Spring Cloud Config : Using Git Webhook to Auto Refresh the config changes with Spring Cloud Stream, Spring Cloud Bus and RabbitMQ (Part 3)

 

You can refer the previous parts of this article as follows.

Click here for Part 1 

Click here for Part 2

 

The Problem

In the previous article (Part 2 of this series),  we have discussed how to use Spring Cloud Bus to broadcast the refresh event ( /actuator/bus-refresh) across all the connected services. In here the refresh event should be manually triggered on any service that is connected to the Spring Cloud Bus. (You can select any service as you wish. The only requirement is that it should connect to the Spring Cloud Bus).

The main problem here is that whenever the properties are changed, the refresh event should be manually triggered. Even if it is for just one service, it is still a manual process. What will happen if the developer forgets to manually trigger the refresh event after updating the properties in the remote repository? 

Wouldn’t be nicer if there is any way to automate this refresh event triggering  whenever the remote repository is changed. In order to achieve this, the config server may need to listen for the events of the remote repository.  This can be done with webhook event feature provided by the remote repository providers.

 

 

The Solution

Here is the architecture of the proposed solution.

 

Untitled Diagram (10).png

Continue reading “Spring Cloud Config : Using Git Webhook to Auto Refresh the config changes with Spring Cloud Stream, Spring Cloud Bus and RabbitMQ (Part 3)”

Spring Cloud Config : Refreshing the config changes with Spring Cloud Bus (Part 2)

You can refer the part 1 of this article as follows.

Click here for Part 1 

 

The Problem

The previous article (click here to visit it) has described how to use Spring Cloud Config Server as a centralized location for keeping the configuration properties related to the application services (microservices).  The application services will act as Config Clients who will communicate with Config Server to retrieve the properties related to them.

If any property is changed, the related service need to be notified by triggering a refresh event with Spring Boot Actuator (/actuator/refresh). The user will have to manually trigger this refresh event. Once the event is triggered, all the beans annotated with @RefreshScope will be reloaded (the configurations will be re-fetched) from the Config Server.

In a real microservice environment, there will be a large number of independent application services. Therefore is it not practical for the user to manually trigger the refresh event for all the related services whenever a property is changed.

Continue reading “Spring Cloud Config : Refreshing the config changes with Spring Cloud Bus (Part 2)”

Spring Cloud Bus: Centralizing Message Broker (RabbitMQ or Kafka) connection properties with Spring Cloud Config Server

 

The Problem

In previous article, we have discussed how to use Spring Cloud Bus to broadcast the  configuration property changes (occurred in the Spring Cloud Config Server) across distributed services.

Spring Cloud Bus links or connects the distributed services through a lightweight message broker such as Kafka or RabbitMQ.  whenever the refresh event is triggered in one service, Spring Cloud Bus will broadcast the refresh event across multiple services (known as Config Clients).

Therefore every Config Client should connect to the underlying message broker (that can be either RabbitMQ or Kafka) of the Spring Cloud Bus to listen for the refresh events published/broadcasted. This will lead every Config Client to keep a connection with message broker implemented in the Spring Cloud Bus.

Continue reading “Spring Cloud Bus: Centralizing Message Broker (RabbitMQ or Kafka) connection properties with Spring Cloud Config Server”

Microservices: Introduction to Spring Cloud Config Server and Config Client (Part 1)

I am a big fan of Spring family. In this article, i am going to explain how to use Spring Cloud Config Server for externalizing and versioning the configuration properties of your microservice.

 

The Problem!

The one of the most challenge in the distributed application environment (or rather microservices environment) is to maintain and manage the configuration related properties in the microservices.

In microservice environment, there may be hundred of isolated services and each service may have different configuration properties depending on the environment (eg:- qa, dev, prod, uat etc…).

Some of the properties are shared among services and some of the properties are specific/private to that service. Those properties may be changed or updated in later and the update need to be reflected. If the configuration maintaining and management is not properly planned, you have to face for a difficult time when those update happens.

Continue reading “Microservices: Introduction to Spring Cloud Config Server and Config Client (Part 1)”

Spring Boot Test and Spring Security: Perform Http Basic Authentication with TestRestTemplate

 

What is HTTP Basic Authentication?

If you want to refresh your knowledge on HTTP Basic Authentication, please click here to refer my article on that.

Here i am going to show you how to execute spring test cases on REST endpoints that are secured with Spring Security and required HTTP Basic Authentication.  Here we are going to use the TestRestTemplate as the REST client for invoking REST endpoints.

 

TestRestTemplate

TestRestTemplate is a convenience alternative to Spring’s RestTemplate that is useful in integration tests. If you use the @SpringBoootTest annotation , with one of the following webEnviroment attribute, you can use fully configured TestRestTemplate in your Test class.

@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
                        OR
@SpringBootTest(webEnvironment = WebEnvironment.DEFINED_PORT)

 

There are different ways that can be used to perform Basic Authentication with TestRestTemplate.

  1.  Authentication headers
  2.  ‘withBasicAuth’ method
  3.  With Authenticated TestRestTemplate object.

Lets look at each of those approaches in detailed as follows.

Continue reading “Spring Boot Test and Spring Security: Perform Http Basic Authentication with TestRestTemplate”

Spring Data JPA : Auditing with @CreatedBy, @CreatedDate, @LastModifiedBy and @LastModifiedDate

 

What is database Auditing?

database auditing means that keeping a track and log of the events (specially create and update) associated with the persistent entities. It keeps a track of who created or changed an entity and when the change happened.

I have seen projects storing these things manually. Doing so becomes very complex because you will need to write it completely on your own, which will definitely require lots of code — and lots of code means less maintainability and less focus on writing business logic.

But why should someone need to go to this path when both JPA and Hibernate provide automatic auditing, which we can be easily configured in your project? Basically the following information are maintained with database auditing.

  • created user (who created)
  • created date (when created)
  • last updated user (who updated)
  • last updated date (when updated)

 

Auditing with Spring Data JPA

Spring Data JPA provides some set of convenient and useful annotations for database auditing. It helps to keep a track of who did the change and when it was done.

Here in this article, I will discuss how we can configure JPA to automatically persist the audit related columns (created and modified information) for any entity with following annotations. (All these annotations are owned by the Spring Data JPA)

  • @CreatedBy
  • @CreatedDate
  • @LastModifiedBy
  • @LastModifiedDate

Continue reading “Spring Data JPA : Auditing with @CreatedBy, @CreatedDate, @LastModifiedBy and @LastModifiedDate”

ReactJs : First ReactJs Application

 

What is ReactJs?

React is a Javascript library, by Facebook, that is used for building user interfaces. It helps to build super fast and reactive web applications that runs on user’s browser.  It uses ES6 based javascript syntaxes.

ReactJs builds the UI (User Interface) based on the concept called Component. The UI view is split into reusable and manageable small segments called components. The ReactJs renders the user view based on those components.  Therefore ReactJs is all about splitting the UI into components and render the UI based on those components.

 

What is NPM (Node Package Manager) ?

NPM (Node Package Manager) is a package manager for the JavaScript programming language. It is the default package manager used in NodeJs.  It enables the path of accessing thousands of  reusable javascript libraries for your project.

NPM was initially developed as the package manager of the NodeJs. Therefore NPM is distributed (available) with the NodeJs installation.

 

NPM (Node Package Manager) and NodeJs Server

Here we are going to create a project that manage its dependencies with NPM.  Therefore if you dont have the NPM installed in you development environment, please visit the NodeJs website and install the NodeJs.  If you instal the NodeJs, you will get both NPM (Node Package Manager) and NodeJs Server. Since the Node Server is available,  it can be used as a development server to deploy the project files.

Continue reading “ReactJs : First ReactJs Application”