Postgres container connection refused

Question

Docker-compose with 2 containers. 1st is a Postgres database and 2nd is a Java Spring Boot application. For running, I use further docker-compose config file: docker-compose.yml

version: "3.7"

services:
  db-service:
    image: postgres
    restart: always
    volumes:
      - /home/ec2-user/dbdata:/var/lib/postgresql/data
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: 1
      POSTGRES_DB: auth
    ports:
      - 5432:5432

  auth-service:
    build: .
    restart: always
    depends_on:
      - db-service
    links:
      - db-service
    ports:
      - 80:80

I suppose to use /home/ec2-user/dbdata to containing database data and after all, data is created. successfully. And log of postgres container is:

PostgreSQL init process complete; ready for start 2021-01-07 01:36:16.786 UTC [1] LOG: starting PostgreSQL 13.1 (Debian 13.1-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit 2021-01-07 01:36:16.786 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432 2021-01-07 01:36:16.786 UTC [1] LOG: listening on IPv6 address "::", port 5432 2021-01-07 01:36:16.790 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432" 2021-01-07 01:36:16.795 UTC [76] LOG: database system was shut down at 2021-01-07 01:36:16 UTC 2021-01-07 01:36:16.800 UTC [1] LOG: database system is ready to accept connections

But Java app throws an error:

org.postgresql.util.PSQLException: Connection to 127.0.0.1:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

But in port mapping is 5432:5432.

And data source properties into Java app is:

spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://127.0.0.1:5432/auth
spring.datasource.username=postgres
spring.datasource.password=1

What is can be the reason for this error?

james.lorenzen james.lorenzen · Accepted Answer · 2021-01-07T02:08:14

It's not working because the java app is pointed to 127.0.0.1 which is local to the java container and postgres is not running in that container. In your properties file change this line:

spring.datasource.url=jdbc:postgresql://127.0.0.1:5432/auth

to

spring.datasource.url=jdbc:postgresql://db-service:5432/auth

Using db-service as the host comes from the name of the service in your docker-compose.yml file. See the docker compose networking page for more information.

Postgres container connection refused

2 Answers