Django on Docker is starting up but browser gives empty response - python

For a simple app with Django, Python3, Docker on mac
Dockerfile
FROM python:3
ENV PYTHONUNBUFFERED=1
RUN mkdir /code
WORKDIR /code
COPY requirements.txt /code/
RUN python3 -m pip install -r requirements.txt
CMD python3 manage.py runserver
COPY . /code/
docker-compose.yml
version: "3.9"
services:
# DB
db:
image: mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: '****'
MYSQL_USER: '****'
MYSQL_PASSWORD: '****'
MYSQL_DATABASE: 'mydb'
ports:
- "3307:3306"
expose:
# Opens port 3306 on the container
- '3307'
volumes:
- $HOME/proj/sql/mydbdata.sql:/mydbdata.sql
# Web app
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db
Also, what I wanted is to execute the SQL the first time the image is created,
after that database should be mounted.
volumes:
- $HOME/proj/sql/mydbdata.sql:/mydbdata.sql
Looks like the Docker is starting but from my browser, I get this response
localhost didn’t send any data.
ERR_EMPTY_RESPONSE
what is that I am missing. Please help

Looks like your django project is running already when you create image. Since you use command option docker-compose.yml file, you don't need CMD command in Dockerfile in this case.
I would rewrite Dockerfile and docker-compose.yml as follows:
FROM python:3
ENV PYTHONUNBUFFERED 1
RUN mkdir /code
WORKDIR /code
COPY requirements.txt /code/
RUN python3 -m pip install -r requirements.txt
COPY . /code/
version: "3.9"
services:
db:
image: mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: '****'
MYSQL_USER: '****'
MYSQL_PASSWORD: '****'
MYSQL_DATABASE: 'mydb'
ports:
- "3307:3306" # make sure django project connects to 3306 port
volumes:
- $HOME/proj/sql:/docker-entrypoint-initdb.d
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db
A few things to point out.
When you run docker-compose up, you will probably see an error, because your django project will already be running even before db is initialised.
That's natural. So you need customized command or shell program to force django project to wait to try to connect db.
In my case I would use a custom command.
version: "3.9"
services:
db:
image: mysql:8
env_file:
- .env
command:
- --default-authentication-plugin=mysql_native_password
restart: always
ports:
- "3308:3306"
web:
build: .
command: >
sh -c "python manage.py wait_for_db &&
python manage.py makemigrations &&
python manage.py migrate &&
python manage.py runserver 0.0.0.0:8000"
volumes:
- .:/code
ports:
- "8001:8000"
depends_on:
- db
env_file:
- .env
Next, wait_for_db.py. This file is what I created in myapp/management/commands/wait_for_db.py. With this you postpone db connection until db is ready. This SO post has helped me a lot.
See Writing custom django-admin command for detail.
import time
from django.db import connection
from django.db.utils import OperationalError
from django.core.management.base import BaseCommand
class Command(BaseCommand):
"""Wait to connect to db until db is initialised"""
def handle(self, *args, **options):
start = time.time()
self.stdout.write('Waiting for database...')
while True:
try:
connection.ensure_connection()
break
except OperationalError:
time.sleep(1)
end = time.time()
self.stdout.write(self.style.SUCCESS(f'Database available! Time taken: {end-start:.4f} second(s)'))
Looks like you want to populate your database with sql file when your db container starts running. Mysql docker hub says
Initializing a fresh instance
When a container is started for the first time, a new database with the specified name will be created and initialized with the provided configuration variables. Furthermore, it will execute files with extensions .sh, .sql and .sql.gz that are found in /docker-entrypoint-initdb.d. Files will be executed in alphabetical order. You can easily populate your mysql services by mounting a SQL dump into that directory and provide custom images with contributed data. SQL files will be imported by default to the database specified by the MYSQL_DATABASE variable.
So your .sql file should be located in /docker-entrypoint-initdb.d in your mysql container. See this post for more.
Last but not least, your db is lost when you run docker-compose down, since you don't have volumes other than sql file. It that's not what you want, you might want to consider the following
version: "3.9"
services:
db:
...
volumes:
- data:/var/lib/mysql
...
volumes:
data:

Related

Configure Docker-compose to connect to my local database [duplicate]

This question already has answers here:
From inside of a Docker container, how do I connect to the localhost of the machine?
(40 answers)
Closed 2 months ago.
I am setting up an application with the Flask framework using MySQL as the database. This database is located locally on the machine. I manage to use the occifielle image of MySQL without problem. Only that I would rather use a local database that is on my computer.
Here is my extract, please help me.
Dockerfile
FROM python:3.9-slim
RUN apt-get -y update
RUN apt install python3-pip -y
WORKDIR /flask_docker_test
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
EXPOSE 80
CMD gunicorn --bind 0.0.0.0:5000 app:app
Docker-compose file
version: "3"
services:
app:
build: .
container_name: app
links:
- db
ports:
- "5000:5000"
depends_on:
- db
networks:
- myapp
db:
image: mysql
command: --default-authentication-plugin=mysql_native_password
restart: always
container_name: mysql_db
environment:
MYSQL_ROOT_PASSWORD: root
MYSQL_DATABASE: flask_test_db
MYSQL_USER: eric
MYSQL_PASSWORD: 1234
ports:
- "3306:3306"
networks:
- myapp
phpmyadmin:
image: phpmyadmin
restart: always
ports:
- 8080:80
depends_on:
- db
environment:
PMA_ARBITRARY: 1
PMA_USER: serge
PMA_HOST: db
PMA_PASSWORD: 1234
networks:
- myapp
networks:
myapp:
I would like to establish a connection with my local database rather than with the database provided by the MySQL container
in order to connect to your local database, you should :
remove the db from your docker-compose.yaml
remove the network myapp
use network_mode host
But IMO you should keep your db in the docker-compose file, otherwise other developers won't be able to start the project on their machine
EDIT : code snippet for network_mode
services:
app:
...
network_mode: host

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

Docker-Compose Output File To Local Host

I have the below docker-compose.yaml file that sets up a database and runs a python script
version: '3.3'
services:
db:
image: mysql:8.0
cap_add:
- SYS_NICE
restart: always
environment:
- MYSQL_DATABASE=test_db
- MYSQL_ROOT_PASSWORD=xxx
ports:
- '3310:3310'
volumes:
- db:/var/lib/mysql
py_service:
container_name: test_py
build: .
command: ./main.py -r compute_init
depends_on:
- db
ports:
- 80:80
environment:
DB_HOST: db
DB_PORT: 3306
DB_USER: root
DB_PASSWORD: xxx
DB_NAME: test_db
links:
- db
volumes:
- py_output:/app/output
volumes:
db:
driver: local
py_output:
To run it I perform the following
docker-compose build
docker-compose up
docker-compose run -v /home/ubuntu/docker_directory/output:/app/output/* py_service
Here is the Dockerfile
FROM python:3.7
RUN mkdir /app
WORKDIR /app
COPY env/requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
CMD ["python3","main.py","-r","compute_init"]
Now this works fine I can see the data has been properly populated under the generated in the msql database.
The python file at the end of the script should dump a csv file to /app/ouput/output.csv (via pandas library df.to_csv("output/output.csv"))
My question is, how to recover that csv from the container to the local directory.
The script seems to finish off without any errors, but can't find the output file at the end.
it seems using docker-compose run -v $(pwd)/output:/app/output py_service
did the job

This site can’t be reached 127.0.0.1 refused to connect flask

I am trying to dockerize a flask project with Redis and SQLite. I kept getting this error when I run the project using docker. The project works just fine when I run it normally using python manage.py run
Dockerfile
FROM python:3.7.2-slim
COPY . /app
WORKDIR /app
RUN pip install --upgrade pip
RUN pip install -r requirements.txt
EXPOSE 5000
CMD ["python","manage.py run", "--host=0.0.0.0"]
docker-compose.yml
version: '3'
services:
sqlite3:
image: nouchka/sqlite3:latest
stdin_open: true
tty: true
volumes:
- ./db/:/root/db/
api:
container_name: flask-container
build: .
entrypoint: python manage.py run
env_file:
- app/main/.env
ports:
- '5000:5000'
volumes:
- ./db/:/root/db/
- ./app/main/:/app/main/
redis:
image: redis
container_name: redis-container
ports:
- "6379:6379"
Please what could be the problem?
Your docker-compose.yml file has several overrides that fundamentally change the way the image works. In particular, the entrypoint: line suppresses the CMD from the Dockerfile, which loses the key --host option. You also should not need volumes: to inject the application code (it's already in the image), nor should you need to manually specify container_name:.
services:
api:
build: .
env_file:
- app/main/.env
ports:
- '5000:5000'
# and no other settings
In the Dockerfile, your CMD has two shell words combined together. You need to split those up into separate words in the JSON-array syntax.
CMD ["python","manage.py", "run", "--host=0.0.0.0"]
# ^^^^ two words
With these two fixes, you'll be running the CMD from the image, with the code built into the image, and with the critical --host=0.0.0.0 option.

docker compose up generate (2005, "Unknown MySQL server host 'db' (-2)") error

Hi all i'm trying to dockerize a django application with a connexion to the database. when i run docker compose up i get this error when the dockerfile is making migrations django.db.utils.OperationalError: (2005, "Unknown MySQL server host 'db' (-2)")
ERROR: Service 'web' failed to build: The command '/bin/sh -c python manage.py makemigrations' returned a non-zero code: 1
here is my Dockerfile
FROM python:3.6
ENV PYTHONUNBUFFERED 1
RUN mkdir /SFP_ingestion
WORKDIR /SFP_ingestion
COPY . /SFP_ingestion
RUN pip install -r requirements.txt
RUN python generatemodel.py
RUN python generateapp.py
RUN python manage.py makemigrations
RUN python manage.py migrate
RUN python manage.py migrate easyaudit
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
and here is my docker-compose.yml
services:
db:
image: mysql
restart: always
command: --default-authentication-plugin=mysql_native_password --mysqlx=0
environment:
- MYSQL_HOST=localhost
- MYSQL_PORT=3306 # cannot change this port to other number
- MYSQL_DATABASE=sfp # name you want for the database
- MYSQL_USER=root # change to whatever username you want
- MYSQL_PASSWORD=password #change to the password you want for user
- MYSQL_ROOT_PASSWORD=password #change to good root password
ports:
- "3306:3306"
expose:
- "3306"
volumes:
- "./db:/var/lib/mysql"
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/SFP_ingestion
restart: always
ports:
- "8000:8000"
depends_on:
- db
You have to specify network for your containers.
https://docs.docker.com/compose/networking/

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