Keycloak

 Keycloak is an open source Identity and Access Management solution targeted towards modern applications and services.

Keycloak offers features such as Single-Sign-On (SSO), Identity Brokering and Social Login, User Federation, Client Adapters, an Admin Console, and an Account Management Console.

Below are keycloak features:

1)Multiple protocols support

2)SSO support

3)Offers Web based GUI

4)External Identity Source Sync

In case when your client currently has some type of user database, Keycloak allows us to synchronize with such database. By default, it supports LDAP and Active Directory but you can create custom extensions for any user database using Keycloak User storage API.

4)Identity Brokering

Keycloak can also work as a proxy between your users and some external identity provider or providers. Their list can be edited from Keycloak Admin Panel.

5)Social Identity Providers

Additionally, Keycloak allows us to use Social Identity Providers. It has built-in support Google, Twitter, Facebook, Stack Overflow but, in the end, you have to configure all of them manually from admin panel. 

6)Customizations

Currently  Keycloak supports following distributions.

1)server

2)Docker Image

3)Operator

Link: https://www.keycloak.org/

Introduction to SpringBoot

Spring Boot is an open-source micro framework maintained by a company called Pivotal.

 It provides Java developers with a platform to get started with an auto configurable production-grade Spring application. With it, developers can get started quickly without losing time on preparing and configuring their Spring application.

Spring Boot is built on top of the Spring framework, and it comes with many dependencies that can be plugged into the Spring application.

Some examples are Spring Kafka, Spring LDAP, Spring Web Services, and Spring Security. However, developers have to configure each building brick themselves using a lot of XML configuration files or annotations.

In Spring Boot, there is no requirement for XML configuration (deployment descriptor). It uses convention over configuration software design paradigm that means it decreases the effort of the developer.

Features:

• Create stand-alone Spring applications
• Embed Tomcat, Jetty or Undertow directly (no need to deploy WAR files)
• Provide opinionated 'starter' dependencies to simplify your build configuration
• Automatically configure Spring and 3rd party libraries whenever possible
• Provide production-ready features such as metrics, health checks, and externalized configuration
• Absolutely no code generation and no requirement for XML configuration

Setup Spring Boot:

• Setup Java JDK from Oracle’s official site.
• Download and Setup STS(Spring Tools Suite).
• Start a new spring starter project
• Click on File -> New -> Spring starter project
• Fill the appropriate details and add dependency and finish.
• Edit the application properties.
• Run the main file as a Java application.

Spring Cloud

Developing distributed systems can be challenging. Complexity is moved from the application layer to the network layer and demands greater interaction between services.

Making your code "cloud-native" means dealing with 12-factor issues such as external configuration, statelessness, logging, and connecting to backing services.

The Spring Cloud suite of projects contains many of the services you need to make your applications run in the cloud.

Spring Cloud provides tools for developers to quickly build some of the common patterns in distributed systems (e.g. configuration management, service discovery, circuit breakers, intelligent routing, micro-proxy, control bus, one-time tokens, global locks, leadership election, distributed sessions, cluster state). 

Features of Spring Cloud:

• Distributed/versioned configuration
• Service registration and discovery
• Routing
• Service-to-service calls
• Load balancing
• Circuit Breakers
• Global locks
• Leadership election and cluster state
• Distributed messaging

Spring Cloud Netflix:

Spring Cloud Netflix features:

• Service Discovery: Eureka instances can be registered and clients can discover the instances using Spring-managed beans
• Service Discovery: an embedded Eureka server can be created with declarative Java configuration
• Circuit Breaker: Hystrix clients can be built with a simple annotation-driven method decorator
• Circuit Breaker: embedded Hystrix dashboard with declarative Java configuration
• Declarative REST Client: Feign creates a dynamic implementation of an interface decorated with JAX-RS or Spring MVC annotations
• Client Side Load Balancer: Ribbon
• External Configuration: a bridge from the Spring Environment to Archaius (enables native configuration of Netflix components using Spring Boot conventions)
• Router and Filter: automatic registration of Zuul filters, and a simple convention over configuration approach to reverse proxy creation