RabbitMQ not working when services are dockerized-CodePudding

So I have 2 services. Kweet (which is a tweet) and User. When I run the 2 services manually rest of the services in docker, it works. Rest of services include MongoDB, RabbitMQ, Spring Cloud Gateway, Eureka Discovery. But the moment I run the 2 (micro)services in Docker (I just use a docker compose), the rabbitmq functionality stops working. The normal API calls work, it's specifically the RabbitMQ calls that fail.

RabbitMQ functionality:

EditUsername, edits username in user-service. 
Than sends data via RabbitMQ (this is where it goes wrong I think) to kweet-service where it edits the username of a kweet.

Docker-compose file:

version: '3.8'

services:
  eureka-service:
    build: ./eureka-discovery-service
    restart: always
    container_name: eureka-service
    ports:
      - 8087:8087

  api-gateway:
    build: ./api-gateway
    restart: always
    container_name: api-gateway
    depends_on:
      - eureka-service
    ports:
      - 8080:8080

  user:
    build: ./user
    restart: unless-stopped
    container_name: user-ms
    ports:
      - 8081:8081
    depends_on:
      - eureka-service

  kweet:
    build: ./kweet
    restart: unless-stopped
    container_name: kweet-ms
    depends_on:
      - eureka-service
    ports:
    - 8082:8082

  mongodb:
    image: mongo
    restart: always
    container_name: mongodb
    ports:
      - 27017:27017

  rabbitmq:
    image: rabbitmq:management
    restart: always
    container_name: rabbitmq
    ports:
      - 5672:5672
      - 15672:15672

When I try to make a call the console shows:

user-ms  |  2022-04-27 08:52:04.823  INFO 1 --- [nio-8081-exec-4] o.s.a.r.c.CachingConnectionFactory : Attempting to connect to: [localhost:5672]

The postman status I get back is 503 Service Unavailable which isn't from any try-catch's I made. Anybody have any clue where the problem might be?

EDIT [3]: Found this source (https://www.linkedin.com/pulse/binding-your-docker-app-container-rabbitmq-phani-bushan/) that got rid of my 503 Service Unavailable error. The problem I found now is that whenever I start up the containers, it generates new queues and exchanges that aren't the ones I set up in my application.properties.

CodePudding user response：

When you dockerize your services are no longer listening in localhost. If you need to network connect services you need to use container_name instead of localhost.

localhost points to the container itself, where only one service is listening. Do not mistake for when you develop on your laptop without containers, where everything is in localhost

More about this here

By default Compose sets up a single network for your app. Each container for a service joins the default network and is both reachable by other containers on that network, and discoverable by them at a hostname identical to the container name.

You must configure, somewhere in your user-ms application (we do not know what kind of applicatin is), that RabbitMQ service is listening at rabbitmq (container_name) not localhost.

CodePudding user response：

Try to use the container with environment variables. For me it is enough for working.

  rabbitmq:
    image: rabbitmq:management
    restart: always
    container_name: rabbitmq
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
      RABBITMQ_DEFAULT_VHOST: /
    ports:
      - 5672:5672
      - 15672:15672

I can open this container in a browser: http://localhost:15672/

I use PHP FPM and Symfony and I pass env value to this container to connect to rabbitmq.

services:
    php-fpm:
        environment:
            ENQUEUE_DSN: amqp://guest:guest@rabbitmq:5672

For Java you need to find and define or redefine application properties. The config may use the default value for localhost, like this spring.rabbitmq.host=localhost, but you need to use Docker's host, it is rabbitmq.

spring.rabbitmq.host=rabbitmq
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest