spring boot app과 redis cluster를 docker로 사용할 때 Redis connection failed 발생

• 발생문제
  • redis cluster를 docker로 기동하고 있는데, spring boot app을 docker로 기동해야하는 필요가 생김.
  • redis cluster는 localhost로 연결하고 있었는데, spring boot app이 docker가 되면서 redis cluster의 컨테이너명("redis-cluster")으로 변경함.
  • 로그를 보면 redis에 연결에 성공하는 로그도 보이나, 연결 실패도 발생함.
    • 연결 성공 로그

{"level":"DEBUG","message":"Connecting to Redis at redis-cluster:6379: Success","stackTrace":""}

• • • 연결 실패 로그

{"level":"ERROR", "message":"Application run failed", "stackTrace":"org.springframework.context.ApplicationContextException: Failed to start bean 'springSessionRedisMessageListenerContainer'; nested exception is org.springframework.data.redis.listener.adapter.RedisListenerExecutionFailedException: org.springframework.data.redis.RedisConnectionFailureException: Redis connection failed; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Redis connection failed; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]\n \tat org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181)\n Caused by: org.springframework.data.redis.listener.adapter.RedisListenerExecutionFailedException: org.springframework.data.redis.RedisConnectionFailureException: Redis connection failed; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Redis connection failed; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]\n \tat org.springframework.data.redis.listener.RedisMessageListenerContainer.lazyListen(RedisMessageListenerContainer.java:275)\nCaused by: org.springframework.data.redis.RedisConnectionFailureException: Redis connection failed; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]\n \tat org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:66)\nCaused by: io.lettuce.core.RedisConnectionException: Unable to connect to [redis://*********@redis-cluster, redis://*********@redis-cluster:6380, redis://*********@redis-cluster:6381]\n \tat io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78)\nCaused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: /127.0.0.1:6381\n Caused by: java.net.ConnectException: finishConnect(..) failed: Connection refused\n \tat io.netty.channel.unix.Errors.newConnectException0(Errors.java:155)\n"}

• 해결방법
  • 기존에 localhost가 동작했으니 "host.internal.docker"를 이용 => 정확한 이유는 모르겠지만 실패.
  • spring boot app이 redis cluster의 네트워크를 이용하도록 설정
    • 기존 docker-compose:

services:
    spring-boot-app:
        ports:
            - 8888:8888
    redis-cluster:
        container_name: redis-cluster
        command: redis-server /conf/redis.conf
        image: redis:alpine
        ports:
            - 6379:6379
            - 6380:6380
             - 6381:6381

• • 변경 docker-compose:

services:
    spring-boot-app:
        network_mode: service:redis-cluster
     redis-cluster:
         container_name: redis-cluster
         command: redis-server /conf/redis.conf
         image: redis:alpine
         ports:
             - 6379:6379
             - 6380:6380
             - 6381:6381
             - 8888:8888

• 마무리
  • 좋은 해결방법인지는 모르겠지만 어차피 검증서버는 redis가 잘 움직이고 있으므로 더 찾아보지 않고 이걸로 종결.