Options Galore: From Source Code to Container Image

A typical workflow in a modern software dev project can look like: Build code, put built artifact into container image, put container image into registry, deploy to Kubernetes. Each step has it’s own requirements and pitfalls alike. The overall goal is most often to bake those steps into easily repeatable pipelines and enable a high degree of automation.

Dockerfiles seems to be the choice with the highest adoption when it comes to containerizing code artifacts. However there are options, which might remove some of the pitfalls and standardize the entire process even more.

The talk will give deeper insights by comparing (multi-stage) Dockerfiles to Cloud-Native Buildpacks (buildpacks.io/paketo.io) and Google’s JIB under the evaluation criteria of build time, build size, standardization, robustness and security. The examples and live demo will have certain focus on Java-based frameworks (Spring Boot, Quarkus, Java EE), but coverage of other languages will also be included and highlighted.

The intented take-away of the session is a better overview of container building and deployment options along with understanding of requirements, advantages and drawbacks.

Transcript

1. Dockerfiles, Buildpacks, Jib and more ... what's the best way to run your Java code in Containers? Matthias Haeussler, Chief Technologist @maeddes
3. @maeddes | 3 What we really do
4. @maeddes | 4 What we really do
5. @maeddes | 5 What we really do
6. @maeddes | 6 What we really do
7. @maeddes | What I do/ What we do 7
8. @maeddes | Situation 8
9. @maeddes | Options 9
10. @maeddes | Options 10
11. @maeddes | Situation 11
12. @maeddes | Lab Repo 12
13. @maeddes | „What is the best Java base container image?“ 13
14. @maeddes | 14
15. @maeddes | 15
16. @maeddes | „What is the best Java base container image?“ 16
17. @maeddes | Container Images as Templates 17
18. @maeddes | Container, Images & Layers 18
19. @maeddes | Docker History 19 [1]
20. @maeddes | 20 FROM ubuntu:24.04 RUN apt update && apt install openjdk-21-jre-headless -y COPY target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar CMD ["java","-jar","/opt/app.jar"] Dockerfile (simple)
21. @maeddes | Java today 21
22. @maeddes | Alternative Dockerfile 22 FROM eclipse-temurin:21-jre COPY target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar CMD ["java", "-jar", "/opt/app.jar"]
23. @maeddes | Alternative Dockerfile 23 FROM ibm-semeru-runtimes:open-21-jre COPY target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar CMD ["java", "-jar", "/opt/app.jar"]
24. @maeddes | JVM Landscape Talk - Gerrit Grunwald 24 https://www.youtube.com/watch?v=9_9L3pqGFcQ
25. @maeddes | Beware! 25
26. @maeddes | Be careful - This will still “work”! 26 FROM adoptopenjdk:11-jre-hotspot COPY target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar CMD ["java", "-jar", "/opt/app.jar"]
27. @maeddes | Multi-Stage 27 [1]
28. @maeddes | Multi-Stage Dockerfile 28 FROM maven:3-eclipse-temurin-21 AS build RUN mkdir -p /opt/app/src COPY src /opt/app/src COPY pom.xml /opt/app RUN mvn -f /opt/app/pom.xml package FROM eclipse-temurin:21-jre COPY --from=build /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar ENTRYPOINT ["java","-jar","/opt/app.jar"]
29. @maeddes | Multi-Stage Dockerfile 29 FROM maven:3-eclipse-temurin-21 AS build RUN mkdir -p /opt/app/src COPY src /opt/app/src COPY pom.xml /opt/app RUN mvn -f /opt/app/pom.xml package FROM eclipse-temurin:21-jre COPY --from=build /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar ENTRYPOINT ["java","-jar","/opt/app.jar"]
30. @maeddes | Multi-Stage Dockerfile 30 FROM maven:3-eclipse-temurin-21 AS build RUN mkdir -p /opt/app/src COPY src /opt/app/src COPY pom.xml /opt/app RUN mvn -f /opt/app/pom.xml package FROM eclipse-temurin:21-jre COPY --from=build /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar ENTRYPOINT ["java","-jar","/opt/app.jar"]
31. @maeddes | Buildkit 31 [1]
32. @maeddes | 32
33. @maeddes | 33
34. @maeddes | Mount Cache 34 FROM maven:3-eclipse-temurin-21 AS build RUN mkdir -p /opt/app/src COPY src /opt/app/src COPY pom.xml /opt/app RUN --mount=type=cache,target=/root/.m2 mvn -f /opt/app/pom.xml package FROM eclipse-temurin:21-jre COPY --from=build /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar /opt/app.jar ENTRYPOINT ["java","-jar","/opt/app.jar"]
35. @maeddes | „What makes a (Java) container image good?“ 35
36. @maeddes | • Speed • Size • Structure • Standardization • Simplicity • Security Criteria 36
37. @maeddes | • Speed • Size • Structure • Standardization • Simplicity • Security • JVM configuration Criteria 37
38. @maeddes | The reality … 38
39. @maeddes | Considerations for structure and size 39
40. @maeddes | Considerations for Java 40
41. @maeddes | Layered Jar 41 FROM eclipse-temurin:21-jre AS builder COPY --from=maven /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar application.jar RUN java -Djarmode=layertools -jar application.jar extract FROM eclipse-temurin:21-jre COPY --from=builder application/dependencies/ ./ COPY --from=builder application/spring-boot-loader/ ./ COPY --from=builder application/snapshot-dependencies/ ./ COPY --from=builder application/application/ ./ ENTRYPOINT ["java","org.springframework.boot.loader.JarLauncher"]
42. @maeddes | Entire file 42 FROM maven:3-eclipse-temurin-21 AS maven RUN mkdir -p /opt/app/src COPY src /opt/app/src COPY pom.xml /opt/app RUN --mount=type=cache,target=/root/.m2 mvn -f /opt/app/pom.xml package FROM eclipse-temurin:21-jre AS builder WORKDIR application COPY --from=maven /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar application.jar RUN java -Djarmode=layertools -jar application.jar extract FROM eclipse-temurin:21-jre WORKDIR application COPY --from=builder application/dependencies/ ./ COPY --from=builder application/spring-boot-loader/ ./ COPY --from=builder application/snapshot-dependencies/ ./ COPY --from=builder application/application/ ./ ENTRYPOINT ["java","-XX:+UseParallelGC","-XX:MaxRAMPercentage=75","org.springframework.boot.loader.JarLauncher"]
43. @maeddes | Dockerfile and jlink (and jdeps) 43 https://snyk.io/blog/jlink-create-docker-images-spring-boot-java/
45. @maeddes | jlink and jdeps 45 FROM maven:3-eclipse-temurin-21 AS build RUN --mount=type=cache,target=/root/.m2 mvn package RUN jdeps --ignore-missing-deps -q \ --recursive \ --multi-release 21 \ --print-module-deps \ --class-path 'BOOT-INF/lib/*' \ target/simplecode-0.0.1-SNAPSHOT.jar > deps.info RUN jlink \ --add-modules $(cat deps.info) \ --strip-debug \ --compress 2 \ --no-header-files \ --no-man-pages \ --output /myjre FROM debian:bookworm-slim COPY --from=build /myjre $JAVA_HOME COPY --from=build /usr/src/project/target/simplecode-0.0.1-SNAPSHOT.jar /project/
46. 46 FROM maven:3-eclipse-temurin-21 AS build RUN mkdir /opt/app COPY src /opt/app/src COPY pom.xml /opt/app WORKDIR /opt/app RUN --mount=type=cache,target=/root/.m2 mvn package -DskipTests RUN jar xf target/simplecode-0.0.1-SNAPSHOT.jar RUN jdeps --ignore-missing-deps -q \ --recursive \ --multi-release 21 \ --print-module-deps \ --class-path 'BOOT-INF/lib/*' \ target/simplecode-0.0.1-SNAPSHOT.jar > deps.info RUN jlink \ --add-modules $(cat deps.info) \ --strip-debug \ --compress 2 \ --no-header-files \ --no-man-pages \ --output /myjre FROM eclipse-temurin:21-jre AS extractor RUN mkdir /opt/app WORKDIR /opt/app COPY --from=build /opt/app/target/simplecode-0.0.1-SNAPSHOT.jar application.jar RUN java -Djarmode=layertools -jar application.jar extract FROM ubuntu:jammy ENV JAVA_HOME /opt/java/jdk21 ENV PATH $JAVA_HOME/bin:$PATH COPY --from=build /myjre $JAVA_HOME RUN mkdir /opt/app WORKDIR /opt/app COPY --from=extractor /opt/app/dependencies/ ./ COPY --from=extractor /opt/app/spring-boot-loader/ ./ COPY --from=extractor /opt/app/snapshot-dependencies/ ./ COPY --from=extractor /opt/app/application/ ./ ENTRYPOINT ["java","-XX:+UseParallelGC","-XX:MaxRAMPercentage=75","org.springframework.boot.loader.JarLauncher"]
47. @maeddes | 47 Dockerfile Learnings
48. 48 & more …?
49. @maeddes | 49 [2]
50. @maeddes | 50 [2]
52. @maeddes | Jib 52
53. @maeddes | Jib 53
54. @maeddes | Jib 54
55. @maeddes | Considerations - Recap 55
56. @maeddes | Continued strategy 56
57. @maeddes | Jib 57
58. 58 Cloud-Native Buildpacks buildpacks.io
59. @maeddes | Buildpacks idea 59
60. @maeddes | History 60
61. @maeddes | Flow 61
62. @maeddes | Rebase 62
63. 63 paketo.io
64. @maeddes | Multi Runtime/Language Support 64 [3]
65. @maeddes | Rebase 65
66. @maeddes | 66 Flow
67. @maeddes | Java settings 67
68. @maeddes | 68
69. @maeddes | Summary 69 • Be aware of options and possibilities • Be aware of the possibilities of your options • Keep your base images and layers as consistent as possible throughout your landscape • Avoid “wild growth” through dockerfiles • Automate and standardize as much as possible • Give jib and buildpacks a try
70. @maeddes | 70 Dockerfile (simple) Dockerfile (multistage) Dockerfile (jlink/jdeps) Jib Buildpacks/ Paketo Speed 🤩 Size 🤩 Structure 🙂 🙂 🤩 🤩 Standardization 🙂 🙂 🙂 🤩 Simplicity 🙂 🤩 🙂 Security 🙂 🤩 🙂
71. @maeddes | Lab Repo 71
72. Novatec Consulting GmbH Bertha-Benz-Platz 1 D-70771 Leinfelden-Echterdingen T. +49 711 22040-700 info@novatec-gmbh.de www.novatec-gmbh.de 72 Chief Technologist Matthias Haeussler Mobil: +49 175 222 5949 E-Mail: matthias.haeussler@novatec-gmbh.de Twitter: @maeddes
73. Sources @maeddes | ▪ https://www.excalidraw.com ▪ [1] https://docs.docker.com/engine/release-notes/prior-releases/ ▪ [2] https://blog.codecentric.de/en/2020/11/buildpacks-spring-boot/ ▪ [3] https://paketo.io/ ▪ https://buildpacks.io/features/ ▪ https://github.com/GoogleContainerTools/jib ▪ https://www.baeldung.com/docker-layers-spring-boot ▪ https://spring.io/blog/2020/01/27/creating-docker-images-with- spring-boot-2-3-0-m1 ▪ https://github.com/openshift/source-to-image 73