Django model changes not reflected on Postgres Docker container - django

Question

I have a Django-Postgres app deployed with Docker. I have two docker containers web and dband one docker volume for persistent storage.
My docker-compose.yml file:
version: '2'
services:
db:
image: postgres
ports:
- '5432:5432'
volumes:
- 'postgres:/var/lib/postgresql/data'
env_file: .env
web:
build: .
command: ./start.sh
volumes:
- .:/app
ports:
- "8000:8000"
depends_on:
- db
env_file: .env
volumes:
postgres:
I made a change in my django model.py:
class Meeting(models.Model):
[...]
participants = models.CharField(max_length=200)
to
class Meeting(models.Model):
[...]
user_participants = models.CharField(max_length=200)
However, this change is not reflected on my Django app and I get the following error:
column call_meeting.user_participants does not exist
I ran:
python manage.py makemigrations call
python manage.py migrate
Then I tried to delete Django migrations and re-run the above commands. I have tried to re-run docker-compose build but none of them worked.
Why does this happen? Should I change the column names with raw SQL?

Answer 1

From your question and comments, I get the impression that your django is not using the correct database. Or more probably (rather than two co-existing db instances), the database is recreated on every docker restart even though the docker-compose file does not look like it.
We are using a similar setup which works for us, but the data volume is mounted differently - so that might be the issue here:
- ./pgdata:/var/lib/postgresql/data/pgdata
settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('POSTGRES_DB', 'my_db'),
'HOST': os.environ.get('POSTGRES_HOST', 'localhost'),
'PORT': os.environ.get('POSTGRES_PORT', '5432'),
'USER': os.environ.get('POSTGRES_USER', 'my_user'),
'PASSWORD': os.environ.get('POSTGRES_PASSWORD', 'my_password'),
'CONN_MAX_AGE': 120
}
}
docker-compose.yml
version: '2'
services:
postgres:
image: postgres:9.5
volumes:
- ./pgdata:/var/lib/postgresql/data/pgdata
environment:
- PGDATA=/var/lib/postgresql/data/pgdata
- POSTGRES_DB=<name> #django.settings.DATABASES['default']['NAME']
- POSTGRES_USER=<user> #django.settings.DATABASES['default']['USER']
- POSTGRES_PASSWORD=<password> #django.settings.DATABASES['default']['PASSWORD']
ports:
- 5432:5432
web:
depends_on:
- postgres
volumes:
- .:/app
environment:
- POSTGRES_HOST=postgres
- POSTGRES_DB=<host> # no need if settings.py is fine
- POSTGRES_USER=<user> # no need if settings.py is fine
- POSTGRES_PASSWORD=<password> # no need if settings.py is fine
build: .
ports:
- 8000:8000
command: ./start.sh