Postgresql Docker Compose和Postgres:名称未解析

在Docker中，我正在尝试配置Postgres，将其安装到另一个容器中并运行，然后将其链接到我的

用户

服务，设置为以下结构：

docker-compose-dev.yml
services/
        users/
             manage.py
             Dockerfile-dev
             entrypoint.sh
             project/
                    __init__.py
                    config.py
                    db/
                      create.sql
                      Dockerfile

docker-compose-dev.yml

version: '3.7'

services:

  users:
    build:
      context: ./services/users
      dockerfile: Dockerfile-dev
    volumes:
      - './services/users:/usr/src/app'
    ports:
      - 5001:5000
    environment:
      - FLASK_APP=project/__init__.py
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@users-db:5432/users_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@users-db:5432/users_test  
    depends_on:  
      - users-db

  users-db:  
    build:
      context: ./services/users/project/db
      dockerfile: Dockerfile
    ports:
      - 5435:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres

CREATE DATABASE users_prod;
CREATE DATABASE users_dev;
CREATE DATABASE users_test;

Dockerfile dev

# base image
FROM python:3.7.2-alpine

# install dependencies
RUN apk update && \
    apk add --virtual build-deps gcc python-dev musl-dev && \
    apk add postgresql-dev && \
    apk add netcat-openbsd

# set working directory
WORKDIR /usr/src/app

# add and install requirements
COPY ./requirements.txt /usr/src/app/requirements.txt
RUN pip install -r requirements.txt

# add entrypoint.sh
COPY ./entrypoint.sh /usr/src/app/entrypoint.sh
RUN chmod +x /usr/src/app/entrypoint.sh

# add app
COPY . /usr/src/app

# run server
CMD ["/usr/src/app/entrypoint.sh"]

在这里，我试图通过向容器中的

“docker entrypoint initdb.d”

目录添加一个SQL文件来扩展官方Postgres映像

Dockerfile

# base image
FROM postgres:11.1-alpine

# run create.sql on init
ADD create.sql /docker-entrypoint-initdb.d

create.sql

version: '3.7'

services:

  users:
    build:
      context: ./services/users
      dockerfile: Dockerfile-dev
    volumes:
      - './services/users:/usr/src/app'
    ports:
      - 5001:5000
    environment:
      - FLASK_APP=project/__init__.py
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@users-db:5432/users_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@users-db:5432/users_test  
    depends_on:  
      - users-db

  users-db:  
    build:
      context: ./services/users/project/db
      dockerfile: Dockerfile
    ports:
      - 5435:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres

CREATE DATABASE users_prod;
CREATE DATABASE users_dev;
CREATE DATABASE users_test;

由于“users”服务不仅依赖于容器的启动和运行，而且还依赖于实际的Postgres实例的启动和正常运行，因此我在“users”中添加了一个

entrypoint.sh

文件：

entrypoint.sh

#!/bin/sh

echo "Waiting for postgres..."

while ! nc -z users-db 5432; do
  sleep 0.1
done

echo "PostgreSQL started"

python manage.py run -h 0.0.0.0

管理.py

from flask.cli import FlaskGroup
from project import app, db

cli = FlaskGroup(app)
@cli.command('recreate_db')
def recreate_db():
    db.drop_all()
    db.create_all()
    db.session.commit()
if __name__ == '__main__':
    cli()

import os  

class BaseConfig:
    """Base configuration"""
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False  

class DevelopmentConfig(BaseConfig):
    """Development configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') 

class TestingConfig(BaseConfig):
    """Testing configuration"""
    TESTING = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_TEST_URL')  

class ProductionConfig(BaseConfig):
    """Production configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')  

config.py

from flask.cli import FlaskGroup
from project import app, db

cli = FlaskGroup(app)
@cli.command('recreate_db')
def recreate_db():
    db.drop_all()
    db.create_all()
    db.session.commit()
if __name__ == '__main__':
    cli()

import os  

class BaseConfig:
    """Base configuration"""
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False  

class DevelopmentConfig(BaseConfig):
    """Development configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') 

class TestingConfig(BaseConfig):
    """Testing configuration"""
    TESTING = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_TEST_URL')  

class ProductionConfig(BaseConfig):
    """Production configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')  

我使用以下工具运行并成功构建它：

docker-compose -f docker-compose-dev.yml up -d --build

但我有一些网络问题。如果我跑步：

docker-compose -f docker-compose-dev.yml logs

我得到：

Attaching to dev2_users_1
users_1  | Waiting for postgres...
users_1  | nc: getaddrinfo: Name does not resolve
users_1  | nc: getaddrinfo: Name does not resolve
users_1  | nc: getaddrinfo: Name does not resolve
users_1  | nc: getaddrinfo: Name does not resolve
users_1  | nc: getaddrinfo: Name does not resolve
(...)

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
6ca5718c9867        dev2_users          "/usr/src/app/entryp…"   2 minutes ago       Up 2 minutes        0.0.0.0:5001->5000/tcp   dev2_users_1

---

上面的代码中缺少了什么？

您需要在

Dockerfile dev

中安装

绑定工具
，因为
名称无法解决问题：

apk add bind-tools 

测试：

PostgreSQL的启动通常相当健谈；在日志输出中，您是否确实看到了
users-db_1
中的任何内容？不，我什么也看不到…我认为问题在于
users-db_1
启动失败，请执行
docker-compose-f docker-compose-dev.yml up
而不执行
-d
并查找
users-db_1
中的日志。尝试过了。由于
而在
entrypoint.sh
中，我得到了一个无限循环。没有用户的迹象-db-1。还有其他日志命令吗？