CODEWITHSUNDEEP
mysqldjangodockerdocker-compose
Dave
Dave

Reputation: 19150

How do I connect my docker Django instance to my docker mysql instance?

I'm running Docker on Mac High Sierra. I want to run Docker container to house both my Django instances and MySql instances. I have the following docker-compose.yml file ...

version: '3'

services:
  web:
    restart: always
    build: ./web
    ports:           # to access the container from outside
      - "8000:8000"
    env_file: .env
    environment:
      DEBUG: 'true'
    command: /usr/local/bin/gunicorn maps.wsgi:application -w 2 -b :8000

  apache:
    restart: always
    build: ./apache/
    ports:
      - "80:80"
    #volumes:
    #  - web-static:/www/static
    links:
      - web:web

  mysql:
    restart: always
    image: mysql:5.7
    environment:
      MYSQL_DATABASE: 'maps_data'
      # So you don't have to use root, but you can if you like
      MYSQL_USER: 'chicommons'
      # You can use whatever password you like
      MYSQL_PASSWORD: 'password'
      # Password for root access
      MYSQL_ROOT_PASSWORD: 'password'
    ports:
      - "3406:3406"
    volumes:
      - my-db:/var/lib/mysql

volumes:
  my-db:

The ".env" file I set up looks like this ...

DB_NAME=maps_data
DB_USER=chicommons
DB_PASS=password
DB_SERVICE=mysql
DB_PORT=3406

In my web (Django) instance, I have set my settings.py db thusly ...

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': os.environ['DB_NAME'],
        'USER': os.environ['DB_USER'],
        'PASSWORD': os.environ['DB_PASS'],
        'HOST': os.environ['DB_SERVICE'],
        'PORT': os.environ['DB_PORT']
    }
}

However, when I run "docker-compose up," I get the following errors complaining about not being able to connect to the database ...

web_1     | Traceback (most recent call last):
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
web_1     |     self.connect()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 194, in connect
web_1     |     self.connection = self.get_new_connection(conn_params)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 236, in get_new_connection
web_1     |     return Database.connect(**conn_params)
web_1     |   File "/usr/local/lib/python3.7/site-packages/MySQLdb/__init__.py", line 84, in Connect
web_1     |     return Connection(*args, **kwargs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/MySQLdb/connections.py", line 179, in __init__
web_1     |     super(Connection, self).__init__(*args, **kwargs2)
web_1     | MySQLdb._exceptions.OperationalError: (2002, "Can't connect to MySQL server on 'mysql' (115)")
web_1     | 
web_1     | The above exception was the direct cause of the following exception:
web_1     | 
web_1     | Traceback (most recent call last):
web_1     |   File "manage.py", line 21, in <module>
web_1     |     main()
web_1     |   File "manage.py", line 17, in main
web_1     |     execute_from_command_line(sys.argv)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
web_1     |     utility.execute()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/__init__.py", line 365, in execute
web_1     |     self.fetch_command(subcommand).run_from_argv(self.argv)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/base.py", line 288, in run_from_argv
web_1     |     self.execute(*args, **cmd_options)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/base.py", line 332, in execute
web_1     |     self.check()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/base.py", line 364, in check
web_1     |     include_deployment_checks=include_deployment_checks,
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/management/base.py", line 351, in _run_checks
web_1     |     return checks.run_checks(**kwargs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/checks/registry.py", line 73, in run_checks
web_1     |     new_errors = check(app_configs=app_configs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/core/checks/model_checks.py", line 27, in check_all_models
web_1     |     errors.extend(model.check(**kwargs))
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/base.py", line 1200, in check
web_1     |     errors.extend(cls._check_fields(**kwargs))
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/base.py", line 1272, in _check_fields
web_1     |     errors.extend(field.check(**kwargs))
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 894, in check
web_1     |     errors = super().check(**kwargs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 206, in check
web_1     |     errors.extend(self._check_backend_specific_checks(**kwargs))
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 303, in _check_backend_specific_checks
web_1     |     return connections[db].validation.check_field(self, **kwargs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/validation.py", line 21, in check_field
web_1     |     field_type = field.db_type(self.connection)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 648, in db_type
web_1     |     return connection.data_types[self.get_internal_type()] % data
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/utils/functional.py", line 36, in __get__
web_1     |     res = instance.__dict__[self.name] = self.func(instance)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 133, in data_types
web_1     |     if self.features.supports_microsecond_precision:
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/utils/functional.py", line 36, in __get__
web_1     |     res = instance.__dict__[self.name] = self.func(instance)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/mysql/features.py", line 65, in supports_microsecond_precision
web_1     |     return self.connection.mysql_version >= (5, 6, 4)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/utils/functional.py", line 36, in __get__
web_1     |     res = instance.__dict__[self.name] = self.func(instance)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 345, in mysql_version
web_1     |     with self.temporary_connection() as cursor:
web_1     |   File "/usr/local/lib/python3.7/contextlib.py", line 112, in __enter__
web_1     |     return next(self.gen)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 576, in temporary_connection
web_1     |     cursor = self.cursor()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 255, in cursor
web_1     |     return self._cursor()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 232, in _cursor
web_1     |     self.ensure_connection()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
web_1     |     self.connect()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/utils.py", line 89, in __exit__
web_1     |     raise dj_exc_value.with_traceback(traceback) from exc_value
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
web_1     |     self.connect()
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/base/base.py", line 194, in connect
web_1     |     self.connection = self.get_new_connection(conn_params)
web_1     |   File "/usr/local/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 236, in get_new_connection
web_1     |     return Database.connect(**conn_params)
web_1     |   File "/usr/local/lib/python3.7/site-packages/MySQLdb/__init__.py", line 84, in Connect
web_1     |     return Connection(*args, **kwargs)
web_1     |   File "/usr/local/lib/python3.7/site-packages/MySQLdb/connections.py", line 179, in __init__
web_1     |     super(Connection, self).__init__(*args, **kwargs2)
web_1     | django.db.utils.OperationalError: (2002, "Can't connect to MySQL server on 'mysql' (115)")

What's going on? How do I get my Django web docker instance to connect to my MySql docker instance?

Upvotes: 3

Views: 1008

Answers (2)

Germano Barcelos
Germano Barcelos

Reputation: 25

To use db's and other services, container to container, see links.

You took a mistake: "3406:3406". The first port is the host port and the second port is the service that is running inside the container, so mysql runs on 3306, therefore you have to change to "3406:3306".

If you have different services running like backend/frontend you should create networks between containers.

Upvotes: 0

J-Jacques M
J-Jacques M

Reputation: 1118

Maybe port mistake

version: '3'

services:
  web:
    ...
    links:  # <-- add this
      - mysql # <-- add this

  apache:
    ...

  mysql:
    ...
    ports:  # <-- add this
      - "3406:3306" # <-- change myslq port inside is 3306 not 3406


volumes:
  my-db:

Upvotes: 2

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