Python Web Framework Flask App on Docker Container

 Namaste this post is an extension of the Docker image management. In this post, I would like to talk about how the Dockerfile content will work to build the Python web framework using the Flask app.

Let's consider a web platform we have multiple choices to use as a web application to run on docker container:

1. Python web app using Flask
2. Node.JS app
3. Web app run with Go

For all these program execution structures is similar you must have 'app' folder. Where you can write your web application code.

FROM python:3.9.4-alpine

COPY requirements.txt /
RUN pip3 install -r /requirements.txt

COPY . /app
WORKDIR /app

ENTRYPOINT ["./gunicorn.sh"]

Here the base image used as Python3 version with apline which is thinner image. As pip installer will use requirement.txt file to install the dependencies libraries and packages required for running Flask.
COPY instruciton used to copy the files from docker host machine to container image.
WORKDIR is like cd command.
ENTRYPOINT instruction will take param which can be a script or command that could be executed

Step 1: Get the Flask Docker app Dockerflle from GitHub. You can have the following repository by Fort on the GitHub then you can use the

git clone

on Docker daemon running VM.

    git clone https://github.com/BhavaniShekhar/Flask_Docker_App-1.git
    cd Flask_Docker_App-1/
	ls -lrt
  

Step 2: Update some files and commit your changes. Here I've modified the index.html present in the

 vi app/templates/index.html

. Now, all set we can save the changes.

  git add .
  git commit -m 'added text to index.html'
  

Remember this will works only when you set the

 git config --global user.email 

and

 git config --global user.name

Step 3: Build the docker image with the following command:

 
  docker build -t flask:1.3 .
  

Step 4: Construct the container based on the flask image

 
  docker run -d -p 8081:80 flask:1.3
  

Step 5: Python Flask based web app ready to use open a browser and try to access it with host ip and host port http://192.168.33.250:8081/

You can see the output as follows: