Containerize Python Application(Flask) using Docker

Photo by Luca Bravo on Unsplash

Prerequisites:

• You must have docker installed on your machine (https://docs.docker.com/engine/install/)
• Docker must be up and running
• You must have docker-compose installed on your machine (https://docs.docker.com/compose/install/)

Photo by Hal Gatewood on Unsplash

Step-1

• we have a Flask app(app.py) that runs on port 5000

• Now we are going to create requirements.txt. The place where we are going to note all our python modules to install in the container.

Note: You can also generate requiremens.txt using the below command-

pip freeze > requirements.txt

Step-2

• Let's create a Dockerfile that contains only 4 lines of code

Line 1:- “FROM python”

• this line commands to pull the latest python image. https://hub.docker.com/_/python

Line 2:- “WORKDIR /app”

• Declaring working directory

Line 3:- “COPY . .”

• By this, all the data present in the current directory will be copied to WORDIR.

Line 4:- “RUN pip install -r requirements.txt”

• Installing all our modules that are present in the requirements.txt.

Warning:-

For external Visibility, we have to make sure “host=’0.0.0.0'”

app.run(host=’0.0.0.0', port=5000)

Now you can build — “docker build -t dockerName .”

Run — “docker run -p 5000:5000 dockerName”

Step-3(Optional)

• Create docker-compose.yml

Run — “docker-compose up ”

Now the flask is running at “http://localhost:5000/”.