Richtige Integrationstests mit Containern Philipp Krenn @xeraa
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Developer
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Tests
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But the unit tests passed, so… https://twitter.com/Aaronius/status/ 933497253347463168
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Integration Tests
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Mocks
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Mockito, EasyMock, JMock,…
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Ich mock mir die Welt widdewidde wie sie mir gefällt
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https://www.monkeyuser.com/2018/ happy-flow/
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! Unit tests, systems not under your control ! Test real datastore
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In-Memory
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H2, HSQLDB, Apache Derby,…
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Embedded Elasticsearch unsupported in 5.0+ https://www.elastic.co/blog/elasticsearch-the-server
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! Often good enough ! Test real datastore, supported systems
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Actual Datastore
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Local installation Docker container Cloud
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Demo
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! “Good old approach” ! External dependency, parallelization
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Embedded
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embedded-elasticsearch https://github.com/allegro/embedded-elasticsearch
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Demo
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Customization & Mappings .withPlugin(“analysis-stempel”) .withIndex(“cars”, IndexSettings.builder() .withType(“_doc”, getSystemResourceAsStream(“car-mapping.json”))
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! IDE support, customization, custom lifecycle ! Custom integration
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More embedded datastores https://github.com/flapdoodle-oss/ de.flapdoodle.embed.process
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Build Tool
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docker-maven-plugin http://dmp.fabric8.io
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Dockerfile or Docker assembly <build> <from>java:8</from> <assembly> <descriptor>docker-assembly.xml</descriptor> </assembly> <cmd> <shell>java -jar /maven/service.jar</shell> </cmd> </build>
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Build a custom image: docker:build Run container: docker:start docker:stop
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Demo
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maven-failsafe-plugin https://maven.apache.org/surefire/maven-failsafe-plugin/
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! Standard or custom Docker image ! One instance for all tests, no IDE support
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Testcontainers Generic
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Dependency @ClassRule public static GenericContainer redis = new GenericContainer(“redis:5.0.5”) .withExposedPorts(6379);
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Docker Compose integration @ClassRule public static DockerComposeContainer environment = new DockerComposeContainer(new File(“src/test/resources/compose.yml”)) .withExposedService(“elasticsearch_1”, ELASTICSEARCH_PORT, Wait.forHttp(“/”).forStatusCode(200));
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Demo
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What’s in docker ps -a
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Docker for Mac API: socat Linux: Multipurpose relay (SOcket CAT) https://github.com/alpine-docker/socat
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Cleanup: Moby Ryuk https://github.com/testcontainers/moby-ryuk
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[Ryuk] drops a Death Note, a notebook that allows the user to kill anyone simply by knowing their name and face https://en.wikipedia.org/wiki/Ryuk_(Death_Note)
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! IDE support, customization, custom lifecycle ! Hacky configuration
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Testcontainers Custom
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ElasticsearchContainer https://www.testcontainers.org/modules/elasticsearch/
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Demo
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More languages Scala, Go, .net , Python , JavaScript , Rust * * * Early development * *
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Selenium 2 / Webdriver VNC screen recording
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! IDE support, customization, custom lifecycle ! Custom integration
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Inside Containers
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Wormhole Pattern
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$ docker run -it —rm -v $PWD:$PWD -w $PWD -v /var/run/docker.sock:/var/run/docker.sock maven:3 mvn —projects parent,4_testcontainers-custom test $ docker ps -a
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Conclusion
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Why Integration Tests
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Why not Mocking In-Memory Actual Datastore
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How Embedded Build Tool Testcontainers
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Code https://github.com/xeraa/integration-test-demo
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Questions? Philipp Krenn @xeraa
