This book is much more than just the fundamentals of OpenShift. It's about the past, present, and the future of microservices and containers in general. In this book, we are going to cover OpenShift and its surroundings; this includes topics such as the fundamentals of containers, Docker basics, and studying sections where we will work with both Kubernetes and OpenShift in order to feel more comfortable with them.

During our OpenShift journey, we will walk you through all the main and most of the advanced components of OpenShift. We are going to cover OpenShift security and networking and also application development for OpenShift using the most popular and built-in OpenShift DevOps tools, such as CI/CD with Jenkins and Source-to-Image (S2I) in conjunction with GitHub.

We will also learn about the most critical part for every person who would like to actually implement OpenShift in their company—the design part. We are going to show you how to properly design and implement OpenShift, examining the most common mistakes made by those who have just started working with OpenShift.

The chapter is focused on container and Docker technologies. We will describe container concepts and Docker basics, from the architecture to low-level technologies. In this chapter, we will learn how to use Docker CLI and manage Docker containers and Docker images. A significant part of the chapter is focused on building and running Docker container images. As a part of the chapter, you are asked to develop a number of Dockerfiles and to containerize several applications.

In this chapter, we will look at the following:

• Containers overview
• Docker container architecture
• Understanding Docker images and layers
• Understanding Docker Hub and Docker registries
• Installing and configuring Docker software
• Using the Docker command line
• Managing images via Docker CLI
• Managing containers via Docker CLI
• Understanding the importance of environment variables inside Docker containers
• Managing persistent storage for Docker containers
• Building a custom Docker image