Redis refuses connection to Spring Boot via Docker Compose

I developed a spring boot application to store login information via redis. I have following docker-compose.yml:

version: "3.9"services:  web:    build: .    ports:      - "8082:8082"    links:      - redis  redis:    image: redis    container_name: redis    hostname: redis-db    ports:      - "6379:6379"    command: redis-server --port 6379 --bind 0.0.0.0 --protected-mode no

Dockerfile:

FROM openjdk:8-jre-alpineVOLUME /tmpCOPY app.jar app.jarEXPOSE 8082ENTRYPOINT ["java", "-jar",  "app.jar"]

In the Spring Boot Application, I just use following application.properties to setup the Redis Connection:

server.port = 8082spring.redis.host=redis-dbspring.redis.port=6379

I access the repository via CrudRepository and QueryByExampleExecutor. Every time I try to access the data, I get the following error:

sgartner-web-1  | 2021-11-25 01:22:53.600 ERROR 1 --- [nio-8082-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379] with root causesgartner-web-1  | sgartner-web-1  | java.net.ConnectException: Connection refusedsgartner-web-1  |       at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[na:1.8.0_212]sgartner-web-1  |       at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) ~[na:1.8.0_212]sgartner-web-1  |       at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:330) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:707) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493) ~[netty-transport-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986) ~[netty-common-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.69.Final.jar!/:4.1.69.Final]sgartner-web-1  |       at java.lang.Thread.run(Thread.java:748) [na:1.8.0_212]

I already have tested the application "normal" instances of redis and the application. What seems odd to me is the "Unable to connect to localhost:6379]", even though I'm not trying to connect to localhost.

Testing this behavior while running the application outside of a container shows, that it recognises the changed hostname and doesn't try to connect to localhost...

The specified redis command also doesn't seem to be the problem: tested this with running redis outside of a container with the same command and trying to connect to it via a VM.

I would really appreciate a solution or another possible cause to look into. Thanks to whoever replies to this!