docker-compose.yml

services:
  postgres:
    image: postgres-mongo-fdw
    build: .
    depends_on:
      - mongo
    ports:
      - 5432:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
    volumes:
      - postgres_data:/var/lib/postgresql/data
    configs:
      - source: postgres_init_script
        target: /docker-entrypoint-initdb.d/99-custom.sh

  db-admin:
    image: dpage/pgadmin4:8
    depends_on:
      - postgres
    ports:
      - 5433:80
    environment:
      - PGADMIN_DEFAULT_EMAIL=admin@example.org
      - PGADMIN_DEFAULT_PASSWORD=admin
    volumes:
      - postgres_admin_data:/var/lib/pgadmin
    configs:
      - source: postgres_password
        target: /run/secrets/password.txt
      - source: postgres_servers
        target: /pgadmin4/servers.json

  mongo:
    image: mongo
    ports:
      - 27017:27017
    environment:
      MONGO_INITDB_ROOT_USERNAME: admin
      MONGO_INITDB_ROOT_PASSWORD: admin
      MONGO_INITDB_DATABASE: app
    volumes:
      - mongo_data:/data/db
    configs:
      - source: mongo_init_script
        target: /docker-entrypoint-initdb.d/99-custom.js

  mongo-admin:
    image: mongo-express
    restart: always
    depends_on:
      - mongo
    ports:
      - 27018:8081
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: admin
      ME_CONFIG_MONGODB_ADMINPASSWORD: admin
      ME_CONFIG_MONGODB_URL: mongodb://admin:admin@mongo:27017
      ME_CONFIG_BASICAUTH: false

volumes:
  postgres_data:
  postgres_admin_data:
  mongo_data:

configs:
  postgres_servers:
    content: |
      {
        "Servers": {
          "1": {
            "Group": "postgres",
            "Name": "postgres",
            "Port": 5432,
            "Username": "postgres",
            "PassFile": "/run/secrets/password.txt",
            "Host": "postgres",
            "SSLMode": "prefer",
            "MaintenanceDB": "postgres"
          }
        }
      }
  postgres_password:
    content: postgres
  postgres_init_script:
    content: |
      #!/bin/bash
      set -e

      psql -v ON_ERROR_STOP=1 --username "$$POSTGRES_USER" --dbname "$$POSTGRES_DB" <<-EOSQL
        CREATE EXTENSION mongo_fdw;

        CREATE SERVER "mongo" FOREIGN DATA WRAPPER mongo_fdw OPTIONS (
          address 'mongo',
          port '27017',
          authentication_database 'admin'
        );

        CREATE USER MAPPING FOR postgres SERVER "mongo" OPTIONS (
          username 'admin',
          password 'admin'
        );

        CREATE FOREIGN TABLE items (
          _id name,
          name text,
          price float
        ) SERVER "mongo" OPTIONS (
          database 'app',
          collection 'items'
        );
      EOSQL
  mongo_init_script:
    content: |
      db.createCollection("items");
      db.items.insertMany([
        {
          _id: new ObjectId(),
          name: "Apples",
          price: 4.99
        },
        {
          _id: new ObjectId(),
          name: "Bananas",
          price: 9.99
        },
        {
          _id: new ObjectId(),
          name: "Tomatoes",
          price: 3.99
        },
      ]);