Moving to jvwilge.github.io

From now (Aug 30, 2021) new articles will be published on jvwilge.github.io because I swear to much when adding code snippets to WordPress (and it is ad-free).

Running your java integration tests with Gradle and docker-compose with only one command (optionally with Bitbucket Pipelines)

This article will show you how to run your java integration tests with Docker containers running via docker-compose by only running the Gradle build-step and without needing to fiddle with Docker or docker-compose.
As an addition I’ll also show how to do it on Bitbucket Pipelines, but of course you can skip this step.

Using a ConnectableFlux to do background batching on elasticsearch

We have a Project Reactor application which is a bit brittle on refactorings. The load on our elasticsearch cluster is pretty high due to many single get/insert by id’s. Adding batch read by id was so much work that I was looking for a different solution. I eventually came up with a solution using a ConnectableFlux.

Running your elasticsearch integration tests with JUnit 5, Karate and TestContainers (Docker)

Earlier this year I wrote an article on how to run your integration tests with an embedded elasticsearch. When upgrading to elasticsearch 7 this method didn’t work (yet). An alternative (and maybe even better) method is using Testcontainers to run elasticsearch in a Docker container. I will also show how you can leverage Karate to do your integration testing.

How to remotely reload classes with Spring Developer Tools without opening extra ports

With Spring Developer Tools it is possible to reload classes on a local or remote machine from within your IDE without using JPDA. In this article I’ll show you how to do this and how to prevent this from happening on your production environment.

Writing integration tests for CORS headers (with Karate)

On many projects CORS headers are configured incorrectly. Usually by putting some wildcards (*) in the config and things ‘work’. In this article I will show how to create tests for the correct headers (using Karate, but it should be applicable to any test framework).

Running your JUnit 5 integration test with an embedded elasticsearch on a random port (and optionally Spring Boot)

With recent versions of elasticsearch (5+) the learning curve for an integration test became a bit steeper but will result in a cleaner solution in the end. In this article I will describe how to set up your test with JUnit 5 to run your elasticsearch integration tests. I will also discuss how to make it work with Spring-Boot Test.

Using ZAP-proxy and nginx to debug and tamper with HTTP traffic – Emulate timeouts and other unexpected behaviour

I recently ran into a problem where I was unable to set a proxy in an application. I wanted to use this proxy as a man-in-the-middle proxy to debug an external web service call. I solved this problem by using nginx to redirect the traffic to the proxy. Since 99 out of 100 articles about nginx proxies are about reverse proxies I decided to write about a forward proxy to save you some time and show you some of the features of a man-in-the-middle proxy.

Lessons learned after serving thousands of concurrent users in a devops team for a year

I just celebrated a year at a my customer. When I arrived the project was in a good shape with a few rough edges. There was a solid code review proces, a stable Jenkins server, motivated people, a reasonable amount of integration tests and a product owner who is very involved and very often in our vicinity. We serve thousands of users and our analist has the confidence to do a release at the busiest time of day.

Introduction to Java heap tuning – Some easy steps to improve response times

At our current project we wanted to upgrade our EC2 instance to a newer family and generation to improve response times and make our application start faster. This simple task started with blindly increasing the heap size and ended with counting strings on the heap.