This article will teach you how to use SAML2 authentication with Spring Boot and Keycloak. Security Assertion Markup Language (SAML) is a standard for exchanging authentication and authorization identities between an Identity Provider (IdP) and a Service Provider. It is an XML-based protocol that uses security tokens with information about a principal. Currently, it is […] The post Spring Boot with SAML2 and Keycloak appeared first on Piotr's TechBlog ..read more

This article will teach you how to use the Eclipse JKube project to build images and generate Kubernetes manifests for the Spring Boot application. Eclipse JKube is a collection of plugins and libraries that we can use to build container images using Docker, Jib, or source-2-image (S2I) build strategies. It also generates and deploys Kubernetes […] The post Spring Boot on Kubernetes with Eclipse JKube appeared first on Piotr's TechBlog ..read more

This article will teach you, how to leverage SBOM support in Spring Boot to implement security checks for your apps. A Software Bill of Materials (SBOM) lists all your app codebase’s open-source and third-party components. As a result, it allows us to perform vulnerability scanning, license checks, and risk analysis. Spring Boot 3.3 introduces built-in […] The post SBOM with Spring Boot appeared first on Piotr's TechBlog ..read more

This article will teach you how to use Backstage in your app development and create software templates to generate a typical Spring Boot app. Backstage is an open-source framework for building developer portals. It allows us to automate the creation of the infrastructure, CI/CD, and operational knowledge needed to run an application or product. It offers a centralized software catalog and unifies all infrastructure tooling, services, and documentation within a single and intuitive UI. With Backstage, we can create any new software component, such as a new microservice, just with a few clicks ..read more

Bootify is an application generator for Spring Boot prototypes. How can we use this tool to build a Spring Boot CRUD app with Postgres as a database and Thymeleaf as a frontend? Although Thymeleaf almost has an epical age and nowadays many web applications are built as SPA, the library still serves its purpose extremely well. To make the user experience a little smoother, we also want to use HTMX with the boost function. We will create a simple database schema to manage books, authors and readers. Huge thanks to Piotr for the very kind opportunity to briefly ..read more

In this article, you will learn how to develop and deploy Java apps on Podman, Kubernetes, and OpenShift with odo. Odo is a fast and iterative CLI tool for developers who want to write, build, and deploy applications on Kubernetes-native environments. Thanks to odo you can focus on the most important aspect of programming – code. I have already written an article about that tool in my blog some years ago. However, a lot has changed during that time. Today, we will also focus more on Podman, and especially Podman Desktop, as an alternative to the Docker Desktop for local development. You will l ..read more

In this article, you will learn how to manage Kafka consumer offset with Spring Boot and Spring Kafka. An inspiration for preparing this article was the feedback I received after publishing the post describing concurrency with Kafka and Spring Boot. You were asking me questions related not only to concurrency but also to the consumer offset committing process. In the previous article, I focused mostly on showing that the way how the app handles Kafka messages may impact the overall performance of our system. I didn’t consider things like message duplicates or losing messages on the consumer si ..read more

This article will teach you how to dynamically create and rotate SSL certificates used in service-to-service communication with OpenShift and Spring Boot. We will achieve it with a single annotation on a Kubernetes service and the “SSL Bundles” mechanism introduced in Spring Boot 3.1. For generating the SSL on OpenShift, we will use the mechanism called “Service Serving Certificates”. It generates a certificate and key in PEM format. With Spring Boot 3.1 SslBundles, it won’t be a problem for our Java app, since it supports PEM-encoded certificates. The “Service Serving Certificates” mechanism ..read more

This article will teach you how to use Keycloak to enable OAuth2 for Spring Cloud Gateway and Spring Boot microservices. We will extend the topics described in my previous article and analyze some of the latest features provided within the Spring Security project. Our architecture consists of two Spring Boot microservices, an API gateway built on top of Spring Cloud Gateway, and a Keycloak authorization server. Spring Cloud Gateway acts here as an OAuth2 Client and OAuth2 Resource Server. For any incoming request, it verifies an access token before forwarding traffic to the downstream services ..read more

This article will teach you how to configure a hot reload of SSL certificates for the Spring Boot app running on Kubernetes. We will use the two features introduced in the 3.1 and 3.2 versions of the Spring Boot framework. The first of them allows us to leverage SSL bundles for configuring and consuming a custom SSL trust material on both the server and client sides. The second one makes it easy to hot reload SSL certificates and keys for embedded web servers in the Spring Boot app. Let’s see how it works in practice! In order to generate SSL certificates on Kubernetes we will use cert-manager ..read more