How to forward ports in docker-compose?

Question

Docker

I'm new to devOps, if I ask a question incorrectly, please don't swear too much.

The doker-compose file has several microservices, postgres and kafka. Problem : Microservices do not see each other and kafka. Only the server service on port 8080 and postgres on port 5432 stick out. How to forward ports and what URL should be specified in @FeignClient in the client class?

docker-compose:

version: '3.8'

volumes:
  pg_market:

services:
  server:
    image: 'server:latest'
    build:
      context: .
    container_name: server
    depends_on:
      - pg_db
    ports:
      - "8080:8080"
    links:
      - pg_db:database
  recommendation:
    image: 'recommendation:latest'
    build:
      context: .
    container_name: recommendation
    depends_on:
      - pg_db
    ports:
      - "8082:8082"
    links:
      - pg_db:database
  pg_db:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=1
      - POSTGRES_USER=postgres
      - POSTGRES_DB=postgres
    volumes:
      - pg_market:/var/lib/postgresql/data
    ports:
      - "5432:5432"
  kafka:
    image: wurstmeister/kafka
    ports:
      - "9092:9092"
    environment:
      KAFKA_ADVERTISED_HOST_NAME: localhost
      KAFKA_CREATE_TOPICS: recommendation
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181

And for example, application.yaml :

server:
  port: 8082
spring:
  datasource:
    url: jdbc:postgresql://database/postgres
    driver-class-name: org.postgresql.Driver
    username: postgres
    password: 1
kafka:
  bootstrap-servers: localhost:9092
  client-id: local
  auto-commit-interval: 1000
  topic: recomendation

@Component
@FeignClient(name = "market", url = "localhost:8082/api/v1/")
@EnableDiscoveryClient
public interface Client {

}

Answer 1

All I had to do was add "network_mode: host" to docker-compose. After the file took the following form, everything worked:

version: '3.8'

volumes:
  pg_market:

services:
  server:
    image: 'server:latest'
    build:
      context: .
    container_name: server
    depends_on:
      - pg_db
    ports:
      - "8080:8080"
    network_mode: host
    links:
      - pg_db:database
  recommendation:
    image: 'recommendation:latest'
    build:
      context: .
    container_name: recommendation
    depends_on:
      - pg_db
    ports:
      - "8082:8082"
    network_mode: host
    links:
      - pg_db:database
  pg_db:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=1
      - POSTGRES_USER=postgres
      - POSTGRES_DB=postgres
    volumes:
      - pg_market:/var/lib/postgresql/data
    ports:
      - "5432:5432"
    network_mode: host
  kafka:
    image: wurstmeister/kafka
    ports:
      - "9092:9092"
    network_mode: host
    environment:
      KAFKA_ADVERTISED_HOST_NAME: localhost
      KAFKA_CREATE_TOPICS: recommendation
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181

Answer 2

Since docker-compoe is used, services will automatically connect to the virtual network and will be able to access each other by the name of the service (if there is no need to access the service from the host machine or from outside it, then ports can not be forwarded).
For example, to connect to kafka in the config, you must specify:

kafka:
  bootstrap-servers: kafka:9092
  client-id: local
  auto-commit-interval: 1000
  topic: recomendation