docker-compose multiple postgres databases

Question

I try to up several postgres databases by writing docker-compose file and create database when container is up. The problem is - that database is not created

I do not understand why it doesn't create. But if i try to up only one postgres it works. What i missed?

works well:

services:
  tenant_first:
    image: postgres
    restart: always
    volumes:
      - pgdata:/var/lib/postgresql/data/
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_DB=tenant_first
    ports:
      - 50005:5432

Doesn't work (not create database if more than one recording)

services:
  tenant_first:
    image: postgres
    restart: always
    volumes:
      - pgdata:/var/lib/postgresql/data/
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_DB=tenant_first
    ports:
      - 50005:5432

  tenant_second:
    image: postgres
    restart: always
    volumes:
      - pgdata:/var/lib/postgresql/data/
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_DB=tenant_second
    ports:
      - 50008:5432

I did it works adding volumes

volumes:
  pgdata:
  pgdata2:

Answer 1

Here the full workable solution what i did

version: '3.3'

services:
  tenant_first:
    image: postgres
    restart: always
    volumes:
      - pgdata:/var/lib/postgresql/data/
      - ./sql/initdb.sh:/docker-entrypoint-initdb.d/initdb.sh
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres

    ports:
      - 50005:5432
#
  tenant_fours:
    image: postgres
    restart: always
    volumes:
      - pgdata2:/var/lib/postgresql/data/
      - ./sql/initdb_f.sh:/docker-entrypoint-initdb.d/initdb_f.sh
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres
    ports:
      - 50008:5432

networks:
  default:
    external:
      name: flask_mu_one_dbs

volumes:
  pgdata:
  pgdata2:

initdb.sh

#!/bin/bash
psql -U postgres
psql -c "create database tenant_first"

initdb_f.sh

#!/bin/bash
psql -U postgres
psql -c "create database tenant_fours"