No connection to postgres from my application

Docker Engine Compose
1

I have my simple app in C# that connect with postgreSQL.
I would like to create image with this app and just run with docker.

Everything is ok when I use:

$ docker build
$ docker run postgres
$ docker run my_app

Additionally, there is everything ok, when I use compose from application directory:

$ docker-compose build
$ docker-compose up

But is there any chance for use docker-compose for image that I built previous?

I would like to publish this image to my repo and somebody else from my team just download and run this image (app + database).

When I do compose-build and next compose run my_app I have exception during connecting to database:

dbug: Npgsql.NpgsqlConnection[3]
      Opening connection to database 'POSTGRES_USER' on server 'tcp://postgres:5432'.

Unhandled Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.AggregateException: One or more errors occurred. (No such device or address) ---> System.Net.Internals.SocketExceptionFactory+ExtendedSocketException: No such device or address

My current docker-compose.yml file:

version: '2'

services:

  web:
    container_name: 'postgrescoreapp'
    image: 'postgrescoreapp'
    build:
      context: .
      dockerfile: Dockerfile
    volumes:
      - .:/var/www/postgrescoreapp
    ports:
     - "5001:5001"
    depends_on:
     - "postgres"
    networks:
      - postgrescoreapp-network

  postgres:
    container_name: 'postgres'
    image: postgres
    environment:
      POSTGRES_PASSWORD: password
    networks:
      - postgrescoreapp-network

networks:
  postgrescoreapp-network:
    driver: bridge