Book Image

Docker Certified Associate (DCA): Exam Guide

By : Francisco Javier Ramírez Urea
Book Image

Docker Certified Associate (DCA): Exam Guide

By: Francisco Javier Ramírez Urea

Overview of this book

Developers have changed their deployment artifacts from application binaries to container images, and they now need to build container-based applications as containers are part of their new development workflow. This Docker book is designed to help you learn about the management and administrative tasks of the Containers as a Service (CaaS) platform. The book starts by getting you up and running with the key concepts of containers and microservices. You'll then cover different orchestration strategies and environments, along with exploring the Docker Enterprise platform. As you advance, the book will show you how to deploy secure, production-ready, container-based applications in Docker Enterprise environments. Later, you'll delve into each Docker Enterprise component and learn all about CaaS management. Throughout the book, you'll encounter important exam-specific topics, along with sample questions and detailed answers that will help you prepare effectively for the exam. By the end of this Docker containers book, you'll have learned how to efficiently deploy and manage container-based environments in production, and you will have the skills and knowledge you need to pass the DCA exam.
Table of Contents (22 chapters)
1
Section 1 - Key Container Concepts
8
Section 2 - Container Orchestration
12
Section 3 - Docker Enterprise
17
Section 4 - Preparing for the Docker Certified Associate Exam

Understanding DTR components and features

DTR is the Docker Enterprise's platform registry, used to store and manage images. It is deployed on top of defined UCP worker nodes. DTR will run as a multi-container application. This means that all containers will run together, associated with just one defined node. In the case of node failure, no other nodes will take its DTR containers. This is very important because we need to deploy multiple DTR deployments, on different nodes.

DTR uses RethinkDB as a database to store and sync data between registry nodes. To provide high availability to DTR, we need to deploy an odd number of replicas. We will use three replicas, so we need to deploy DTR workloads on three worker nodes. Synchronization will be done using overlay networking. DTR installation will create a dtr-ol overlay network and this will be used internally for replica synchronization.

Each replica will deploy the following processes:

Replica (DTR instance)

Process

dtr...