Postgres compose file

docker-compose.yml

version: "2"

services:
  db:
    image: postgres
    container_name: postgres_docker
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=mypassword
      - POSTGRES_DB=postgres
    ports:
      - "5432:5432"
    volumes:
      - pgdata:/var/lib/postgresql/data
    restart: always
volumes: 
  pgdata: