Lydtech Reference Projects

Introduction

At Lydtech we have put together a wide array of reference projects. From Kafka to Kubernetes to Kotlin, and from Mongo to Micronaut to Monitoring - and everything in between - these form an excellent starting point when researching a new technology. These projects often underpin our blog articles on the technology, language or pattern that give more insight and detail, and these articles are referenced from the project’s Readme file. This article collates all the available projects, with a brief description of each and a link to their repository on our Github.

Reference Projects

Spring Boot

Spring Boot Demo With REST Demo Spring Boot application exposing a REST API to enable performing of CRUD operations on an entity.

Spring Boot Demo With Postgres Spring Boot application demonstrating using Postgres as the datatabase for reading and writing records.

Spring Boot Demo With MongoDB Spring Boot application demonstrating using MongoDB as the datatabase for reading and writing records.

Spring Boot Demo With Elasticsearch Spring Boot application demonstrating using Elasticsearch for reading and writing records.

Spring Boot Demo With React Front End Spring Boot application with a React front end that allows the user to list, add, edit and delete items.

Micronaut

Micronaut & Kotlin Demo with a REST API Demo Micronaut application written in Kotlin exposing a REST API to enable performing of CRUD operations on an entity. The application stores entities in memory.

Micronaut & Kotlin Demo with a Postgres Database Demo Micronaut application written in Kotlin exposing a REST API to enable performing of CRUD operations on an entity that is persisted to Postgres.

Micronaut & Kotlin Demo Integrating With Kafka Demo Micronaut application written in Kotlin that integrates with Kafka. The application consumes events from an inbound topic, and emits an outbound event for each.

Micronaut & Java Demo with a REST API Demo Micronaut application written in Java exposing a REST API to enable performing of CRUD operations on an entity. The application stores entities in memory.

Micronaut & Java Demo with a Postgres Database Demo Micronaut application written in Java exposing a REST API to enable performing of CRUD operations on an entity that is persisted to Postgres.

Micronaut & Java Demo Integrating With Kafka Demo Micronaut application written in Java that integrates with Kafka. The application consumes events from an inbound topic, and emits an outbound event for each.

Kafka

Kafka Spring Boot Consume & Produce Demo Spring Boot application demonstrating usage of Kafka consumers and producers.

Kafka Spring Boot Batch Consume Demo Spring Boot application demonstrating batch consume behaviour when a message throws an exception.

Kafka Spring Boot Chaos Testing Demo Spring Boot application demonstrating chaos testing using Conduktor Gateway to simulate failure scenarios with Kafka.

Kafka Consumer Retry Demo Spring Boot application demonstrating Kafka consumer retry.

Kafka Spring Boot Retry Topics Demo Spring Boot application demonstrating Kafka non-blocking retry with Spring retry topics.

Kafka: A Pattern For Retry With Non-Blocking Delay Spring Boot application demonstrating usage of a pattern for Kafka consumer retry with non-blocking delay.

Kafka Idempotent Consumer With DynamoDB Spring Boot application demonstrating the Kafka Idempotent Consumer pattern using DynamoDB as the backing store for the event deduplication.

Kafka Spring Boot JSON Serialization Demo Spring Boot application demonstrating serializing and deserializing messages in that are in the JSON format.

Kafka Kubernetes Demo Spring Boot application used to demonstrate deployment to Kubernetes along with Kafka and Zookeeper.

Kafka Spring Boot Message Compression Demo Spring Boot application demonstrating Kafka message compression.

Kafka Spring Boot Message Keys Demo Spring Boot application demonstrating use of Kafka message keys, partitions, and message ordering.

Kafka Spring Boot Metrics Demo Spring Boot application demonstrating Kafka monitoring and JMX metrics utilising Conduktor Platform and Confluent Control Center.

Kafka TLS Example Project Demonstrating securing Kafka with Mutual TLS and ACLs

Kafka Spring Boot SASL PLAIN Demo Spring Boot application demonstrating authenticating with Kafka using SASL PLAIN.

Kafka Spring Boot Schema Registry & Avro Demo Spring Boot application demonstrating usage of the Kafka Schema Registry with Avro serialisation.

Kafka Transactions Project Spring Boot application demonstrating usage of the Kafka Transactional API to achieve exactly-once messaging semantics.

Flink Integration with Kafka Demo Demonstrates running a Flink job that integrates with Kafka using the Kafka connector.

Kafka Connect

Kafka Idempotent Consumer & Transactional Outbox Spring Boot application demonstrating the Kafka Idempotent Consumer pattern and Transactional Outbox pattern with Debezium (Kafka Connect) used for Change Data Capture (CDC) to publish outbound events.

Kafka Connect: Debezium, Postgres and Spring Boot Demo Spring Boot application demonstrating the Transactional Outbox pattern using Debezium (Kafka Connect) for Change Data Capture (CDC) to publish outbound events to Kafka from Postgres.

Kafka Connect: Debezium, MongoDB and Spring Boot Demo Spring Boot application demonstrating using Kafka Connect for Change Data Capture (CDC) to publish outbound events to Kafka from MongoDB.

Kafka Streams

Kafka Streams Project Spring Boot application demonstrating usage of the Kafka Streams.

Kafka Streams Windowing Examples Demonstrate the basic behaviours and differences in the Windowing options for Kafka Streams. Explores testing windowing types, and demonstrates deploying on Kubernetes.

KafkaJS

KafkaJS Consume and Produce Demo Demonstrating integration testing a KafkaJS Typescript application using Testcontainers and Docker.

KafkaJS Example Sending and receiving events from Kafka with a Typescript application using KafkaJS.

Security

Simple REST API Project with Basic Security Demonstrating securing a REST API with basic security.

REST API Project with Authentication / Authorisation provided by Keycloak Demonstrating authentication and authorisation using Keycloak.

REST API project with Authentication / Authorisation provided by Keycloak - Generic Spring Security Configuring authentication/authorisation via Keycloak using generic spring security features.

Simple React OIDC / OAuth client A SPA that can be used as an OAuth client to perform the Authorisation Code Grant flow and call a resource server.

Simple React OIDC / OAuth Resource Server Spring Boot application that can be used as an OAuth Resource Server.

Spring Boot OAuth Client Application Spring Boot application that can be used as an OAuth client / resource server as a 'confidential client'

Patterns & Best Practices

Monitoring And Alerting Demonstrating the monitoring and alerting of Kafka, Postgres and a Spring Boot application using Prometheus, Grafana and Alertmanager.

Logging Demo With Graylog Demonstrating sending logs from a Spring Boot application to Graylog.

Lambda Flyway Migrator A Java project designed to be executed as an AWS Lambda. Performs a 'Flyway migrate' on a specified database.

Circuit Breaker & Failover Example Using Resilience4j Spring Boot application demonstrating Resilience4j for managing fault tolerance with failover and circuit breaker

Testing

Component Test Framework - Getting Started A simple Spring Boot application showcases the component-test-framework for component testing.

Component Test Framework Example Service Example service with the component test framework used within a single module project.

Component Test Framework Example Multi Module Project Example service with the component test framework used as part of a multi module project.