A presentation at Devoxx UK in in London, UK by Oleg Šelajev
Rethinking integration testing with Testcontainers
🛠 git IDE Docker (including Docker compose for some steps) Build tool: Maven / Gradle
➡ github.com/testcontainers/workshop docker pull postgres:14-alpine docker pull redis:6-alpine docker pull openjdk:8-jre-alpine fl docker pull con uentinc/cp-kafka:5.4.3
📖 https://bit.ly/devoxx-uk-2022-TC-lab
Agenda Intro & theory — 10 minutes Setup the project — 15 minutes Adding the rst tests — 10 minutes Your rst Testcontainers integration — 15 minutes Redis tests & Redis Generic container — 20 minutes Kafka tests — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Oleg Šelajev Developer relations Kevin Wittek Software engineer Piotr Przybył Software engineer / gardener
e2e Integration tests Unit tests By Unknown author - U.S. Army Photo, Public Domain, https://commons.wikimedia.org/w/index.php?curid=55124
Microservices Testing Honeycomb https://labs.spotify.com/2018/01/11/testing-of-microservices/
https://martinfowler.com/bliki/IntegrationTest.html
• Process isolation • FileSystem, Network • CPU/memory limits
• Con guring multiple services simultaneously • Flexibility in creating test data or use-cases • Separation of production & test environments • Dynamic con guration of external mappings • Parallel deployments fi fi 😅
testcontainers.org
System checks Checking the system… ✔ Docker version should be at least 1.6.0 ✔ Docker environment should have more than 2GB free disk space ✔ File should be mountable ℹ︎ ✔ A port exposed by a docker container should be accessible
During After
The problem Extra mile Port conflicts Port randomization Hard-coded scenarios Data-driven tests Slow tests Parallelization
We think it’s a useful default option for creating a reliable environment for running tests. … Our teams have consistently found this library of programmable, lightweight and disposable containers to make functional tests more reliable. https://www.thoughtworks.com/en-us/radar/languages-and-frameworks/testcontainers
Downloads
Unique IPs
What to do if you have no Docker?
Docker environments https://www.atomicjar.com/2021/10/docker-on-windows-and-macos
Testcontainers Cloud testcontainers.cloud
Model: record Rating (String talkId, Integer value) {}
Resources — github.com/testcontainers/testcontainers-java — www.testcontainers.org
Let’s get started ! — github.com/testcontainers/workshop
Agenda Intro & theory — ✅ Setup the project: Steps 1 & 2 — 15 minutes Adding the rst tests — 10 minutes Your rst Testcontainers integration — 15 minutes Redis tests & Redis Generic container — 20 minutes Kafka tests — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min github.com/ testcontainers/ workshop
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests: Step 3 — 10 minutes Your rst Testcontainers integration — 15 minutes Redis tests & Redis Generic container — 20 minutes Kafka tests — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration: Step 4 — 15 minutes Redis tests & Redis Generic container — 20 minutes Kafka tests — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container: Steps 5 & 6 — 20 minutes Kafka tests — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container — ✅ Kafka tests: Step 7 — 15 minutes Testcontainers without the framework support — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container — ✅ Kafka tests — ✅ Testcontainers without the framework support: Step 8 — 20 min Database initialization setup — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container — ✅ Kafka tests — ✅ Testcontainers without the framework support — ✅ Database initialization setup: Step 9 — 20 min fi fi Migrating Docker-compose to Testcontainers — 20 min
Agenda Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container — ✅ Kafka tests — ✅ Testcontainers without the framework support — ✅ Database initialization setup — ✅ fi fi Migrating Docker-compose to Testcontainers: Step 10 — 20 min
Congrats! Intro & theory — ✅ Setup the project — ✅ Adding the rst tests — ✅ Your rst Testcontainers integration — ✅ Redis tests & Redis Generic container — ✅ Kafka tests — ✅ Testcontainers without the framework support — ✅ Database initialization setup — ✅ fi fi Migrating Docker-compose to Testcontainers — ✅
Before Docker, configuring the environment for integration testing was painful – people were using fake database implementations, mocking servers, usually it was not cross-platform as well. However, thanks to Docker, now we can quickly prepare the environment for our tests.
In this lab, I would like to show how you can use Testcontainers – a popular testing library that harnesses Docker to easily, reliably, spin up test dependencies.
You’ll go through the process adding powerful integration tests to your codebase (we’ll use a Spring Boot app) without the headache of managing external service dependencies manually. And get acquainted with all necessary Testcontainers concepts to write elegant, efficient, and reliable integration tests.
The following resources were mentioned during the presentation or are useful additional information.
for free. You
can too.