preface

What is a Docker?

Docker is an open source software project, so that the deployment of applications under the software container can be automated, so as to provide an additional software abstraction layer on the Linux operating system, as well as the automatic management mechanism of operating system layer virtualization. Docker makes use of the resource separation mechanism in Linux core, such as Cgroups, and Linux core namespace (name space) to set up independent software containers. This can operate under a single Linux entity, avoiding the additional burden of starting a virtual machine.

Container technology is extremely hot in recent years, and Docker, as a representative of container technology, is also very hot, almost an Internet celebrity in the software industry. Such a popular Docker has long been applied in the production environment, and the most representative large manufacturers in the domestic container circle are Ali and JINGdong.

Jingdong started container deployment in production environment in 2014. In June 2015, jingdong ran 150,000 docker instances, and has realized 100% application container deployment so far. According to CNCF (Cloud Native Computing Foundation) data statistics, The world’s largest Docker cluster is deployed on JD! Talk to JD.com: Kubernetes, Cloud Native and CNCF projects push big data and AI

Haifeng Liu, CHIEF architect of JD: JD is one of the early adopters of Kubernetes. The company currently manages the largest Kubernetes cluster in the world, with more than 20,000 bare metal services distributed across data centers in multiple regions.

Since Docker is so popular, let’s take a look at docker in action

Docker In action is designed to introduce the Docker project and Linux container concepts to developers, system administrators, and other computer users with mixed skills. Both Docker and Linux are open source projects with abundant online documentation, but getting started is still a daunting task.

Docker is one of the fastest growing open source projects of all time, and the ecosystem around it is growing at a similar rate. For these reasons, the focus of the book is entirely on Docker’s toolset. This scope limitation not only makes content selection more accurate, but also helps readers understand how to apply Docker features in their specific instances. Once readers have a firm grasp of the basics of the book, they can also tackle the bigger questions and explore the entire ecosystem.

summarize

Part 1 covers the features of Docker and containers. Helps you understand how to install and uninstall software released in Docker. You’ll learn how to run, manage, and connect different types of software in different container structures. The first part introduces the basic skills needed by every Docker user.

Part 2 introduces Docker packaging and software distribution, covering the underlying mechanism of Docker images of different sizes, as well as the investigation of different packaging and distribution methods. The second part also includes an in-depth analysis of the Docker Distribution project.

Part 3 covers multi-container projects and multi-host environments, covering Docker Compose, Machine, and Swarm projects. Part 3 will guide you through building and deploying multiple real-world instances that approximate the scale of large-scale server software.