Docker SQLSTATE[08006] for pgsql service only from php service

Question

Not sure if my title is accurate, but here's my issue. I am running a basic laravel site on Docker and cannot get the site itself to connect to the PostgreSQL service. I will post my docker-compose.yml below. When i run php artisan migrate i get no errors and it all works. I can even use my Postico PostgreSQL client to connect to the DB and run queries. But, when i try and connect to the DB from the site, it errors out saying this:

SQLSTATE[08006] [7] could not connect to server: Connection refused Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5433?

Here are my PostgreSQL client settings (which DO work):

Host: 127.0.0.1
Port: 5433
User: homestead
Password: homestead
Database: homestead

I have been messing around with different settings and things so here is my docker-compose.yml, although i'm sure there are things i don't need in there:

version: '2'

services:
  php:
    image: jguyomard/laravel-php:7.2
    build:
      context: .
      dockerfile: infrastructure/php/Dockerfile
    volumes:
      - ./:/var/www/
      - $HOME/.composer/:$HOME/.composer/
    networks:
      - default
    links:
      - postgresql
      - redis

  nginx:
    image: jguyomard/laravel-nginx:1.13
    build:
      context: .
      dockerfile: infrastructure/nginx/Dockerfile
    ports:
      - 81:80
    networks:
      - default
    links:
      - postgresql
      - redis

  postgresql:
    image: postgres:9.6-alpine
    volumes:
      - pgsqldata:/var/lib/postgresql/data
    environment:
      - "POSTGRES_DB=homestead"
      - "POSTGRES_USER=homestead"
      - "POSTGRES_PASSWORD=homestead"
    ports:
      - "5433:5432"
    networks:
      - default

  redis:
    image: redis:4.0-alpine
    command: redis-server --appendonly yes
    ports:
      - "6379:6379"
    networks:
      - default

#  elastic:
#    image: elasticsearch:5.5-alpine
#    ports:
#        - "9200:9200"

volumes:
  pgsqldata:

networks:
  default:

Any thoughts on why the site can't connect to the DB?

My docker network ls output:

NETWORK ID      NAME               DRIVER        SCOPE
2bf85424f466    bridge             bridge        local
c29d413f768e    host               host          local
0bdf9db30cd8    none               null          local
f3d9cb028ae3    my-app_default     bridge        local

Answer 1

The error message ask Is the server running on host "127.0.0.1" but in your case PostgreSQL is running on a different docker container which is not 127.0.0.1 reference to php app so, change the server host to postgresql inside your php application.

And for the modified error, it is because that you have used port 5433 inside the php application which is the port of host machine which is for use outside the docker container (for host machine, that's why your Postico PostgreSQL client worked). But the port you have to use inside the docker network is 5432 change the server port to 5432 inside your php application.

And you have made the compose file complex by defining network in each host as default network. (You can follow this link for more details) If you don't have a requirement for that you don't need to do that as docker-compose will deploy all containers in single network.

And you don't need to use links they are deprecated. When multiple containers are in one docker-compose.yml file they are automatically deployed in a same single network.

So this simplified compose file will be recommended.

version: '2'

services:
  php:
    image: jguyomard/laravel-php:7.2
    build:
      context: .
      dockerfile: infrastructure/php/Dockerfile
    volumes:
      - ./:/var/www/
      - $HOME/.composer/:$HOME/.composer/

  nginx:
    image: jguyomard/laravel-nginx:1.13
    build:
      context: .
      dockerfile: infrastructure/nginx/Dockerfile
    ports:
      - 81:80

  postgresql:
    image: postgres:9.6-alpine
    volumes:
      - pgsqldata:/var/lib/postgresql/data
    environment:
      - "POSTGRES_DB=homestead"
      - "POSTGRES_USER=homestead"
      - "POSTGRES_PASSWORD=homestead"
    ports:
      - "5433:5432"

  redis:
    image: redis:4.0-alpine
    command: redis-server --appendonly yes
    ports:
      - "6379:6379"

#  elastic:
#    image: elasticsearch:5.5-alpine
#    ports:
#        - "9200:9200"

volumes:
  pgsqldata: