Intro to Containers

• Reading material

Prerequisites

• Ensure you have Python and Docker Desktop (or Rancher Desktop) installed on your machine.
• Create a virtual environment for your Python project and install the required packages like Flask.

Setting Up the Application

1. Create and activate a virtual environment:

   python3 -m venv venv
   source venv/bin/activate  # On Windows use `venv\Scripts\activate`

2. Install Flask:

   pip install flask

3. Create app.py:

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def hello_world():
       return 'We are running our first container - from CoderCo'
   
   if __name__ == '__main__':
       app.run(host='0.0.0.0', port=5000)

4. Create requirements.txt:

   flask

Running the Application Directly

1. Run the Flask app:

   python3 app.py

2. Access the app:

   • Open http://localhost:5000 in your browser
   • Or run curl http://localhost:5000 in your terminal

Running the Application in a Docker Container

1. Create a Dockerfile:

   # this is your base image
   FROM python:3.9
   
   # we set the working dir in yourr container
   WORKDIR /usr/src/app
   
   # copying reqs file to your container so you can install the app reqs ygm
   COPY requirements.txt ./
   RUN pip install --no-cache-dir -r requirements.txt
   
   # copy your app code fam
   COPY . .
   
   # expose/open up the port on your container so you can access your app ygm
   EXPOSE 5000
   
   # running app in container
   CMD ["python", "app.py"]

2. Build the Docker image:

   docker build -t coderco .

3. Run the Docker container:

   docker run -p 5001:5001 coderco

4. Access the app:

   • Open http://localhost:5000 in your browser
   • Or run curl http://localhost:5000 in your terminal

Challenge

• Access our challenge here