Microservices are a form of JHipster application that does not have a front-end (the Angular front-end must be created on a gateway) and is set up, found, and managed using the JHipster Registry. JHipster is an open-source project that merges three incredibly effective web development structures: Spring Boot, Angular, and Bootstrap.
Bootstrap was one of the first widely used web component structures. Its main selling point was that it only needed a small amount of HTML and it worked! Bootstrap demonstrated to many in the Java community how to create web parts. It, like Apple’s Human Interface Rules for iOS apps, leveled the field of play in HTML/CSS advancement.
JHipster is essentially a Yeoman generator. Yeoman is a code creator that you can use with the yo command to create entire apps or use parts of an app. Yeoman generators endorse the “Yeoman workflow,” as defined by the Yeoman team. It is an opinion-based client-side tool collection that can assist developers in quickly creating beautiful web apps. It takes care of providing everything required to get up and running without the usual aches and pains related to manual configuration.
In summary, JHipster is a tool for generating code that can be used to generate web apps, microservices, Kubernetes implementation files, Jenkins CI/CD files, and cloud integrations. This tool is extremely useful for developers because it allows them to quickly generate code while avoiding the creation of boilerplate code, saving them 30% of the time.
JHipster facilitates both front-end Angular/React/Vue.js code and back-end Spring Boot code. Here, we will be discussing the microservices stack generated and supported by JHipster.
Understanding How JHipster Supports Microservices
Microservices are self-contained, modular implementable parts divided into business domain systems and business capabilities that are efficient, scalable, and quick to deploy.
Microservices are made up of many different components including Security, Service registry, Fault tolerance, Service discovery, Resiliency, and Health checks. JHipster supports the following Microservices parts to achieve the above-mentioned constituents.
1. JHipster Registry
This is the service registry, where various microservices can enroll and learn about the setup. Dashboards for tracking and health checks are also provided by the registry. The JHipster Registry is made up of two parts: Spring Cloud Config Server and Netflix Eureka.
a) Netflix Eureka
Eureka allows for the dynamic registration and discovery of services. Eureka maintains a single centralized registry where new microservices can be registered and delisted when they fail. The registry keeps up-to-date information about the available offerings and their metadata. When a service is enrolled to the Eureka server, it sends its heartbeats, and when that no longer happens, the service is removed from the registry.
Eureka offers dynamic discovery, in which clients search for the service registry to obtain service information such as the service’s URL and connect via the URL.
b) Spring Cloud Config Server
This serves as a centralized repository for managing all of the microservices’ attributes and setups. Microservices can link to the cloud-config service to obtain configuration information. A Rest API can also be used to access the configuration service.
2. JHipster API Gateway
JHipster provides Gateway, which serves as a single access point to the services. Fault tolerance, request and response transformation, filtering, API security, routing, throttling, and caching are all provided by the gateway.
JHipster gateway merges with Zuul for API Gateway functionality and Hystrix for robustness and circuit breaker functionality. JHipster is searching for Resilience4J assimilation for circuit breaker functionalities because Hystrix support will be excluded in the future.
Hystrix or Resilience4J prevents cascading breakdowns in distributed systems, facilitates fallback services, and manages system latency.
JHipster API Gateway will collaborate with JHipster Registry to find services and perform HTTP requests load balancing with Spring Cloud Load Balancer.
3. JHipster Control Center
The control center keeps track of and manages apps. The control center has the following capabilities:
Instances include an app instances list; when a service is enrolled in the JHipster Registry, it appears in the list of instances. It also includes a dashboard where you can view the list.
A Micrometer manages the metrics, which track system metrics such as JVM, HTTP requests, cache utilization, and database links.
c) Health Checks
The health checks are assimilated with Spring Actuator to determine the status of services’ health.
Log back is merged with logs to locate the logs of the running application.
e) API documentation
Swagger API documentation is provided by API documentation.
4. Security with JWT
JWT is a stateless security method that can be distributed across multiple servers. It is JHipster Microservices’ basic security setting. Signature, Payload, and Header are all provided by JWT. The token contains all of the client session data. JWT does not support server-side session management. OAuth 2.0 supports JWT for secure transmission.
5. JHipster UAA Microservices Security
JHipster UAA is a microservice composing and user accounting tool that works with OAuth2. OAuth2 is a structure for authorization that can be used for centrally controlled identity management. JHipster UAA has an OAuth2 end-point that returns an authentication code-based access token.
The token allows for fine-grained network access to Rest-based services. The authentication server and the resource server are combined to form UAA.
Conclusion for Microservices with Jhipster
When developing a Microservice framework with JHipster, we’ll have to create and implement a minimum of three projects: a minimum of one Microservice Application, a Microservice Gateway, and a JHipster Registry.
Beginning a Microservice Architecture project with JHipster is simple; all we must do is to build as many Microservice Apps as required and one Microservice Gateway, and we’re good to go. Contact us to learn more about the framework and development strategies of Microservices with Jhipster.
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