Spring Cloud - Everything you need to know

So you've heard about Spring Cloud and how it can help build microservice based applications. Before you try Spring Cloud for yourself, read more about this framework, its relationship with Spring Boot, its features, and more.

We've simplified the basics of Spring Cloud so you can improve development outcomes and create more successful applications. 

What is Spring Cloud?

Let's start by looking at how Spring Cloud describes itself:

"Spring Cloud provides tools for developers to quickly build some of the common patterns in distributed systems. Coordination of distributed systems leads to boiler plate patterns, and using Spring Cloud developers can quickly stand up services and applications that implement those patterns."

In other words, Spring Cloud is a framework for building strong cloud and microservice applications.

It can help developers solve problems when moving to a distributed environment—a computing environment where components are spread across many different computers. 

Developers might use Spring Cloud for:

• Configuration management
• Intelligent routing
• Service discovery 
• Circuit breakers
• Control bus
• Distributed sessions
• Global locks
• One-time tokens
• Leadership election 
• Service discovery via Netflix Eureka, a REST API-based middleware for the discovery of web applications
• Load balancing via the client-side load balancer Ribbon, which lets developers manage the behavior of HTTP and TPC clients 
• Fault tolerance via Spring Cloud Netflix Hystrix
• Routing management in microservice architectures via the application server Zuul

Spring Cloud lets developers build applications for internet browsers, mobile devices, and the Internet of Things (IoT) via an API gateway.

An infographic illustrates the Spring Cloud architecture. You can see the various components of Spring Cloud, such as microservices, distributed tracing, and an API gateway. 

What problems does Spring Cloud solve?

More developers are using microservices to build applications. This software approach splits the components of applications into small services that operate independently — also known as service boundaries.

Spring Cloud helps developers build a successful microservices architecture by automating administrative tasks and improving fault tolerance. 

It’s also important to discuss the relationship between Spring Boot and Spring Cloud:

• Spring Boot is the open-source Java framework that helps create microservices. It lets developers concentrate on code instead of setting up and configuring microservice environments. It also provides various development tools that make applications more successful. 
• Spring Cloud is a component of Spring Boot. It lets developers tear down and create complicated patterns in distributed environments. It also centralizes configuration management and offers more security than open-source Spring Boot.
• Both Spring Boot and Spring Cloud are part of the Spring Framework. Developers will typically use both technologies to create and maintain microservices. 

What you should know about Spring Cloud

The first version of Spring Cloud—Spring Cloud Zookeeper—came out in April 2007. There have been multiple versions—or 'release trains'—of the framework since then, including the now-retired Spring Cloud Dalston, Spring Cloud Finchley, and Spring Cloud Greenwich.

The most recent iteration is Spring Cloud 2021.0.x, also known as Spring Cloud Jubilee.

The complicated thing about Spring Cloud is that it's an umbrella project with many different release cadences and independent projects.

When using Spring Cloud with Spring Boot, you'll need to choose the right version of the framework to create a new project, and we’ll explore this further later in this post.

How to use Spring Cloud 

You can start a new Spring Cloud project by heading to start.spring.io. Here, you can choose your version of Spring Boot and the Spring Cloud projects you want to work on.

That will add the relevant version of Spring Cloud BOM (bill of materials)—a project with a series of pre-determined dependencies—to your Maven or Gradle file.

Maven and Gradle are 'build tools' that automate tasks associated with transforming your application's source code into a publishable artifact.

Developers can transform application source code themselves, but this is a long and laborious process requiring lots of code compiling. 

You can see that Spring Boot and Spring Cloud complement each other, so we recommend you understand both of them before starting a new project.

If you want to add Spring Cloud to an existing Spring Boot app, you will need to decide on the correct version of Spring Cloud to use. You can find out which Spring Cloud version works with which Spring Boot version here.

Spring Cloud Features

Here are some features of Spring Cloud:

Spring Cloud Config

Spring Cloud Config (or Spring Cloud Config Server) provides client-side and server support for configuration in a distributed system.

It gives developers a centralized location to handle external application properties across environments. Spring Cloud Config:

• Offers an HTTP resource-based API for name-value pairs or YAML content
• Can encrypt/decrypt symmetric or asymmetric property values
• Embeds in a Spring Boot application

Spring Cloud Stream

Spring Cloud Stream builds scalable event-driven microservices through shared messaging systems. It supports binder implementations for platforms such as:

• RabbitMQ
• Apache Kafka
• Amazon Kinesis

Spring Cloud Netflix

Spring Cloud Netflix comes with Netflix OSS integrations for Spring Boot applications. It binds to and autoconfigures the Spring Environment and other programming model idioms.

Spring Cloud Gateway

Spring Cloud Gateway is a library for creating API gateways on Spring WebFlux, allowing developers to route to APIs and improve resiliency, metrics, security, and monitoring. 

Features of Spring Cloud Gateway include:

• Circuit breaker integration
• Predicate and filter writing
• Path rewriting
• Request rate limiting

Spring Cloud Bus

Spring Cloud Bus connects distributed system nodes with a message broker, allowing developers to broadcast configuration changes and management instructions.

Other features of Spring Cloud include:

• Spring Cloud Sleuth
• Spring Cloud Contract
• Spring Cloud Data Flow

Spring Cloud security

Because Spring Boot is an open-source framework, it can increase the risk of security vulnerabilities. Using Spring Cloud in conjunction with Spring Boot can secure application development.

Here are some of the security features of Spring Cloud: 

• Spring Cloud uses a declarative model that developers can configure centrally or externally when implementing systems of remote components. 
• Developers can relay SSO tokens from a front-end service to a back-end service using a Zuul proxy server
• Developers can relay tokens between one resource server and another
• Developers can configure downstream authentication using a Zuul proxy server

Final word

Spring Cloud solves the problems of moving to a distributed environment, helping you create more successful applications.

Use Spring Cloud with Spring Boot to transform your microservices architecture! You can get more value from the Spring framework when your engineers and developers adopt best practices for application development. 

Reach out to Adservio for more insights about how Spring Cloud can help you create strong cloud and microservice applications. We can streamline operations and reduce the complexities involved when implementing this framework into your business.