Category: Microservices

How do i check logs of a docker container ?

To demonstrate this, i have a sample spring boot application which prints log every 1000 milliseconds (1 second) @RestController public class RandomLoggerResource { private static final Logger logger = LoggerFactory.getLogger(RandomLoggerResource.class); private Random random = new Random(); @Scheduled(fixedRate = 1000) public void logRandomMessage() { int randomInt = random.nextInt(); String randomMessage = "Generating a Random integer every … Continue reading How do i check logs of a docker container ? →

How do you add custom response headers in a Spring Boot application?

To add custom response headers in a Spring boot application use ResponeEntity class. Set the values using HttpHeader object. Set the header object in response entity To set a response header for all the response , implement a Filter class and set the header in the ServletResponse class Code Snippet @Component public class ResFilter implements … Continue reading How do you add custom response headers in a Spring Boot application? →

Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 2

In the PART 1 of this blog series, we deployed a PostgreSQL database on minikube. In this part, we will deploy spring boot application . I have mentioned in PART 1 , how to dockerize and upload the order service to docker registry. The application.properties of the service , will get the details of database … Continue reading Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 2 →

Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 1

How to deploy a containerized spring boot application , with PostgreSQL as database on minikube. This post will also share details on how to initialize the database with tables and data during the initialization process. Will use a spring boot application order service with a REST endpoint to fetch customer details GET /customers It uses … Continue reading Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 1 →

Java microservices with GraalVM

Microservice is a trending and popular architecture to build applications as it allows organizations to be agile and adopt DevOps and continuous testing practices.Spring Boot is a very popular technology choice to build java based microservices, but it consumes a good amount of memory and spring's runtime reflection approach leads to longer startup times as … Continue reading Java microservices with GraalVM →

GraalVM : A JVM written in Java for high performant applications !!

The HotSpot JVM which i shared in the previous blog is suited and optimized for traditional on-premise based applications to provide high throughput and stability.New modern applications are being built for cloud as distributed systems developed using microservices, event driven, asynchronous and reactive design which should scale quickly and efficientlyHotSpot JVM and JIT compiler is … Continue reading GraalVM : A JVM written in Java for high performant applications !! →

What is JWT and why do we need it in a microservices based application?

JWT (JSON Web Token) is a very popular way to do user authorization in microservices. It is a standard which is used to create access tokens for an application and enables secure communication between between two parties. The Industry standard specification RFC7519 outlines how information in JWT should be structured. It is widely used in … Continue reading What is JWT and why do we need it in a microservices based application? →

Execute multi-container applications (Spring boot & PostgreSQL)

Use Case Run a dockerized spring boot application which has dependency on PostgreSQL docker containerInitialize the database with data while its getting createdMount an external volume so that the data does not get lost when container exits Solution:Step 1: Build a micro service using spring boot to be containerizedClone the following spring boot implementationhttps://github.com/rajeshsgr/order-svcThe example … Continue reading Execute multi-container applications (Spring boot & PostgreSQL) →

What is Observability in IT ?

In control systems engineering, observability is defined as a measurement of how well a system's internal states could be inferred from its external outputs. Meaning a system is considered observable if we can determine the behavior of the entire system in a finite time period from the system output. A system whose output doesn't generate … Continue reading What is Observability in IT ? →

Service virtualization with spring boot microservices

Service Virtualization mimics or simulates behaviors of components that are unavailable or difficult to access while testingMicroservices applications are generally composed of multiple services. During the testing phase when the dependent services are not available, service virtualization technique allows to mimic the unavailable service and continue the tests even when the actual service is unavailable.During … Continue reading Service virtualization with spring boot microservices →