I am dockerizing a React-Flask web application with separate containers for the frontend and the backend Flask API. Up to now I have only run this on my localhost using the default Flask development server. I then installed Gunicorn to prep the application for deployment with Docker later, and that also ran smoothly on my localhost.
After I ran docker compose up the two images built successfully, are attached to the same network, and I got this in the logs:
Logs For backend:
Starting gunicorn 20.1.0
Listening at: http://0.0.0.0:5000 (1)
Using worker: gthread
Logs For frontend:
react-flask-app#0.1.0 start
react-scripts start
Project is running at http://172.21.0.2/
Starting the development server...
But when I try to access the site at http://172.21.0.2/, localhost:5000 or localhost:3000 it is not accessible. Do I maybe need to add the name of the frontend or backend service?
In Docker Desktop it's showing that the frontend is running at port 5000 but there is no port listed for the backend, it just says it's running.
This is what my files and setup look like:
I added a gunicorn_config.py file as I read it is a good practice, rather than adding all of the arguments to the CMD in the Dockerfile:
bind = "0.0.0.0:5000"
workers = 4
threads = 4
timeout = 120
Then in my Flask backend Dockerfile I have the following CMD for Gunicorn:
FROM python:3.8-alpine
EXPOSE 5000
WORKDIR /app
COPY requirements.txt requirements.txt
ADD requirements.txt /app
RUN pip install --upgrade pip
ADD . /app
COPY . .
RUN apk add build-base
RUN apk add libffi-dev
RUN pip install -r requirements.txt
CMD ["gunicorn", "--config", "gunicorn_config.py", "main:app"]
Here I do "main:app" where my Flask app file is called main.pyand then app is my Flask app object.
I'm generally confused about ports and how this will interact with Gunicorn and in general. I specified port 5000 in the EXPOSE of both of my Dockerfiles.
This is my frontend Dockerfile:
WORKDIR /app
COPY . /app
RUN npm install --legacy-peer-deps
COPY package*.json ./
EXPOSE 3000
ENTRYPOINT [ "npm" ]
CMD ["start"]
And used 5000 in the bind value of my Gunicorn config file. Also, I previously added port 5000 as a proxy in package.json.
I will initially want to run the application using Docker on my localhost but will deploy it to a public host service like Digital Ocean later.
This is my Docker compose file:
services:
middleware:
build: .
ports:
- "5000:5000"
frontend:
build:
context: ./react-flask-app
dockerfile: Dockerfile
ports:
- "3000:3000"
The other thing to mention is that I also created a wsgi.py file and I was wondering do I need to add this to the Gunicorn CMD in my Dockerfile:
from main import app
if __name__ == "__main__":
app.run()
Related
I am running FastApi via docker by creating a sevice called ingestion-data in docker-compose. My Dockerfile :
FROM tiangolo/uvicorn-gunicorn-fastapi:python3.7
# Environment variable for directory containing our app
ENV APP /var/www/app
ENV PYTHONUNBUFFERED 1
# Define working directory
RUN mkdir -p $APP
WORKDIR $APP
COPY . $APP
# Install missing dependencies
RUN pip install -r requirements.txt
AND my docker-compose.yml file
version: '3.8'
services:
ingestion-service:
build:
context: ./app
dockerfile: Dockerfile
ports:
- "80:80"
volumes:
- .:/app
restart: always
I am not sure why this is not picking up any change automatically when I make any change in any endpoint of my application. I have to rebuild my images and container every time.
Quick answer: Yes :)
In the Dockerfile, you copying your app into /var/www/app.
The instructions form the Dockerfile are executed when you build your image (docker build -t <imgName>:<tag>)
If you change the code later on, how could the image be aware of that?
However, you can mount a volume(a directory) from your host machine, into the container when you execute the docker run / docker-compose up command, right under /var/www/app. You'll then be able to change the code in your local directory and the changes will automatically be seen in the container as well.
Perhaps you want to mount the current working directory(the one containing your app) at /var/www/app?
volumes:
- .:/var/www/app
I'm running Linux Mint with Python 3.6.
I have read through every link on here but can't figure out what is wrong. I am running a simple flask app which works fine when I'm running it locally on my machine, but then running it with Docker I can't access the IP in my browser.
I have set the flask app to run on host 0.0.0.0, with app.run(host='0.0.0.0').
Dockerfile:
FROM python:3.7
RUN mkdir -p /var/app
WORKDIR /var/app
COPY . /var/app
RUN pip install --upgrade pip
RUN pip install -r requirements.txt
EXPOSE 5000
CMD ["pytest", "-v", "tests/test_flask_api.py"]
# CMD ["python3", "app.py"]
CMD ["python3", "-m", "Flask", "run", "--host=0.0.0.0"]
docker-compose.yml:
web:
build: ./app
ports:
- "5000:5000"
volumes:
- .:/code
After running the command docker-compose up -d to build and run the container, I run the command docker inspect --format '{{ .NetworkSettings.IPAddress }}' to get the IP address of the container as 172.17.0.2.
I try to access the site via 172.17.0.2:5000 and localhost:5000, but both just hang and don't load.
Finally, I ran docker exec -it restapimma_web_1 /bin/bash to get into the container. Then I ran curl localhost:5000 and was able to get the correct response. So the flask app is running inside the container I just can't access it outside the container.
I had a similar problem. To get it working:
Allow your flask app to accept a HOST argument from your environment
if __name__ == "__main__":
app.run(
host=os.environ.get("BACKEND_HOST", "172.0.0.1"),
port=your_port,
debug=True,
)
set your host environmental var in your composition
services:
[your service name]:
image:[your image]
environment:
- BACKEND_HOST=[your service name]
ports:
- "[etc]"
Basically flask wants to be called using the right hostname
I have react app which communicates with flask API and display data. I had both of these projects in separate folders and everything worked fine.
Then I wanted to containerize Flask + React app with docker-compose for practice and then I created a folder in which I have my middleware(flask) and frontend(react) folders. Then I created a virtual environment and installed flask. Now when I import flask inside python file I get an error.
I do not understand why simply adding the folder inside another folder would affect my project. You can see the project structure and error in the picture below.
Dockerfile react app
FROM node:latest
# Create app directory
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY package.json /usr/src/app/
RUN npm install
CMD [ "npm", "start" ]
Dockerfile flask api
FROM python:3.7.2
# set working directory
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
# add requirements (to leverage Docker cache)
ADD ./requirements.txt /usr/src/app/requirements.txt
# install requirements
RUN pip install -r requirements.txt
# add app
ADD . /usr/src/app
# run server
CMD python app.py runserver -h 0.0.0.0
docker-compose.yml
version: '3'
services:
middleware:
build: ./middleware
expose:
- 5000
ports:
- 5000:5000
volumes:
- ./middleware:/usr/src/app
environment:
- FLASK_ENV=development
- FLASK_APP=app.py
- FLASK_DEBUG=1
frontend:
build: ./frontend
expose:
- 3000
ports:
- 3000:3000
volumes:
- ./frontend/src:/usr/src/app/src
- ./frontend/public:/usr/src/app/public
links:
- "middleware:middleware"
When moving folders around, you should change the python path in your vscode/.settings file. Otherwise you'll be using the wrong Python interpreter - one without Flask.
Django server is running well in localhost. however, When I try to run server on the docker container, it doesn't find the manage.py file when using docker-compose file and even I run the container manually and run the server, it doesn't appear in browser. how can I solve this problem?
So I wrote all the code testing on my local server and using the dockerfile, I built the image of my project.
and I tried to run server on the docker container, suddenly this doesn't run.
what's worse, if I use docker-compose to run the server, it doesn't find the manage.py file though I already checked with 'docker run -it $image_name sh'
here is the code of my project
I am new to docker and new to programming.
hope you can give me a help. thanks!
file structure
current directory
└─example
└─db.sqlite3
└─docker-compose.yml
└─Dockerfile
└─manage.py
└─Pipfile
└─Pipfile.lock
Docker file
# Base image - Python version
FROM python:3.6-alpine
# Set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
# Set work directory
WORKDIR /code
# Copy Pipfile
COPY Pipfile /code
COPY Pipfile.lock /code
# Install dependencies
RUN pip install pipenv
RUN pipenv install --system
# Copy files
COPY . /code/
docker-compose.yml
# docker-compose.yml
version: '3.3'
services:
web:
build: .
command: python /code/manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- 8000:8000
expected result : running server in web browser like in chrome
actual result :
when using docker-compose :
ERROR like this in the prompt : web_1 | python: can't open file '/code/manage.py': [Errno 2] No such file or directory
when running the container manually with 'docker run -it $image_name sh' and 'python manage.py runserver' on the shell :
server is running but, doesn't connect to web browser. (doesn't show up in browser like chrome'
Yo have done same thing in many ways. You have copy source files using a COPY command and then you have mounted a host volume in your docker-compose.yml file. In first place you don't need a volume because volume mounts are to persisting data generated by and used by Docker containers.
Following simplified Dockerfile and docker-compose file would fix the problem.
# Base image - Python version
FROM python:3.6-alpine
# Set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
# Copy files
COPY . /code/
# Set work directory
WORKDIR /code
# Install dependencies
RUN pip install pipenv
RUN pipenv install --system
docker-compose.yml -:
# docker-compose.yml
version: '3.3'
services:
web:
build: .
command: python ./manage.py runserver 0.0.0.0:8000
ports:
- 8000:8000
I have looked through the questions on this site, but I have not been able to fix this problem.
I created and ran an image of my django app, but when I try to view the app from the browser, the page does not load (can't establish a connection to the server)
I am using docker toolbox, I am using OS X El Capitan and the Macbook is from 2009.
The container IP is: 192.168.99.100
The django project root is called "Web app" and is the directory containing manage.py. My Dockerfile and my requirements.txt files are in this directory.
My dockerfile is:
FROM python:3.5
WORKDIR /usr/src/app
COPY requirements.txt ./
RUN pip install -r requirements.txt
COPY . .
EXPOSE 8000
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
My requirements.txt has django and mysqlclient
My django app uses Mysql, and I tried to view the dockerized django app in the browser with and without linking it to the standard mysql image. In both cases, I only see the following error:
problem loading page couldn't establish connection to server
When I did try linking the django container to the mysql container I used:
docker run --link mysqlapp:mysql -d app
Where mysqlapp is my mysql image and 'app' is my django image.
In my django settings.py, the allowed hosts are:
ALLOWED_HOSTS: ['localhost', '127.0.0.1', '0.0.0.0', '192.168.99.100']
Again, the image is successfully created when I used docker build, and it is successfully run as a container. Why is the page not loading in the browser?
I suggest to use yml file and docker compose. Below is a template to get you started:
[Dockerfile]
FROM python:2.7
RUN pip install Django
RUN mkdir /code
WORKDIR /code
COPY code/ /code/
where your files are located in code directory.
[docker-compose.yml]
version: '2'
services:
db:
image: mysql
web0:
build: .
command: python manage.py runserver 0.0.0.0:8000
ports:
- "8000:8000"
depends_on:
- db
There might be a problem with your working directory path defined in Dockerfile. Hope above helps.
Solution provided by salehinejad seems to be good enough ,although i have not tested it personally but if you do not want to use yml file and want to go your way then you should expose the port by adding
-p 0:8000
in your run command
So your should look like this :
docker run -p 0:8000 --link mysqlapp:mysql -d app
I suspect you have not told Docker to talk to your VM, and that your containers are running on your host machine (if you can access at localhost, this is the issue).
Please see this post for resolution:
Connect to docker container using IP