Learning Docker - Second Edition: What You Need to Know About Docker and Kubernetes
Learning Docker - Second Edition book pdf
If you are looking for a comprehensive and practical guide to learn how to use Docker for developing and deploying applications, then you might want to check out the book Learning Docker - Second Edition by Jeeva S. Chelladhurai, Vinod Singh, and Pethuru Raj. This book is available in pdf format and you can download it from Packt Publishing.
Learning Docker - Second Edition book pdf
In this article, we will give you a brief overview of what this book covers and why you should read it. We will also show you how to get started with Docker and how to use some of its basic commands and tools. Finally, we will give you some resources and references to learn more about Docker.
What is Docker and why should you learn it?
Docker is a software platform that allows you to build, run, and share applications using containers. Containers are lightweight and isolated environments that package the code, dependencies, configuration, and runtime of an application. Containers can run on any machine that has Docker installed, regardless of the operating system or hardware.
Docker has many benefits for developers and operators, such as:
It simplifies the development process by providing a consistent environment across different machines.
It enables faster delivery by allowing you to create and deploy applications with minimal overhead.
It improves the scalability and reliability of applications by enabling you to run multiple containers on a single host or across a cluster of hosts.
It enhances the portability and compatibility of applications by allowing you to run them on any platform that supports Docker.
It fosters collaboration and innovation by allowing you to share your containers with others through registries like Docker Hub.
Docker has many use cases for different scenarios, such as:
It can be used for local development by allowing you to create a sandbox environment that mimics the production environment.
It can be used for testing and debugging by allowing you to isolate and reproduce issues in a controlled environment.
It can be used for continuous integration and delivery by allowing you to automate the build, test, and deployment processes using tools like Jenkins and Docker Desktop.
It can be used for microservices architecture by allowing you to break down your application into smaller and independent services that communicate with each other through APIs.
It can be used for cloud computing by allowing you to run your applications on any cloud provider that supports Docker, such as Amazon Web Services, Microsoft Azure, and Google Cloud Platform.
How to get started with Docker
To get started with Docker, you need to install and run it on your machine. Depending on your operating system, you can choose between two options: Docker Desktop or Docker Engine.
Docker Desktop is a graphical user interface (GUI) application that includes Docker Engine, Docker Compose, and other tools. It is available for Windows and Mac OS X.
Docker Engine is a command-line interface (CLI) application that allows you to create and manage Docker images and containers. It is available for Linux, Windows, and Mac OS X.
Installing Docker on Windows
To install Docker Desktop on Windows 10, you need to have a 64-bit version of Windows 10 Pro, Enterprise, or Education with Hyper-V and Containers features enabled. You can follow these steps to install Docker Desktop on Windows 10:
Download the latest version of Docker Desktop from here.
Run the installer and follow the instructions on the screen.
After the installation is complete, restart your computer.
Launch Docker Desktop from the Start menu or the desktop icon.
Sign in with your Docker ID or create one if you don't have one.
You can now use Docker Desktop to create and manage your containers.
Installing Docker on Linux
To install Docker Engine on Linux, you need to have a 64-bit version of a supported Linux distribution, such as Ubuntu, Debian, CentOS, or Fedora. You can follow these steps to install Docker Engine on Ubuntu 20.04 LTS:
Update the apt package index and install the required packages:
sudo apt-get update sudo apt-get install \ apt-transport-https \ ca-certificates \ curl \ gnupg \ lsb-release
Add Docker's official GPG key:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
Add the stable repository:
echo \ "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \ $(lsb_release -cs) stable" sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
Update the apt package index and install Docker Engine:
sudo apt-get update sudo apt-get install docker-ce docker-ce-cli containerd.io
Add your user to the docker group to run Docker commands without sudo:
sudo usermod -aG docker $USER
Log out and log back in for the changes to take effect.
You can now use Docker Engine to create and manage your containers.
Installing Docker on Mac
To install Docker Desktop on Mac OS X, you need to have a Mac with Intel processor or Apple silicon chip running Mac OS X 10.14 or newer. You can follow these steps to install Docker Desktop on Mac OS X:
Download the latest version of Docker Desktop from here.
Double-click the downloaded file and drag the Docker icon to the Applications folder.
Launch Docker Desktop from the Applications folder or the Launchpad.
If prompted, authorize the installation with your system password.
access to Docker Desktop.
Sign in with your Docker ID or create one if you don't have one.
You can now use Docker Desktop to create and manage your containers.
How to use Docker commands and tools
Once you have installed and run Docker on your machine, you can use the Docker CLI to interact with Docker. The Docker CLI allows you to perform various tasks, such as creating and managing images and containers, using different commands and options. You can also use other tools that are included with Docker, such as Docker Compose, to simplify and automate some of these tasks.
How to create and manage Docker images
A Docker image is a read-only template that contains the code, dependencies, configuration, and runtime of an application. You can create a Docker image from a Dockerfile, which is a text file that specifies the instructions to build the image. You can also pull a Docker image from a registry, such as Docker Hub, which is a repository of pre-built images. You can also push your own images to a registry to share them with others. You can also tag your images with names and versions to identify them easily. You can also remove your images when you don't need them anymore.
Here are some of the basic commands to create and manage Docker images:
To build an image from a Dockerfile in the current directory, use the docker build command:
docker build -t myapp:1.0 .
To pull an image from a registry, use the docker pull command:
docker pull ubuntu:20.04
To push an image to a registry, use the docker push command:
docker push myapp:1.0
To tag an image with a new name or version, use the docker tag command:
docker tag myapp:1.0 myapp:latest
To list all the images on your machine, use the docker images command:
docker images
To remove an image from your machine, use the docker rmi command:
docker rmi myapp:1.0
How to create and manage Docker containers
A Docker container is a running instance of a Docker image. You can create and run a container from an image using the docker run command. You can also stop, start, restart, pause, resume, attach, exec, and remove containers using different commands. You can also inspect the details of a container using the docker inspect command.
Here are some of the basic commands to create and manage Docker containers:
To create and run a container from an image in the background, use the docker run command with the -d option:
docker run -d --name mycontainer myapp:1.0
To stop a running container, use the docker stop command:
docker stop mycontainer
To start a stopped container, use the docker start command:
docker start mycontainer
To restart a container, use the docker restart command:
docker restart mycontainer
To pause a running container, use the docker pause command:
docker pause mycontainer
To resume a paused container, use the docker unpause command:
docker unpause mycontainer
To attach to a running container's standard input/output/error streams, use the docker attach command:
docker attach mycontainer
To execute a command in a running container, use the docker exec command:
docker exec mycontainer ls -l
To list all the containers on your machine, use the docker ps command:
docker ps -a
To remove a container from your machine, use the docker rm command:
docker rm mycontainer
To inspect the details of a container, use the docker inspect command:
docker inspect mycontainer
How to use Docker Compose
Docker Compose is a tool that allows you to define and run multi-container applications with Docker. You can use a YAML file called docker-compose.yml to specify the services, networks, volumes, and dependencies of your application. You can then use the docker-compose command to create and start your containers with a single command.
Here is an example of a docker-compose.yml file that defines a simple web application with two services: web and db.
version: "3.9" services: web: image: myapp:1.0 ports: - "80:80" depends_on: - db db: image: mysql:5.7 environment: MYSQL_ROOT_PASSWORD: secret MYSQL_DATABASE: mydb
To create and start the containers defined in the docker-compose.yml file, use the docker-compose up command:
docker-compose up -d
To stop and remove the containers, use the docker-compose down command:
docker-compose down
How to use Docker for development and deployment
Docker can be used for different stages of the software development lifecycle, such as local development, testing and debugging, and continuous integration and delivery. In this section, we will give you some examples of how to use Docker for these purposes.
How to use Docker for local development
Docker can help you create a sandbox environment that mimics the production environment on your local machine. This way, you can develop your application without worrying about the dependencies, configuration, and runtime issues. You can also use Docker to run multiple services and applications on your machine without conflicts or interference.
To use Docker for local development, you need to have a Dockerfile that defines how to build your application image and a docker-compose.yml file that defines how to run your application containers. You can then use the docker build and docker-compose up commands to create and start your containers. You can also use the docker logs, docker exec, and docker inspect commands to monitor and interact with your containers.
Here are some of the best practices and tips to use Docker for local development:
Avoid using the :latest tag for your images and base images. Instead, use specific versions or hashes to ensure reproducibility and avoid breaking changes.
Avoid using large or unnecessary files in your images. Instead, use multi-stage builds, .dockerignore files, and COPY/ADD instructions to reduce the size and complexity of your images.
Avoid using privileged or root users in your containers. Instead, use non-root users with minimal permissions to improve security and avoid permission issues.
Avoid hard-coding configuration values in your images or containers. Instead, use environment variables, secrets, or config files to inject configuration values at runtime.
Avoid exposing unnecessary ports or services in your containers. Instead, use networks, links, or service discovery to communicate between your containers.
Avoid running multiple processes in a single container. Instead, use one process per container to follow the single responsibility principle and improve scalability and reliability.
Avoid manually creating or managing your containers. Instead, use tools like Docker Compose, Docker Swarm, or Kubernetes to automate and orchestrate your containers.
Avoid using different environments or platforms for development and production. Instead, use the same Docker images and configurations for both stages to ensure consistency and compatibility.
How to use Docker for testing and debugging
you test and debug your application in a controlled and isolated environment. You can use Docker to create and run test cases, simulate different scenarios, and reproduce and fix issues. You can also use Docker to integrate with other tools and frameworks that can help you with testing and debugging.
To use Docker for testing and debugging, you need to have a Dockerfile that defines how to build your application image and a docker-compose.yml file that defines how to run your application containers. You can then use the docker build and docker-compose up commands to create and start your containers. You can also use the docker logs, docker exec, docker inspect, and docker cp commands to monitor and interact with your containers.
Here are some of the techniques and tools that you can use with Docker for testing and debugging:
You can use unit testing frameworks, such as Jest, Mocha, or pytest, to test the functionality and logic of your code. You can run these frameworks inside your containers or outside your containers using volumes or bind mounts.
You can use integration testing frameworks, such as Selenium, Cypress, or Robot Framework, to test the interaction and integration of your components and services. You can run these frameworks inside your containers or outside your containers using networks or links.
You can use performance testing tools, such as JMeter, Locust, or k6, to test the scalability and reliability of your application. You can run these tools inside your containers or outside your containers using ports or services.
You can use code analysis tools, such as SonarQube, ESLint, or Flake8, to check the quality and style of your code. You can run these tools inside your containers or outside your containers using volumes or bind mounts.
You can use debugging tools, such as Visual Studio Code Remote - Containers, PyCharm Docker Remote Interpreter, or Node.js Debugger in Docker, to debug your code in real time. You can run these tools inside your containers or outside your containers using volumes or bind mounts.
You can use logging and monitoring tools, such as ELK Stack, Prometheus, or Grafana, to collect and visualize the logs and metrics of your application. You can run these tools inside your containers or outside your containers using networks or links.
You can use error tracking tools, such as Sentry, Rollbar, or Airbrake, to capture and report the errors and exceptions of your application. You can run these tools inside your containers or outside your containers using networks or links.
You can use security scanning tools, such as Docker Scan, Trivy, or Anchore Engine, to scan and identify the vulnerabilities and risks of your images and containers. You can run these tools inside your containers or outside your containers using volumes or bind mounts.
How to use Docker for continuous integration and delivery
Docker can help you automate the build, test, and deployment processes of your application using continuous integration and delivery (CI/CD) pipelines. You can use Docker to create and run your application containers in different environments, such as development, staging, and production. You can also use Docker to integrate with other tools and platforms that can help you with CI/CD, such as Jenkins, GitHub Actions, or AWS CodeDeploy.
To use Docker for CI/CD, you need to have a Dockerfile that defines how to build your application image and a docker-compose.yml file that defines how to run your application containers. You also need to have a CI/CD tool or platform that can trigger and execute your pipeline steps based on events, such as code commits, pull requests, or merges. You also need to have a registry that can store and distribute your images, such as Dock