registry
      - kafka-create-topics
    # Control startup order similarly to the "kafka-create-topics" container above.
    # Note: The container's `run` script will perform the same readiness checks
    # for Kafka and Confluent Schema Registry, but that's ok because they complete fast.
    # The reason we check for readiness here is that we can insert a sleep time
    # for topic creation before we start the application.
    #
    # TODO: Once https://issues.apache.org/jira/browse/KAFKA-5037 is resolved,
    #       we can remove this `command` and use the image as-is.
    command: "bash -c 'echo Waiting for Kafka to be ready... && \
                       cub kafka-ready -b kafka:29092 1 20 && \
                       echo Waiting for Confluent Schema Registry to be ready... && \
                       cub sr-ready schema-registry 8081 20 && \
                       echo Waiting a few seconds for topic creation to finish... && \
                       sleep 2 && \
                       /etc/confluent/docker/run'"
    ports:
      - '7070:7070'
    environment:
      STREAMS_BOOTSTRAP_SERVERS: kafka:29092
      STREAMS_SCHEMA_REGISTRY_HOST: schema-registry
      STREAMS_SCHEMA_REGISTRY_PORT: 8081
      KAFKA_MUSIC_APP_REST_HOST: kafka-music-application
      KAFKA_MUSIC_APP_REST_PORT: 7070
    extra_hosts:
      - "moby:127.0.0.1"