This chapter will provide an introduction to containers, dockerizing the services built in the previous chapter, writing the Dockerfile and orchestrating the containers using docker-compose, and providing orchestration examples in Kubernetes.

In the previous chapter, we learned about microservice architecture and its advantages and challenges. One of the major challenges in the microservice-distributed application is the deployment of several microservices across multiple machines (VMs). How will they share common resources of VMs? In production, deploying and managing a system composed of many independent services is an operational complexity.

In microservice architecture, you create and deploy services independently, and you have to re-test your services after deployment on the same VMs. A microservice wouldn't impact on the other microservices, but you could never really guarantee that because the service is independent of the other services, it is using common resources of VMs.

In the favor of microservice architecture, containerized deployment is the topping on the pizza. The microservice is already autonomous by its functional service, but the containerization makes microservices more autonomous by self-containing the underlying infrastructure. So, containerization is making the microservices cloud-neutral.

In this chapter, we will introduce the containerized deployment of microservices and concepts of virtual machine images. Readers will get an understanding of building Docker images for microservices, which are developed with Spring Boot and Spring Cloud. We will also explore how to deploy Docker images in production-like environments, and how to manage and maintain these Docker images.

By the end of this chapter, you will have a better understanding of containerization and how to containerize a microservice developed with Spring Boot and Spring Cloud.

This chapter will cover the following points:

• Introducing containers in the microservice architecture
• Getting started with Docker
• Dockerizing any Spring Boot application
• Writing Dockerfile
• Using docker-compose
• Writing the docker-compose file
• Orchestration using docker-compose
• Introducing Kubernetes
• Orchestration using Kubernetes

Let's look at these topics in detail.