Book Image

Scala Microservices

By : Selvam Palanimalai, Jatin Puri
Book Image

Scala Microservices

By: Selvam Palanimalai, Jatin Puri

Overview of this book

<p>In this book we will learn what it takes to build great applications using Microservices, the pitfalls associated with such a design and the techniques to avoid them. </p><p>We learn to build highly performant applications using Play Framework. You will understand the importance of writing code that is asynchronous and nonblocking and how Play leverages this paradigm for higher throughput. The book introduces Reactive Manifesto and uses Lagom Framework to implement the suggested paradigms. Lagom teaches us to: build applications that are scalable and resilient to failures, and solves problems faced with microservices like service gateway, service discovery, communication and so on. Message Passing is used as a means to achieve resilience and CQRS with Event Sourcing helps us in modelling data for highly interactive applications. </p><p>The book also shares effective development processes for large teams by using good version control workflow, continuous integration and deployment strategies. We introduce Docker containers and Kubernetes orchestrator. Finally, we look at end to end deployment of a set of scala microservices in kubernetes with load balancing, service discovery and rolling deployments. </p><p></p>
Table of Contents (12 chapters)

Installation of K8s

Before we deploy our K8s configurations, we need a kubernetes cluster to connect to. Follow the instructions here to set up the kubernetes cluster using kubeadm at https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/. I recommend that you use a cloud account for this example even though it might cost a little bit.

Every cloud provider gives out free accounts. They are worth checking out at https://aws.amazon.com/free/, https://cloud.google.com/free, and https://azure.microsoft.com/en-us/free/.

If the installation was successful, we will have to copy the admin kubeconfig file. It is usually located at /etc/kubernetes/admin.conf.

For simplicity, we will not do any role-based access control (RBAC) for this cluster. We will just use the admin kubeconfig file to do all our deployments. This is not a recommended practice in production.

You could use...