This document discusses Spring on Kubernetes and containerization best practices. It provides an overview of Spring Boot 2.2 updates, how to build container images following best practices, memory configuration for containers, using testcontainers for testing, and an introduction to Spring Cloud Kubernetes for building portable apps on Kubernetes.

1. © Copyright 2019 Pivotal Software, Inc. All rights Reserved.
Jay Lee(jaylee@pivotal.io)
Advisory Platform Architect
Spring on PKS(Kubernetes)

2. Cover w/ Image
Agenda
■ Spring Update
■ How to Build Container Image?
■ Memory Configuration
■ testcontainer
■ Spring Cloud Kubernetes

3. Spring Update

4. Spring Boot 2.2
• Based on Spring Framework 5.2
• Spring Boot 1.x is end-of-life as of August 1st
• Java 13 Support added
• RSocket support
• 20~40% latency improvement over Sprinng Boot 2.1

5. Spring Boot 2.2 and Container
• Cloud Platform Kubernetes detection
import org.springframework.boot.autoconfigure.condition.ConditionalOnCloudPlatform;
import org.springframework.boot.cloud.CloudPlatform;
import org.springframework.stereotype.Service;
@Service
@ConditionalOnCloudPlatform(CloudPlatform.KUBERNETES)
public class K8sService {
}

6. Startup Time

7. How to Build Container Image

8. “Writing a quality Dockerfile is
still my users’ biggest point of friction”
David Dollar, CEO, Convox (a k8s/Docker PaaS)

9. Best practices for building containers
• Package a single app per container
• Properly handle PID 1, signal handling, and zombie processes
• Optimize for the Docker build cache
• Remove unnecessary tools
• Build the smallest image possible
• Use vulnerability scanning in Container Registry
• Properly tag your images
• Carefully consider whether to use a public image
From: https://cloud.google.com/solutions/best-practices-for-building-containers

10. Best practices for building containers
• Package a single app per container
• Properly handle PID 1, signal handling, and zombie processes
• Optimize for the Docker build cache
• Remove unnecessary tools
• Build the smallest image possible
• Use vulnerability scanning in Container Registry
• Properly tag your images
• Carefully consider whether to use a public image
From: https://cloud.google.com/solutions/best-practices-for-building-containers

17. Cloud Native Buildpack

24. kpack
Builder
BuildImage
Source
Resolver
SecretSecret
Git
Repository
Container
Registry
repository
Kubernetes resource
kpack resource
Buildpack
image
application
source code
built container image
Pod
Build
Build
Build
Build
Service
Account

25. kpack
container registry
Controllers
riff
riff: core and streaming
$ riff function create...
Function
Application
build.projectriff.io
Deployer
Stream
Processor
core.projectriff.io
streaming.projectriff.io
CRDs
SourceResolver
Builder
Build
Image
Deployment
ReplicaSet
Pod
Service
Kubernetes
CRDs
$ riff core deployer create...
$ riff streaming processor create...

26. Startup Time

27. Memory Configuration

28. Java Improvements for Docker Containers
• -XX:+UseContainerSupport added and backported to JDK
8u191 -
https://www.oracle.com/technetwork/java/javase/8u191-
relnotes-5032181.html
• -XX:ActiveProcessorCount

29. Cloud Foundry Java Buildpack
• java-buildpack-memory-calculator
• -Xmx404417K
• -Xss1M
• -XX:ReservedCodeCacheSize=240M
• -XX:MaxDirectMemorySize=10M
• -XX:MaxMetaspaceSize=132158K

30. testcontainer

32. testcontainer
• Java library that supports JUnit tests, providing lightweight, throwaway instances of
common databases, Selenium web browsers, or anything else that can run in a
Docker container.
• Data access layer integration tests
• Application integration tests
• UI/Acceptance tests

33. What is Spring Cloud
Kubernetes?

34. Why Spring Cloud Kubernetes?
Write Portable apps using Spring Cloud
• Same source code for different environments
• Spring Cloud provides right platform abstraction on no
matter which environments you use
• Seamless integration between Kubernetes and Spring
• Spring Cloud Kubernetes is GA since Feb 2019

35. Spring Cloud nicely fits with Kubernetes
Native Service Discovery
● Leverage Spring Cloud
Netflix without using
Eureka discovery server
● DiscoveryClient uses
Kubernetes DNS resolver
and cluster events
● Use @LoadBalanced and
LoadBalancerClient for
client-side load balancing
● Spring Cloud
Circuitbreaker
support(Hystrix and
Resilience4j)
Pod Health Indicator
● Pod health indicator
contributes to Health
actuator(/actuator/health)
Kubernetes Aware
● When app is running in
Kubernetes, profile
kubernetes is
automatically enabled
ConfigMap/Secret Support
● Hot reload configuration
● Inject External
configuration properties
using ConfigMap
● Map Spring config support
with ConfigMap: @Value,
@ConfigurationProperties
● Load Secret values into
beans

36. Transforming How The World Builds Software
© Copyright 2019 Pivotal Software, Inc. All rights Reserved.