Kubernetes pour des développeurs Java

Kubernetes for Java Developers Horacio Gonzalez @LostInBrittany

Who are we? Introducing myself and introducing OVH OVHcloud

Horacio Gonzalez @LostInBrittany Spaniard lost in Brittany, developer, dreamer and all-around geek Flutter

OVHcloud: A Global Leader 200k Private cloud VMs running 1 Dedicated IaaS Europe 30 Datacenters Own 20Tbps Hosting capacity : 1.3M Physical Servers 360k Servers already deployed Netwok with 35 PoPs

1.3M Customers in 138 Countries

OVHcloud: Our solutions Cloud Web Hosting Mobile Hosting Telecom VPS Containers ▪ Dedicated Server Domain names VoIP Public Cloud Compute ▪ Data Storage Email SMS/Fax Private Cloud ▪ Network and Database CDN Virtual desktop Serveur dédié Security Object Storage Web hosting Cloud Storage Over the Box ▪ Licences Cloud Desktop Securities MS Oﬃce Hybrid Cloud Messaging MS solutions

Orchestrating containers Like herding cats… but in hard mode!

From bare metal to containers Another paradigm shift

Containers are easy… For developers

Less simple if you must operate them Like in a production context

And what about microservices? Are you sure you want to operate them by hand?

Taming microservices with Kubernetes

Kubernetes is modular

Kubernetes Way more than a buzzword!

Masters and nodes

Some more details

Desired State Management

Multi-environment made easy Dev, staging, prod, multi-cloud…

Declarative infrastructure Multi-environment made easy

Having identical, software defined envs

I have deployed on Minikube, woah! A great fastlane into Kubernetes

Running a full K8s in your laptop A great learning tool

Your laptop isn’t a true cluster Don’t expect real performances

Beyond the first deployment So I have deployed my distributed architecture on K8s, everything is good now, isn’t it?

Minikube is only the beginning

GraalVM An alternative JVM with a twist

A long time ago, when the JVM was young HotSpot becomes the offical JVM in Java 1.3

HotSpot has tiered compilation It starts in interpreter mode, then C1 JIT and, if needed, C2 JIT

Really powerful, really complex Last big addition: JVM Intrinsics

It worked really well, but its getting old… C++ stack, old code base, difficult to maintain

The Java platform to the rescue JVM Compiler Interface (JVMCI) - JEP 243 Ahead of Time (AoT) Compilation - JEP 295

Graal project An Oracle project to rethink the JVM

Graal compiler ● A Java compiler written in Java ○ Capable of compiling itself! ● Independent of HotSpot ○ Can be used in HotSpot with JVMCI ● Can do either JIT or AOT compilations

What’s GraalVM? A standalone Java Development Kit to execute: ● JVM-based languages ● Dynamic languages ● LLVM-based languages

What’s GraalVM?

What’s GraalVM?

GraalVM Features GraalVM lets you: ● Run your code faster and more efficiently ● Interoperate directly with most modern programming languages ● Embed languages with the GraalVM SDK ● Create compiled native images ● Use a single set of tools to monitor, debug, and profile all your code

GraalVM base package The base installation includes: ● The JVM ● The Graal compiler ● The LLVM bitcode interpreter ● The JavaScript runtime

Why GraalVM? For Java programs: ● Run Java faster ● Make Your Application Extensible ● Create a Native Image

Why GraalVM? For JavaScript programs: ● Reuse Libraries from Java, R, or Python ● Run with Large Heaps ● Define Data Structures in C/C++

Why GraalVM? GraalVM native images reduce: ● Runtime memory footprint ● Startup time

And how does it compile ? Dead code elimination Closed world assumption

Adding some limitations…

Two versions Community Edition & Enterprise Edition

Polyglot GraalVM Wasm, JS, Ruby, Python, R, C, C++, Rust…

Sulong and Truffle Lots of languages… and growing!

Running JavaScript code function sayHello() { console.log(‘Hello!’); } sayHello(); Using GraalVM js command $ ~/opt/graalvm/bin/js sayHello.js Hello!

Running NodeJS code const http = require(“http”); const span = require(“ansispan”); require(“colors”); http.createServer(function (request, response) { response.writeHead(200, {“Content-Type”: “text/html”}); response.end(span(“Hello Graal.js!”.green)); }).listen(8000, function() { console.log(“Graal.js server running at http://127.0.0.1:8000/”.red); }); Using GraalVM node and npm commands $ ~/opt/graalvm/bin/npm install colors ansispan […] + colors@1.4.0 + ansispan@0.0.4 added 2 packages from 3 contributors in 14.951s $ ~/opt/graalvm/bin/node helloNode.js Graal.js server running at http://127.0.0.1:8000/

Running WebAssembly Programs #include <stdio.h> int main() { int number = 1; int rows = 10; for (int i = 1; i <= rows; i++) { for (int j = 1; j <= i; j++) { printf(“%d “, number); ++number; } printf(“.\n”); } return 0; } Using wasm launcher graalvm/bin/wasm —Builtins=memory,env:emscripten your_module.wasm

Embedding WebAssembly Programs import org.graalvm.polyglot.*; import org.graalvm.polyglot.io.ByteSequence; // You need to load the .wasm contents into a byte array. byte[] binary = readBytes(“example.wasm”); Source.Builder sourceBuilder = Source.newBuilder(“wasm”, ByteSequence.create(binary), “example”); Source source = sourceBuilder.build(); Context.Builder contextBuilder = Context.newBuilder(“wasm”); Context context = contextBuilder.build(); context.eval(source); Value mainFunction = context.getBindings(“wasm”).getMember(“_main”); mainFunction.execute();

GraalVM 💗 Kubernetes Giving Java a place in a Cloud Native world

Containers didn’t love Java Big images, slow to start, memory hungry…

GraalVM change things Small images, fast start, low memory footprint

Java is now a real alternative in Cloud Native First class cloud player!

But what about old apps? Most of them difficult to compile in GraalVM

Enter Quarkus A new generation Java app stack

Quarkus Supersonic Subatomic Java

What’s Quarkus? ● A Kubernetes Native Java stack ● Tailored for OpenJDK HotSpot and GraalVM ● Crafted from the best of breed Java libraries and standards

Container first

Unifies imperative and reactive Combine imperative code and the non-blocking reactive style

By developers, for developers ● Unified configuration ● Zero config, live reload in the blink of an eye ● Streamlined code for the 80% common usages, flexible for the 20% ● No hassle native executable generation

Leveraging the ecosystem Over fifty best-of-breed libraries wired on a standard backbone

Conclusion That’s all, folks!

Kubernetes for Java Developers Horacio Gonzalez @LostInBrittany