Docker

Docker

What this is

Docker is a containerization platform that allows developers to package, ship, and run applications in containers. Containers are lightweight and portable, enabling consistent and reliable deployments across different environments. Docker provides a simple and efficient way to manage applications and their dependencies.

Installation

curl -fsSL https://get.docker.com -o get-docker.sh
sh get-docker.sh

Key concepts

The most important APIs and patterns in Docker include:

• Images: Templates for creating containers. Example: docker pull ubuntu to pull the Ubuntu image.
• Containers: Isolated environments for running applications. Example: docker run -it ubuntu to run a new container from the Ubuntu image.
• Volumes: Shared file systems between containers and the host machine. Example: docker run -v /host/path:/container/path ubuntu to mount a volume.
• Networking: Communication between containers. Example: docker network create my-network to create a new network.

Correct usage patterns

Real code examples from the Docker documentation include:

• Running a new container: docker run -it ubuntu /bin/bash
• Building a Docker image: docker build -t my-image .
• Pushing an image to Docker Hub: docker tag my-image:latest <username>/my-image:latest and docker push <username>/my-image:latest

Common mistakes to avoid

Common mistakes when using Docker include:

• Not specifying the correct port mappings when running a container.
• Not using volumes to persist data between container restarts.
• Not optimizing Docker images for size and performance.

File and folder conventions

Docker files and folders typically follow these conventions:

• Dockerfile: The build file for a Docker image, usually located in the root of the project directory.
• docker-compose.yml: The configuration file for defining and running multi-container applications, usually located in the root of the project directory.
• .dockerignore: The file specifying files and directories to ignore during the build process, usually located in the root of the project directory.