Connect to postgresql container from another container (Docker)

Question

I have am trying to follow this tutorial and set up a postgresql container.

I have the following script:

#!/bin/bash
# wait-for-postgres.sh

set -e

host="$1"
shift
cmd="$@"

until psql -h "$host" -U "postgres" -c '\l'; do
  >&2 echo "Postgres is unavailable - sleeping"
  sleep 1
done

>&2 echo "Postgres is up - executing command"
exec $cmd

And the following docker-compose.yml:

version: '2'
services:
  server:
    build: .
    ports:
      - 3030:3030
    depends_on:
      - database
    command: ["./setup/wait-for-postgres.sh", "localhost:5432", "--", "node", "src"]
  database:
    image: postgres
    environment:
      - "POSTGRES_USER=postgres"
      - "POSTGRES_PASSWORD=postgres"
      - "POSTGRES_DB=tide_server"
    ports:
      - 5432:5432

The problem is that when I run docker-compose up I get the following error:

server_1    | Postgres is unavailable - sleeping
server_1    | psql: could not translate host name "192.168.64.2:5432" to address: Name or servi
ce not known
server_1    | Postgres is unavailable - sleeping
server_1    | psql: could not translate host name "192.168.64.2:5432" to address: Name or servi
ce not known
server_1    | Postgres is unavailable - sleeping
server_1    | psql: could not translate host name "192.168.64.2:5432" to address: Name or servi
ce not known

Now I have tried setting the host as database, localhost, 0.0.0.0, and even the containers IP but nothing works, I have no idea what it should be or how to debug it, I am not 100% sure how docker-compose links the containers.

Answer 1

do not use depends_on. try it with "links"

    version: '2'
    services:
      server:
        build: .
        ports:
          - 3030:3030
        links:
          - database
        #environment could be usefull too
        environment:
            DATABASE_HOST: database
        command: ["./setup/wait-for-postgres.sh", "localhost:5432", "--", "node", "src"]
      database:
        image: postgres
        environment:
          - "POSTGRES_USER=postgres"
          - "POSTGRES_PASSWORD=postgres"
          - "POSTGRES_DB=tide_server"
        ports:
          - 5432:5432

for more informations https://docs.docker.com/compose/compose-file/#links