如何使用docker compose为使用postgres的Django应用正确配置卷？

我有一个使用Postgresql的停靠Django应用程序。在我将卷添加到docker compose文件之前，所有内容都会运行find，以便为DB提供持久数据存储

docker-compose.yml：

version: "3"

services: 
  app:
    build:
      context: .
    ports:
      - "8000:8000"
    volumes:
      - ./app:/app
    command: > 
      sh -c "python manage.py wait_for_db &&
             python manage.py migrate &&
             python manage.py runserver 0.0.0.0:8000"
    environment:
      - DB_HOST=db
      - DB_NAME=app
      - DB_USER=postgres
      - DB_PASS=dbpassword

    depends_on:
      - db

  db:
    image: postgres:10-alpine
    volumes:
      - ./postgres-data:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=app
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=dbpassword
    ports:
      - "5432:5432"

此处的错误消息：

django.db.utils.OperationalError: could not connect to server: Connection refused
app_1  |    Is the server running on host "db" (172.26.0.2) and accepting
app_1  |    TCP/IP connections on port 5432?
app_1  |
recipe-api_app_1 exited with code 1
db_1   | 2019-08-31 22:52:35.969 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
db_1   | 2019-08-31 22:52:35.969 UTC [1] LOG:  listening on IPv6 address "::", port 5432
db_1   | 2019-08-31 22:52:35.972 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
db_1   | 2019-08-31 22:52:36.042 UTC [18] LOG:  database system was shut down at 2019-08-31 22:41:04 UTC
db_1   | 2019-08-31 22:52:36.055 UTC [1] LOG:  database system is ready to accept connections

一旦你为docker compose添加了卷，我就会一直收到这个错误，如果没有卷，一切都会正常运行

编辑：wait_for_db命令：

   def handle(self, *args, **options):
        """Handle the command"""
        self.stdout.write('Waiting for database...')
        db_conn = None
        while not db_conn:
            try:
                db_conn = connections['default']
            except OperationalError:
                self.stdout.write('Database unavailable, waiting 1 second...')
                time.sleep(1)

        self.stdout.write(self.style.SUCCESS('Database available!'))

---

看起来数据库正在正确启动，但应用程序在准备就绪之前需要连接；我会调试为什么你的

wait_for_db

不起作用。@DavidMaze我编辑了这个问题，添加了我的

wait_for_db

命令，我不明白为什么它会在添加了卷的情况下起作用，但在添加卷的情况下却不起作用postgres@DavidMaze这是

wait_for_db

脚本的问题，已修复，谢谢