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Dockerized Django app and MySQL with docker-compose using .env

I would to run my Django project into a Docker container with its Database on another Docker container inside a Bebian
When i run my docker container, I have some errors. Like : Lost connection to MySQL server during query ([Errno 104] Connection reset by peer).
This command mysql > SET GLOBAL log_bin_trust_function_creators = 1 is very important because database's Django user create trigger.
Morever, I use a .env file used same for create DB image to store DB user and password. This path is settings/.env.
My code:
docker-compose.yml:
version: '3.3'
services:
db:
image: mysql:8.0.29
container_name: db_mysql_container
environment:
MYSQL_DATABASE: $DB_NAME
MYSQL_USER: $DB_USER
MYSQL_PASSWORD: $DB_PASSWORD
MYSQL_ROOT_PASSWORD: $DB_ROOT_PASSWORD
command: ["--log_bin_trust_function_creators=1"]
ports:
- '3306:3306'
expose:
- '3306'
api:
build: .
container_name: django_container
command: bash -c "pip install -q -r requirements.txt &&
python manage.py migrate &&
python manage.py runserver 0.0.0.0:8000"
volumes:
- .:/app
ports:
- '8000:8000'
depends_on:
- db
Dockerfile :
# syntax=docker/dockerfile:1
FROM python:3.9.14-buster
ENV PYTHONUNBUFFERED=1
RUN mkdir /app
WORKDIR /app
COPY requirements.txt /app/
RUN pip install -r requirements.txt
ADD . /app/
How to start my Django project ? Is possible to start only the DB container ?
What command i need execute and what changes i need to make, I'm novice with Docker ! So if you help me, please explains your commands and actions !
You can find this project on my GitHub
Thank !

To run dockerized django project.
Simply you can run below command:
docker-compose run projectname bash -c "python manage.py createsuperuser"
Above command is used for to create superuser

Postgres in Docker/ Django app does not work - OperationalError: could not connect to server: Connection refused

I have a Django app that runs locally with no problems.
Now, I want to get a docker image of my app but when I try to build it, it gives me the following error:
django.db.utils.OperationalError: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Cannot assign requested address
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
I am new on Django and Docker development and i was looking for similar questions but none answer solved my problem.
I'll show you my Dockerfile, I have copied the Postgres commands from another project that does work:
FROM python:3.8
RUN apt-get update
RUN mkdir /project
WORKDIR /project
RUN apt-get install -y vim
COPY requirements.txt /project/
RUN pip install -r requirements.txt
COPY . /project/
# Install postgresql
RUN apt install -y postgresql postgresql-contrib
RUN service postgresql start
# Run the rest of the commands as the ``postgres`` user created by the ``postgres-9.3`` package when it was ``apt-get installed``
USER postgres
# Create a PostgreSQL role
RUN /etc/init.d/postgresql start &&\
psql --command "CREATE USER admin WITH SUPERUSER PASSWORD 'passwd';" &&\
createdb -O admin plataforma
USER root
# setup postgresql
RUN sed -i "/^#listen_addresses/i listen_addresses='*'" /etc/postgresql/13/main/postgresql.conf
RUN sed -i "/^# DO NOT DISABLE\!/i # Allow access from any IP address" /etc/postgresql/13/main/pg_hba.conf
RUN sed -i "/^# DO NOT DISABLE\!/i host all all 0.0.0.0/0 md5\n\n\n" /etc/postgresql/13/main/pg_hba.conf
# running commands of my app
RUN python manage.py makemigrations accounts
RUN python manage.py sqlmigrate accounts 0001
RUN python manage.py migrate
RUN python manage.py inicializar
# Expose some ports
EXPOSE 22 5432 8080 8009 8000
# volumes
VOLUME ["/var/lib/postgresql/12/main"]
# Default command
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
Here is my requirements.txt file:
#requirements.txt
Django==3.2.8
djangorestframework==3.9.1
gunicorn==19.9.0
pandas==1.3.3
path==16.2.0
six==1.14.0
Pillow==7.0.0
psycopg2>=2.8
django-environ==0.8.1
Here is my settings.py file (the databases fragment):
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': env('POSTGRESQL_NAME'),
'USER': env('POSTGRESQL_USER'),
'PASSWORD': env('POSTGRESQL_PASS'),
'HOST': env('POSTGRESQL_HOST'),
'PORT': env('POSTGRESQL_PORT'),
}
}
And here is my .env file:
POSTGRESQL_NAME=plataforma
POSTGRESQL_USER=admin
POSTGRESQL_PASS=passwd
POSTGRESQL_HOST=localhost
POSTGRESQL_PORT=5432
DEBUG=True
Some people told me that I could make a docker-compose file so I erased the postgres install commands from Dockerfile and made this:
version: "3.3"
services:
db:
image: postgres
volumes:
- ./data/db:/var/lib/postgresql/data
ports:
- "5432:5432"
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
environment:
- POSTGRES_NAME=plataforma
- POSTGRES_USER=admin
- POSTGRES_PASSWORD=passwd
depends_on:
- db
But this doesn't work either.
Footnote: If I use the Django's default database (SQLite) and (obviously) erase postgress commands from Dockerfile, I can build the Docker image without problems, and, again, this app with postgres works good if I run it locally. So, something is happening with Docker + postgres and I don't know what to do.
Somebody can help me? Thank you!
Edit: I erased the migrations commands from Dockerfile and replaced environ var of POSTGRESQL_HOST to db and when I run $ sudo docker-compose run web python manage.py runserver . the image is created but the container not, and when I try to run a container with that image i get the following error:
django.db.utils.OperationalError: could not translate host name "db" to address: Name or service not known
Sorry my english, I still learning it too.
EDIT AGAIN: I finally solved this issue in this question
Thanks for the help!

While creating a superuser your command is
CREATE USER admin WITH SUPERUSER PASSWORD 'administrador'
And in your env file you are using passwd as password.
Change your env from
POSTGRESQL_PASS=passwd
To this
POSTGRESQL_PASS=administrador

Django and Postgres problems with dockerizing

Hello I can not dockerize my django app because I got an error -
listen tcp4 0.0.0.0:5433: bind: address already in use
From the other hand, when I "kill" 5433 port in ubuntu terminal I get this error
Is the server running on host "localhost" (::1) and accepting
web_1 | TCP/IP connections on port 5433?
What can I do to solve this problem and dockerize successfully my app?
Dockerfile
FROM python:3
RUN adduser --system --no-create-home django
ENV PYTHONUNBUFFERED=1
WORKDIR /code
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
ENV PYTHONPATH /code
EXPOSE 8000
USER django
CMD ["./main.py"]
docker-compose
version: "3"
services:
db:
image: postgres
volumes:
- ./data/db:/var/lib/postgresql/data
environment:
- POSTGRES_DB=fitshop
- POSTGRES_USER=fituser
- POSTGRES_PASSWORD=fitpass
ports:
- "5433:5433"
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
restart: always
ports:
- "8000:8000"
depends_on:
- db
settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'fitshop',
'USER': 'fituser',
'PASSWORD': 'fitpass',
'HOST': 'localhost',
'PORT': '5433',
}
}

You should use "db" as host here. In a docker-compose setup each service is started in a separate Container and the /etc/hosts config of all containers is modified so, that each container can find the other containers via the service names.

I`ve got it!. In 'localhost" port of postgres was 5433 but for 'db' as HOST it was default, 5432.

How can I set the best configurations for the project working with django, docker and mysql?

I was reading an article in here which is about setting up project using docker, django and mysql together.
these are my files in project:
Dockerfile
FROM python:3.7
MAINTAINER masoud masoumi moghadam
ENV PYTHONUNBUFFERED 1
RUN mkdir /app
WORKDIR /app
ADD . /app
ADD requirements.txt /app/requirements.txt
RUN pip install --upgrade pip && pip install -r requirements.txt
Docker-compose
version: "3"
services:
app:
build:
context: .
ports:
- "8000:8000"
volumes:
- ./app:/app
command: >
sh -c "python manage.py runserver 0.0.0.0:8000"
environment:
- DB_HOST=localhost
- DB_NAME=contact_list
- DB_USER=root
- DB_PASS=secretpassword
depends_on:
- db
db:
image: mysql:5.7
environment:
- MYSQL_DATABASE=contact_list
- MYSQL_USER=root
- MYSQL_PASSWORD=secretpassword
requirements
Django>=2.0,<3.0
djangorestframework<3.10.0
mysqlclient==1.3.13
django-mysql==2.2.0
and also this settings in my setting.py:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'HOST': os.environ.get('DB_HOST'),
'NAME': os.environ.get('DB_NAME'),
'USER': os.environ.get('DB_USER'),
'PASSWORD': os.environ.get('DB_PASS')
}
}
When I use docker-compose build I face no problem and everything is just fine. Then I run service mysql start. I can assure that mysql service is in run and works because I have access to datasets. The problem occurs when I do the migration using this command docker-compose run app sh -c "python manage.py makemigrations core" I get this error:
django.db.utils.OperationalError: (2002,
"Can't connect to local MySQL server through socket
'/var/run/mysqld/mysqld.sock' (2)")
When I change localhost to 127.0.0.1 I get this error:
django.db.utils.OperationalError:
(2002, "Can't connect to MySQL
server on '127.0.0.1' (115)")
I spent 20 hours looking for the best possible configuration for these technologies, But I still can't figure out anything. I also used python-alpine but I still could not find it useful for project because I had the same mysql dependencies problem when I was trying to do docker build. Does anybody have the same experience? I would appreciate if you could help me here.

Your problem is that you use localhost as the host of mysql in django's config.
But docker containers have their own IP, they are not localhost.
So first in your docker-compose file, name your containers :
db:
image: mysql:5.7
container_name: db
...
Then in your django settings, set your db HOST to your db container name : "db" :
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'HOST': 'db',
'PORT' : 3306, # (?)
...
Also you are missing the db 'PORT' in django settings, I think that for Mysql it is 3306 (I've added it above).

According to this beautifully organized article, I found out this configurations will have no issues running on a server(changed mysql service to postgress service):
Dockerfile
# pull official base image
FROM python:3.8.0-alpine
# set work directory
WORKDIR /usr/src/app
# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
# install psycopg2 dependencies
RUN apk update \
&& apk add postgresql-dev gcc python3-dev musl-dev
# install dependencies
RUN pip install --upgrade pip
COPY requirements.txt /usr/src/app/requirements.txt
RUN pip install -r requirements.txt
# copy entrypoint.sh
COPY entrypoint.sh /usr/src/app/entrypoint.sh
# copy project
COPY . /usr/src/app/
# run entrypoint.sh
ENTRYPOINT ["/usr/src/app/entrypoint.sh"]
Docker-compose.yml
version: '3.7'
services:
web:
build: app
# container_name: web
command: python manage.py runserver 0.0.0.0:8000
restart: always
volumes:
- ./app/:/usr/src/app/
ports:
- 8000:8000
env_file:
- .env.dev
depends_on:
- db
db:
image: postgres:12.0-alpine
# container_name: postgres
restart: always
volumes:
- postgres_data:/var/lib/postgresql/data/
environment:
- POSTGRES_USER=user
- POSTGRES_PASSWORD=123456
- POSTGRES_DB=contact_list
requirements
Django==2.2.6
gunicorn==19.9.0
djangorestframework>=3.9.2,<3.10.0
psycopg2-binary==2.8.3
settings
DATABASES = {
'default': {
'ENGINE': os.environ.get('SQL_ENGINE', "django.db.backends.sqlite3"),
'NAME': os.environ.get("SQL_DB_NAME", os.path.join(BASE_DIR, "db.sqlite3")),
'USER': os.environ.get("SQL_USER", "user"),
'PASSWORD': os.environ.get("SQL_PASSWORD", "password"),
'HOST': os.environ.get("SQL_HOST", "localhost"),
'PORT': os.environ.get("SQL_PORT", "5432"),
}
}
I added a file named as .env.dev which is for better access to environment variables:
DEBUG=1
SECRET_KEY=123456
DJANGO_ALLOWED_HOSTS=localhost 127.0.0.1 [::1]
SQL_ENGINE=django.db.backends.postgresql
SQL_HOST=db
SQL_DB_NAME=contact_list
SQL_USER=user
SQL_PASSWORD=123456
SQL_PORT=5432
DATABASE=postgres

first try to login to mysql with provided credentials
docker exec -it <CONTAINER_ID> /bin/sh
Inside the docker please login to mysql via command line
mysql -uroot -psecretpassword

Running Wagtail site with Docker

I'm trying to convert an existing Wagtail site to run with Docker. I have created the image and then run the container, but I'm unable to connect in the browser window. Getting 0.0.0.0 didn’t send any data. ERR_EMPTY_RESPONSE.
Dockerfile:
FROM python:3.6
RUN mkdir /app
WORKDIR /app
COPY ./ /app
RUN pip install --no-cache-dir -r /app/requirements/base.txt
RUN mkdir -p -m 700 /app/static
RUN mkdir -p -m 700 /app/media
ENV DJANGO_SETTINGS_MODULE=mysite.settings.dev DJANGO_DEBUG=on
ENV SECRET_KEY=notsosecretkey
ENV DATABASE_URL=postgres://none
ENV SENDGRID_KEY=sendgridkey
EXPOSE 8080
RUN chmod +x /app/entrypoint.sh \
&& chmod +x /app/start-app.sh
RUN python manage.py collectstatic --noinput
ENTRYPOINT ["/app/entrypoint.sh"]
CMD ["/app/start-app.sh"]
docker-compose.yml:
version: '2'
services:
db:
environment:
POSTGRES_DB: app_db
POSTGRES_USER: app_user
POSTGRES_PASSWORD: changeme
restart: always
image: postgres:9.6
expose:
- "5432"
ports:
- "5432:5432"
app:
container_name: mysite_dev
build:
context: .
dockerfile: Dockerfile
depends_on:
- db
links:
- db:db
volumes:
- .:/app
ports:
- "8080:8080"
environment:
DATABASE_URL: postgres://app_user:changeme#db/app_db
command: python manage.py runserver 0.0.0.0:8080
entrypoint.sh:
#!/bin/sh
set -e
exec "$#"
start-app.sh:
#!/bin/sh
python manage.py runserver 0.0.0.0:8080
dev.py settings file:
from .base import *
DEBUG = True
for template_engine in TEMPLATES:
template_engine['OPTIONS']['debug'] = True
ALLOWED_HOSTS = (
'0.0.0.0',
)
DATABASES = {
'default': db_cache_url.config('DATABASE_URL', extra={'CONN_MAX_AGE': 0, 'ENGINE': 'django.db.backends.postgresql_psycopg2', 'NAME': 'mysite', 'HOST': 'localhost', 'PORT': '5432'}),
}
STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.StaticFilesStorage'
WSGI_APPLICATION = 'mysite.wsgi.application'
try:
from .local import *
except ImportError:
pass
I run docker run -p 8080:8080 app:latest and it works when I run docker ps showing that it's at 0.0.0.0:8080->8080/tcp, but when I go to 0.0.0.0:8080 in the browser window, I get the error. If I remove the DATABASES setting, I see Django errors loading, but then I'm getting settings.DATABASES is improperly configured. Please supply the NAME value. so I think it needs to be there. What am I missing?