SpringBoot application: Redis connection refused when running in Docker, works locally

Question

Why does Spring Boot try to connect to localhost:6379 when running inside Docker, even though I set SPRING_DATA_REDIS_HOST=app-redis in the environment variables? How can I make it connect to the Redis container correctly?

docker-compose.yml

services:
  # Database (MySQL)
  app-db:
    image: mysql:8.0
    container_name: myapp-db
    environment:
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
      MYSQL_DATABASE: myappdb
      MYSQL_USER: myappuser
      MYSQL_PASSWORD: ${DB_PASSWORD}
    volumes:
      - db_data:/var/lib/mysql
    restart: unless-stopped
    networks:
      - myapp-network
    healthcheck:
      test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-p${DB_ROOT_PASSWORD}"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 30s

  # Redis
  app-redis:
    image: redis:7-alpine
    container_name: myapp-redis
    ports:
      - "6379:6379"
    volumes:
      - redis_data:/data
    restart: unless-stopped
    networks:
      - myapp-network
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 5

  # Spring Boot backend
  app-backend:
    build:
      context: C:/aspring_workspace/cbt-enterprise
      dockerfile: Dockerfile
    container_name: myapp-backend
    environment:
      # License & Application Config
      - LICENSE_KEY=${LICENSE_KEY}
      - SPRING_APPLICATION_NAME=${SPRING_APPLICATION_NAME}
      - SPRING_PROFILES_ACTIVE=docker

      # Database Config
      - SPRING_DATASOURCE_URL=jdbc:mysql://app-db:3306/${MYSQL_DATABASE}
      - SPRING_DATASOURCE_USERNAME=${MYSQL_USER}
      - SPRING_DATASOURCE_PASSWORD=${DB_PASSWORD}

      # Redis Config
      - SPRING_DATA_REDIS_HOST=app-redis
      - SPRING_DATA_REDIS_PORT=6379
      - SPRING_DATA_REDIS_TIMEOUT=10000

      # JWT Config
      - JWT_SECRET=${JWT_SECRET}
      - JWT_EXPIRATIONMS=${JWT_EXPIRATIONMS}

      # Email Config
      - SPRING_MAIL_USERNAME=${EMAIL_USERNAME}
      - SPRING_MAIL_PASSWORD=${EMAIL_APP_PASSWORD}
      - APP_MAIL_FROM=${EMAIL_USERNAME}

      # Storage Config
      - PROCTOR_STORAGE_TYPE=${STORAGE_TYPE}
      - CBT_TEMPLATES_DIR=/templates

      # AWS S3 Config
      - AWS_S3_ACCESS_KEY=${AWS_ACCESS_KEY}
      - AWS_S3_SECRET_KEY=${AWS_SECRET_KEY}

    volumes:
      - ./templates:/templates
    depends_on:
      app-db:
        condition: service_healthy
      app-redis:
        condition: service_healthy
    ports:
      - "8080:8080"
    restart: unless-stopped
    networks:
      - myapp-network

  # Angular frontend
  app-frontend:
    build:
      context: C:/angular_workspace
      dockerfile: Dockerfile
    container_name: myapp-frontend
    depends_on:
      - app-backend
    ports:
      - "4200:80"
    restart: unless-stopped
    networks:
      - myapp-network

volumes:
  db_data:
  redis_data:

networks:
  myapp-network:
    driver: bridge

Exception (relevant part)

org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.translateException(LettuceConnectionFactory.java:1858) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1789) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1586) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.lambda$getConnection$0(LettuceConnectionFactory.java:1566) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.doInLock(LettuceConnectionFactory.java:1527) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1563) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedConnection(LettuceConnectionFactory.java:1249) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getConnection(LettuceConnectionFactory.java:1055) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisConnectionUtils.fetchConnection(RedisConnectionUtils.java:195) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:144) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:105) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:400) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:380) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisTemplate.doWithKeys(RedisTemplate.java:802) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.core.RedisTemplate.keys(RedisTemplate.java:645) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at com.almubaraksuleiman.cbts.examiner.service.ExamTimerServiceImpl.updateTimers(ExamTimerServiceImpl.java:80) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
    at org.springframework.scheduling.support.ScheduledMethodRunnable.runInternal(ScheduledMethodRunnable.java:130) ~[spring-context-6.2.8.jar:6.2.8]
    at org.springframework.scheduling.support.ScheduledMethodRunnable.lambda$run$2(ScheduledMethodRunnable.java:124) ~[spring-context-6.2.8.jar:6.2.8]
    at io.micrometer.observation.Observation.observe(Observation.java:498) ~[micrometer-observation-1.15.1.jar:1.15.1]
    at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:124) ~[spring-context-6.2.8.jar:6.2.8]
    at org.springframework.scheduling.config.Task$OutcomeTrackingRunnable.run(Task.java:85) ~[spring-context-6.2.8.jar:6.2.8]
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-6.2.8.jar:6.2.8]
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[na:na]
    at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) ~[na:na]
    at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]
    at java.base/java.lang.Thread.run(Thread.java:842) ~[na:na]
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to localhost/<unresolved>:6379
    at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:63) ~[lettuce-core-6.6.0.RELEASE.jar:6.6.0.RELEASE/643bd47]
    at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:41) ~[lettuce-core-6.6.0.RELEASE.jar:6.6.0.RELEASE/643bd47]
    at io.lettuce.core.AbstractRedisClient.getConnection(AbstractRedisClient.java:354) ~[lettuce-core-6.6.0.RELEASE.jar:6.6.0.RELEASE/643bd47]
    at io.lettuce.core.RedisClient.connect(RedisClient.java:220) ~[lettuce-core-6.6.0.RELEASE.jar:6.6.0.RELEASE/643bd47]
    at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.lambda$getConnection$1(StandaloneConnectionProvider.java:112) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at java.base/java.util.Optional.orElseGet(Optional.java:364) ~[na:na]
    at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.getConnection(StandaloneConnectionProvider.java:112) ~[spring-data-redis-3.5.1.jar:3.5.1]
    at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1787) ~[spring-data-redis-3.5.1.jar:3.5.1]
    ... 30 common frames omitted
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: localhost/127.0.0.1:6379
Caused by: java.net.ConnectException: Connection refused: no further information
    at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]
    at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]
    at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:946) ~[na:na]
    at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:336) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:339) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:784) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:732) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:658) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998) ~[netty-common-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.122.Final.jar:4.1.122.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.122.Final.jar:4.1.122.Final]
    at java.base/java.lang.Thread.run(Thread.java:842) ~[na:na]

ExamTimerServiceImpl.java

package com.almubaraksuleiman.cbts.examiner.service;

import com.almubaraksuleiman.cbts.dto.ExamSessionService;
import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.messaging.simp.SimpMessagingTemplate;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import java.util.Set;

@Service
@RequiredArgsConstructor
public class ExamTimerServiceImpl {

    private final StringRedisTemplate redisTemplate;
    private final SimpMessagingTemplate messagingTemplate;
    private ExamSessionService examSessionService;
    private final TestAutoSubmitService autoSubmitService;

    public void startTimer(Long sessionId, int durationInSeconds) {
        String key = "exam:" + sessionId + ":timeLeft";
        redisTemplate.opsForValue().set(key, String.valueOf(durationInSeconds));
        messagingTemplate.convertAndSend("/topic/timer/" + sessionId, durationInSeconds);
    }

    public int getTimeLeft(Long sessionId) {
        String key = "exam:" + sessionId + ":timeLeft";
        String value = redisTemplate.opsForValue().get(key);
        return value != null ? Integer.parseInt(value) : 0;
    }

    @Scheduled(fixedRate = 1000)
    public void updateTimers() {
        Set<String> keys = redisTemplate.keys("exam:*:timeLeft");
        if (keys == null) return;

        for (String key : keys) {
            int time = Integer.parseInt(redisTemplate.opsForValue().get(key));
            Long sessionId = Long.parseLong(key.split(":")[1]);

            if (time > 0) {
                redisTemplate.opsForValue().set(key, String.valueOf(time - 1));
                messagingTemplate.convertAndSend("/topic/timer/" + sessionId, time - 1);
            } else {
                autoSubmitService.completeExam(sessionId);
                redisTemplate.delete(key);
                messagingTemplate.convertAndSend("/topic/timer/" + sessionId, "0");
                messagingTemplate.convertAndSend("/topic/exam-completed/" + sessionId, "completed");
            }
        }
    }
}

Dockerfile

FROM eclipse-temurin:17-jre-alpine
WORKDIR /app

# Copy only the built jar
COPY target/*.jar app.jar

RUN addgroup -S spring && adduser -S spring -G spring
USER spring

EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]

application-docker.properties

# ===============================
# Redis (from docker-compose .env)
spring.data.redis.host=${SPRING_DATA_REDIS_HOST}
spring.data.redis.port=${SPRING_DATA_REDIS_PORT}
spring.data.redis.timeout=10000ms
#spring.redis.password=${SPRING_REDIS_PASSWORD}

how many profiles you have in your application because you show the application-docker.properties and there is nowhere in your execution of the application you are setting the docker profile. — Jorge Campos
– Jorge Campos, Commented Oct 2 at 20:21
Yes, I do have multiple profiles, application-docker.properties and application-local.properties, when running local , springboot application output logs showing local is picked as the profile,same as when running in docker springboot application output logs showing docker is picked as profile, from my docker-compose.yml you will see - SPRING_PROFILES_ACTIVE=docker. Every other services communicate with each other without any issue except for redis. — almubarak96
– almubarak96, Commented Oct 3 at 0:16

Noah · Accepted Answer · 2025-10-03 00:08:36Z

1

change redis host app-redis -> myapp-redis don't use servicename use container_name

answered Oct 3 at 0:08

Noah

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Community Oct 3 at 0:45

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SpringBoot application: Redis connection refused when running in Docker, works locally

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