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

Multistage building and image caches

Multistage building is a feature that appeared with Docker 17.05. Prior to this version, if we wanted to ensure minimum image size and void compilers on final production images, we usually had to install the packages required for compiling, execute the binary's build, and then remove all non-required software, including used compilers, which are a real security problem in production.

Automating this kind of compilation was not easy, and sometimes, we needed to create our own scripts to reproduce those steps on every build, usually using third-party CI/CD orchestrations.

We can use many build definitions on a Dockerfile to create small and compiler-free images. These images will only include application libraries, executables, and configurations. All compilations steps will be done on another image and we will just include the resulting files in a new one. We could also use external images in this process. We will only copy the required files for...