Spring Playground

Purpose

Having a project, always ready, as starting point for a Spring (Boot) Application or just a playground to try something Spring Framework related.

Features

• Configure DispatcherServlet for loadOnStartup: do not delay first request with initialization.
• Custom ErrorController (sample.service.error.CustomErrorHandler): replace whitelabel error page.
• Custom ErrorAdvice (sample.service.error.CustomErrorAdvice): handle your exception as you need.
• RestController Integration Test (ApplicationIntegrationTest) example.
• Spring bootBuildImage example with explanation how to add custom CA(s).
• Spring Kafka Reset Offset on-demand (activate with spring.profiles.active=kafka)

bootBuildImage

./gradlew bootBuildImage

Custom CA(s) at Runtime

Add your CA(s) as PEM to bindings/ca-certificates.

Run the containern with --env SERVICE_BINDING_ROOT=/bindings --volume "$(pwd)/bindings/ca-certificates:/bindings/ca-certificates"

docker container run --rm --name spring-playground --env SERVICE_BINDING_ROOT=/bindings --volume "$(pwd)/bindings/ca-certificates:/bindings/ca-certificates" -p 8080:8080 docker.io/library/spring-playground:1.0.0  

In output - at the very beginning - sth. like

Added 1 additional CA certificate(s) to system truststore

should be seen, now get into container:

docker container exec -ti spring-playground bash

you can check truststore content:

/layers/paketo-buildpacks_bellsoft-liberica/jre/bin/keytool -list -cacerts
# Passwort: changeit

You will find one which has an alias starting with /tmp/ca-certificates.... which is yours.

cnb@54a0707470ca:/$ /layers/paketo-buildpacks_bellsoft-liberica/jre/bin/keytool -list -cacerts -alias /tmp/ca-certificates1242952937/954ac54b.0-0
Enter keystore password:
/tmp/ca-certificates979321829/954ac54b.0-0, Jan 1, 1980, trustedCertEntry,
Certificate fingerprint (SHA-256): CA:DB:CB:FC:DA:10:FB:36:7D:1F:7F:9D:7C:BF:EF:E7:16:AB:CC:20:9C:B5:B4:DE:62:7E:12:92:50:EF:E6:4E

Notes

• http://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html
• https://paketo.io/docs/buildpacks/language-family-buildpacks/java/

Happy coding!