Docker

What is Docker?

Docker is an open source platform that enables automating the deployment of applications within software containers, providing an additional layer of abstraction and automation.

Key Concepts

Containers

A container is a standard unit of software that packages code and all its dependencies.

Images

A Docker image is a read-only template with instructions for creating a container.

Dockerfile

Text file that contains all the commands needed to build an image.

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FROM ubuntu:22.04

RUN apt-get update && apt-get install -y \
    python3 \
    python3-pip

WORKDIR /app

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

COPY . .

CMD ["python3", "app.py"]

Basic Commands

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# Build image
docker build -t my-app:latest .

# Run container
docker run -d -p 8080:80 my-app:latest

# List containers
docker ps

# View logs
docker logs <container-id>

# Stop container
docker stop <container-id>

Advantages

✅ Portability: Works the same in any environment
✅ Efficiency: Fewer resources than virtual machines
✅ Isolation: Each container is independent
✅ Scalability: Easy to scale horizontally

References