细节：我们已经靠岸了 Kafka , Cassandra 以及 Spark ，使用 wurstmeister/kafka , strapdata/elassandra 以及 bde2020/spark-master docker中的图像。
我们要做的是使用连接器连接以下各项：
Kafka流到Spark流
Spark流到Cassandra
Kafka河到Cassandra
问题是我们不知道它是否工作正常，因为这些技术对我们来说听起来很新。
图形表示法：

重要文件：
docker-compose.yml公司

version: '2'
services:
  spark:
    container_name: spark
    image: bde2020/spark-master
    ports: 
      - 9180:8080
      - 9177:7077
      - 9181:8081
    links: 
      - elassandra
    volumes:
hosein:/var/lib/docker/volumes/data/python
      - /home/mostafa/Desktop/kafka-test/together/cassandra/mostafa-hosein:/var/lib/docker/volumes/data/python

  elassandra:
    image: strapdata/elassandra
    container_name: elassandra
    build: /home/mostafa/Desktop/kafka-test/together/cassandra
    env_file:
      - /home/mostafa/Desktop/kafka-test/together/cassandra/conf/cassandra.env
    volumes:
      - /home/mostafa/Desktop/kafka-test/together/cassandra/jarfile:/var/lib/docker/volumes/data/_data
    ports:
      - '7000:7000'
      - '7001:7001'
      - '7199:7199'
      - '9042:9042'
      - '9142:9142'
      - '9160:9160'
      - '9200:9200'
      - '9300:9300'

  zookeeper:
    image: wurstmeister/zookeeper
    container_name: zookeeper
    ports:
      - "2181:2181"

  kafka:
    build: .
    container_name: kafka
    links:
     - zookeeper
    ports:
      - "9092:9092"
    environment:
      KAFKA_ADVERTISED_HOST_NAME: localhost
      KAFKA_ADVERTISED_PORT: 9092
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_OPTS: -javaagent:/usr/app/jmx_prometheus_javaagent.jar=7071:/usr/app/prom-jmx-agent-config.yml
      CONNECTORS: elassandra
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    depends_on: 
      - elassandra

  kafka_connect-cassandra:
    image: datamountaineer/kafka-connect-cassandra
    container_name: kafka-connect-cassandra
    ports:
      - 8083:8083
      - 9102:9102
    environment: 
      - connect.cassandra.contact.points=localhost
      - KAFKA_ZOOKEEPER_CONNECT =  "zookeeper:2181"
      - KAFKA_ADVERTISED_LISTENERS= "kafka:9092"
      - connect.cassandra.port=9042
      - connector.class=com.datamountaineer.streamreactor.connect.cassandra.sink.CassandraSinkConnector
      - tasks.max=1
    depends_on:
      - kafka
      - elassandra

dockerfile文件

FROM wurstmeister/kafka
ADD prom-jmx-agent-config.yml /usr/app/prom-jmx-agent-config.yml
ADD jmx_prometheus_javaagent-0.10.jar /usr/app/jmx_prometheus_javaagent.jar
COPY wait-for-it.sh /wait-for-it.sh
RUN chmod +x /wait-for-it.sh
CMD ["/wait-for-it.sh", "zookeeper:2181", "--", "start-kafka.sh"]

例如：我加了一个例子 CONNECTOR: elassandra 但是我没有遇到任何错误，也不确定它是否是一个有效的环境变量！
如何验证环境变量并测试连接器是否正常工作？