Django unable to connect to database. - mysql

Question

I am attempting to create a dev environment for my company's app using docker. For some reason I am able to connect to the database if I use docker run web "bash" then run mysql from the shell, but Django wont connect. The Dockerfile for the web/worker nodes looks like:
FROM python:2.7
ENV PYTHONUNBUFFERED 1
ENV DOCKER 1
ENV REDIS_HOST "redis"
ENV CASSANDRA_HOST "cassandra"
RUN mkdir /code
WORKDIR /code
ADD . /code/
RUN pip install --default-timeout=100 numpy==1.9.1
RUN pip install --default-timeout=100 scipy==0.15.1
RUN pip install --default-timeout=100 -r requirements_docker.txt
#RUN python /code/app/manage.py migrate
And the docker-compose file looks like this:
version: "2"
services:
cassandra:
image:
cassandra:latest
redis:
image:
redis:latest
db:
image: mysql
environment:
MYSQL_DATABASE: appdb
MYSQL_USER: dbuser
MYSQL_PASSWORD: dbpass
web:
build: .
command: python app/manage.py runserver 0.0.0.0:8000
environment:
DOCKER: 1
DATABASE_HOST: db
DATABASE_NAME: appdb
DATABASE_USER: dbuser
DATABASE_PASSWORD: dbpass
REDIS_HOST: redis
CASSANDRA_HOST: cassandra
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db
- redis
- cassandra
worker:
build: .
environment:
DOCKER: 1
DATABASE_HOST: db
DATABASE_NAME: appdb
DATABASE_USER: dbuser
DATABASE_PASSWORD: dbpass
REDIS_HOST: redis
CASSANDRA_HOST: cassandra
command: python /code/app/manage.py celery worker -Q celery,offline,periodic --broker=redis://redis:6379/4
depends_on:
- db
- redis
- cassandra
Finally the database settings are (consolidated from multiple settings files):
if not os.environ.has_key('DOCKER'):
DATABASES = {
"default": {
'ENGINE': 'django.db.backends.mysql',
'OPTIONS': {
'read_default_file': os.path.join(PROJECT_ROOT, 'mysql.cnf'),
"init_command": "SET foreign_key_checks = 0;",
},
}
}
else: # Using Docker
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': os.environ['DATABASE_NAME'],
'USER': os.environ['DATABASE_USER'],
'PASSWORD': os.environ['DATABASE_PASSWORD'],
'HOST': os.environ["DATABASE_HOST"],
'PORT': '5432',
'OPTIONS': {
'init_command': "SET foreign_key_checks = 0;"
}
}
}
if 'test' in sys.argv:
SLAVE_DATABASES = []
elif os.environ.has_key('DOCKER'):
DATABASES['replica_1'] = {
'ENGINE': 'django.db.backends.mysql',
'NAME': os.environ['DATABASE_NAME'],
'USER': os.environ['DATABASE_USER'],
'PASSWORD': os.environ['DATABASE_PASSWORD'],
'HOST': os.environ["DATABASE_HOST"],
'PORT': '5432',
'OPTIONS': {
"init_command": "SET foreign_key_checks = 0;"
}
}
SLAVE_DATABASES = ['replica_1', ]
DATABASE_ROUTERS = ('multidb.PinningMasterSlaveRouter',)
MIDDLEWARE_CLASSES = ['multidb.middleware.PinningRouterMiddleware', ] + settings.MIDDLEWARE_CLASSES
else:
DATABASES["replica_1"] = {
'ENGINE': 'django.db.backends.mysql',
'OPTIONS': {
'read_default_file': os.path.join(settings.PROJECT_ROOT, 'mysql.cnf'),
"init_command": "SET foreign_key_checks = 0;",
},
'TEST': {
'MIRROR': 'default',
},
}
SLAVE_DATABASES = ['replica_1', ]
DATABASE_ROUTERS = ('multidb.PinningMasterSlaveRouter',)
MIDDLEWARE_CLASSES = ['multidb.middleware.PinningRouterMiddleware', ] + settings.MIDDLEWARE_CLASSES
if os.environ.has_key("DOCKER"):
from cassandra import ConsistencyLevel
DATABASES['cassandra'] = {
'ENGINE': 'django_cassandra_engine',
'NAME': 'verificient_local',
'TEST_NAME': 'test_verificient_local',
'HOST': os.environ['CASSANDRA_HOST'],
'OPTIONS': {
'replication': {
'strategy_class': 'SimpleStrategy',
'replication_factor': 1
},
'connection': {
'consistency': ConsistencyLevel.LOCAL_ONE,
'retry_connect': True
},
'session': {
'default_timeout': 30,
'default_fetch_size': 10000
}
}
}
The weird part is that even though running python manage.py migrate returns an error (django.db.utils.OperationalError: (2003, "Can't connect to MySQL server on 'db' (111)")) I am able to connect to the database with no issue using the command mysql -h$DATABASE_HOST -u$DATABASE_USER -p$DATABASE_PASSWORD $DATABASE_NAME
What could be going wrong in my django setup?

Answer 1

MySQL default port is 3306, so change:
'PORT': '5432',
to
'PORT': '3306',
It does work manually with your mysql command because that command uses the correct port by default