Track 3: Managing Multiple Containers

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Step-by-Step Guide

1. Open Terminal:

   • Launch PowerShell if not default

2. Create a New Project Directory:

• Navigate to the location where you want to create your project directory.

  • Create a new directory for your project:

mkdir fastapi-docker
cd fastapi-docker
code .

• This will open a new VScode window

• Open the terminal in VSCode (Ctrl + `).

1. Create the src Directory:

   • Inside your project directory, create a src directory:

mkdir src

1. Create main.py Inside src:

   • Navigate into the src directory and create the main.py file:

2. Add Code to main.py:

   • Open main.py in VSCode and add the following code:

import redis
from fastapi import FastAPI

app = FastAPI()

# Connect to Redis
redis_client = redis.Redis(host='redis', port=6379, db=0)

@app.get("/")
def read_root():
    redis_client.incr('hits')
    hits = redis_client.get('hits').decode('utf-8')
    return {"message": "Hello World", "hits": hits}

@app.get("/items/{item_id}")
def read_item(item_id: int, q: str = None):
    redis_client.set(f'item:{item_id}', q)
    stored_value = redis_client.get(f'item:{item_id}').decode('utf-8')
    return {"item_id": item_id, "stored_value": stored_value}

1. Create requirements.txt:

   • Go back to the root of your project directory and create a requirements.txt file:

cd ..
touch requirements.txt

• Add the following dependencies to requirements.txt:

fastapi
uvicorn
redis

1. Create the Dockerfile:

   • In the root of your project directory, create a Dockerfile: Dockerfile

   • Add the following content to the Dockerfile:

#Get the latest image Pythton:3.14-slim
FROM python:3.13-slim

WORKDIR /code

#Copy requirements file
COPY ./requirements.txt ./

RUN pip install --no-cache-dir -r requirements.txt

COPY ./src ./src

CMD ["uvicorn", "src.main:app", "--host", "0.0.0.0", "--port", "80", "--reload"]

Automate Docker creation using YML

Create docker-compose.yml file in parent directory

services:
  app:
    build: .
    container_name: python-cont
    command: uvicorn src.main:app --host 0.0.0.0 --port 80 --reload
    ports:
      - 80:80
    volumes:
      - .:/code

  redis:
    image: "redis:latest"
    container_name: redis-cont
    ports:
    - "6379:6379"

Run docker compose

 docker compose up --build -d

Access the Application

Open your web browser and go to http://localhost:80. Any changes you make to main.py in the src directory will be automatically reflected in the running container.