如何访问没有ip地址的postgres-docker容器other docker容器

Question

How to access postgres-docker container other docker container without ip address? I want to store data in postgres by using myweb. in jar given host like localhost:5432/db..

Here my compose file:

version: "3"

services:
   myweb:
    build: ./myweb
    container_name: app
    ports:
      - "8080:8080"
      - "9090:9090"
    networks:
      - front-tier
      - back-tier
    depends_on:
      - "postgresdb"

   postgresdb:
    build: ./mydb
    image: ppk:postgres9.5
    volumes:
      - dbdata:/var/lib/postgresql
    ports:
      - "5432:5432"
    networks:
     - back-tier

volumes:
   dbdata: {}

networks:
  front-tier:
  back-tier:

Answer 1

Instead of localhost:5432/db.. use postgresdb:5432/db.. connection string.

By default the container has the same hostname as the service name.

---

Here is my minimal working example, which is connecting a java client (boxfuse/flyway) with postgres server. The most important part is the heath check , which is delaying the start of the myweb container to the time when postgres is ready to accept connections.

Note that this can be directly executed by docker-compose up , it dosen't have any other dependencies. Both the images are from docker hub.

version: '2.1'

services:
   myweb:
    image: boxfuse/flyway
    command: -url=jdbc:postgresql://postgresdb/postgres -user=postgres -password=123 info
    depends_on:
      postgresdb:
        condition: service_healthy

   postgresdb:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=123
    healthcheck:
      test: "pg_isready -q -U postgres"      

Answer 2

That is the Docker Networking problem. The solution is to use postgresdb:5432/db in place of localhost:5432/db because the two service is in the same.network named back-tier and docker deamon will use name service like a DNS name to make communication between the two container. I think that my solution will help you so.