我在连接使用docker-compose启动的mysql docker容器时遇到一些问题。这是一篇很长的帖子（对不起！）。

这是我的docker-compose.yml文件：

db:
  image: mysql:5.7
  ports:
    - "3306:3306" # I have tried both ports and expose "3306". Still doesn't work 
  environment:
    - MYSQL_ROOT_PASSWORD="secret"
    - MYSQL_USER="django"
    - MYSQL_PASSWORD="secret"
    - MYSQL_DATABASE="myAppDB"

然后：

$> docker-compose build
db uses an image, skipping #expected!
$> docker-compose up
<<LOTS OF OUTPUT>>

OK，所以现在我有一个正在运行的Docker容器运行器mysql：5.7。大！还是？在django应用中进行测试时，出现操作错误，提示不允许用户连接数据库。好吧，那么也许是我的django吗？

$> docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
c7216f99ca0f        mysql:5.7           "docker-entrypoint.sh"   3 minutes ago       Up 3 minutes        0.0.0.0:3306->3306/tcp   sharpfin_db_1

$> docker-machine ip dev
192.168.99.100
$> mysql -h 192.168.99.100 -P 3306 -u django -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'django'@'192.168.99.1' (using password: YES)

好的，也许这与连接到docker-compose容器有关吗？如果我尝试从docker容器内部进行连接怎么办？

$> docker exec -it c7216f99ca0f /bin/bash
root@c7216f99ca0f:/#
root@c7216f99ca0f:/# mysql -u django -p                                                                                                                                                           
Enter password: 
ERROR 1045 (28000): Access denied for user 'django'@'localhost' (using password: YES)

好的，所以docker mysql不会让我连接，也不知道为什么。让我们看看当我尝试不使用docker-compose时会发生什么：

$> docker run --name run-mysql -e MYSQL_ROOT_PASSWORD="secret" -e MYSQL_USER="django" -e MYSQL_PASSWORD="secret" -e MYSQL_DATABASE="myAppDB" -p "3306:3306" mysql:5.7
<<LOTS OF OUTPUT SAME AS BEFORE>>

好的，现在我们有了一个容器，它使用相同的设置运行与以前相同的图像。（我认为这个断言可能不正确-docker-compose与docker run有所不同）。

$> docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
73071b929e82        mysql:5.7           "docker-entrypoint.sh"   3 minutes ago       Up 3 minutes        0.0.0.0:3306->3306/tcp   run-mysql

有我的容器（称为run-mysql）。让我们连接！

$> mysql -h 192.168.99.100 -P 3306 -u django -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.12 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| myAppDB            |
+--------------------+
2 rows in set (0.01 sec)

mysql>

好的。可以登录。这很奇怪…从容器内部怎么办？

$> docker exec -it 73071b929e82 /bin/bash
root@73071b929e82:/# mysql -u django -p                                                                                                                                                           
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.12 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| myAppDB            |
+--------------------+
2 rows in set (0.00 sec)

mysql>

好的，当我使用docker run启动时，我可以从容器的外部和内部登录，但不能使用docker-compose登录。这是怎么回事？docker-
compose必须在后台执行某些操作来更改数据库的初始化方式。

如果我也尝试以root用户使用，则上述所有内容都是完全相同的。因此，这不是django用户的权限问题。

任何想法如何解决这个问题？