A presentation at Spring IO 2022 in in Barcelona, Spain by Oleg Šelajev
Testcontainers and SpringBoot: from integration tests to local development
Things we love
Top things engineers wish they could spend less time on https://retool.com/reports/state-of-engineering-time-2022/
e2e Integration tests Unit tests By Unknown author - U.S. Army Photo, Public Domain, https://commons.wikimedia.org/w/index.php?curid=55124
https://labs.spotify.com/2018/01/11/testing-of-microservices/
Oleg Šelajev Developer relations @shelajev github.com/shelajev oleg@atomicjar.com
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 😅
—version: ‘2’ services: zookeeper: image: con uentinc/cp-zookeeper:7.0.1 ports: - “32181:32181” environment: ZOOKEEPER_CLIENT_PORT: 32181 ZOOKEEPER_TICK_TIME: 2000 kafka: image: con uentinc/cp-kafka:7.0.1 ports: - “29092:29092” depends_on: - zookeeper environment: KAFKA_BROKER_ID: 1 KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181 KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:29092 fl fl KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR :1
testcontainers.org
Testcontainers-java • Created 7 years ago • github.com/testcontainers/testcontainers-java • Uses docker-java API • Integrates with frameworks, like Spring, JUnit • Automatic Docker environment discovery • Automatic cleanup
Replacing a hard problem with a hard solution is not success. Nor is replacing an easy problem with an easy solution.
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
Show me the code
Model: record Rating (String talkId, Integer value) {}
https://github.com/spring-projects/spring-boot/issues/29461
What’s next? Reusable containers Networks for more complex topologies Custom startup & waiting strategies Creating images on-the- y fl fi Logs, les, commands, limits…
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
What’s next? — www.testcontainers.org — github.com/testcontainers/testcontainers-java ! — github.com/testcontainers/workshop
Thanks!
Testcontainers libraries integrate with Spring Boot to offer seamless, unit-test like experience for integration tests with real services running in containers: Kafka, databases, Elasticsearch, cloud technologies and everything else runnable in Docker. This flexibility can help in development environments automatically providing access to all required services without complex setups.
In this session we’ll show how you can supercharge your existing testing infrastructure based on Testcontainers for local development, programmatically require service dependencies without sacrificing speed of your development loop!
for free. You
can too.