How to connect from docker-compose to Host PostgreSQL?

Question

I have a server with installed PostgreSQL. All my services work in containers (docker-compose). I want to use my Host PostgreSQL from containers. Buy I have the error:

  Unable to obtain Jdbc connection from DataSource (jdbc:postgresql://localhost:5432/shop-bd) for user 'shop-bd-user': Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
  ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  SQL State  : 08001
  Error Code : 0
  Message    : Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

  Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
  Connection refused (Connection refused)

My docker-compose is using host network_mode, like this:

version: '3'
services:
  shop:  
    container_name: shop
    build: ./shop
    hostname: shop
    restart: always   
    ports:
      - 8084:8084
    network_mode: "host"

My database connection URL is: jdbc:postgresql://localhost:5432/shop-bd

Answer 1

Updated Apri, 2018

According to the document, from version 18.03 onwards, using host.docker.internal as DNS works for me, without specifying neither --net=host or network_mode: "host"

Answer 2

This would have worked if you were on linux OS. But this won't work on Mac or Windows. The thing is that when you use --net=host, you still are not on host network. That is the limitation of how docker for windows work

Instead of localhost you need to use docker.for.win.localhost as the host. This is a special DNS name which is available on Docker for Windows when you want to refer to the host localhost

Answer 3

Cautionary note: using the --net=host, or network_mode: "host" will prevent your container from registering with Eureka and will break any kind of API gateway you've got unless they all run on the same network.

Answer 4

1) ensure that your postgresql instance is listening to all addresses and not only localhost.

In postgresql.conf set listen_addresses as follows:

listen_addresses='*'

2) you are trying to connect from your container to localhost:5432 . That is NOT your host's IP address, but the address of your container's loopback device. You need to use your docker bridge IP address instead.