Polyglot Adventures for the Modern Java Developer

#whoami
Mario-Leander Reimer
Chief Technologist, QAware GmbH
- Senior Developer && Architect
- 20+ years of experience
- #CloudNativeNerd
- Open Source Enthusiast
mario-leander.reimer@qaware.de
http://github.com/lreimer
http://speakerdeck.com/lreimer
// JavaOne 2017 // Everything-as-code -> { created with ❤ and ☕ by @LeanderReimer @qaware }

Which programming
language do real
developers use?

My #FirstSevenLanguages
• Pascal
• Basic
• C / C++
• Assembler
• PHP
• Java
• C#

My #LastSevenLanguages
• Java
• Groovy
• TypeScript
• Ruby
• Kotlin
• Scala
• Go

There is no unanimous opinion ...
• http://spectrum.ieee.org/computing/software/
the-2015-top-ten-programming-languages
• http://spectrum.ieee.org/computing/software/
the-2016-top-programming-languages
• http://redmonk.com/sogrady/2017/06/08/language-
rankings-6-17/

There is no best programming
language! Every language is
strong in a specific domain.

We are software craftsmen.
The IDE is our workbench.

Software Industrialization as
a key requirement for DevOps
and Continuous Delivery.

The software assembly line: produce
and deliver software continuously.

Definition of Software Industrialization
• Automation of repetitive and laborious tasks
• Better software quality through a standardized
and streamlined tool chain
• A well integrated tool chain leads to a higher
productivity and happiness of your team
• Better cost efficiency and competitiveness

val softwareIndustrialization = everythingAsCode()
open fun everythingAsCode() =
everythingIsMadeFromCode()
&& everythingIsMadeByCode()
private fun everythingIsMadeFromCode() = true
private fun everythingIsMadeByCode() = true

So our polyglot
adventures begin.

The Quest for an ideal project archetype
• Which languages are used for the specific
domains in our projects?
• Which tools are used for Setup, Build, Code,
Test, CI, Infrastructure, Documentation?
• What are the the dos and don'ts of using a
specific language or technology?
+ some Wishful Greenfield Thinking!

Lightweight Developer Provisioning
• [ SEU ] German acronym; Software Entwicklungs-Umgebung
• Use a build tool for the automated creation and update of a
software development environment
• Software packages are expressed as dependencies
• Gradle tasks and Groovy are used instead of shell scripting
• The SEU definition is version controlled just like ordinary
source code
• Available open source at http://seu-as-code.io

plugins { id 'de.qaware.seu.as.code.base' version '2.4.0' }
import static de.qaware.seu.as.code.plugins.base.Platform.isMac
seuAsCode {
seuHome = { if (isMac()) '/Volumes/Everything-as-code' else 'Y:' }
projectName = 'Everything-as-code'
}
dependencies {
// list of software dependencies ...
software 'org.groovy-lang:groovy:2.4.7'
software 'org.scala-lang:scala:2.11.8'
software 'org.jruby:jruby:9.1.4.0'
}

Maven is good. Gradle is 100x faster.
• Very flexible. Gradle can build everything.
• Polyglot builds are supported easily.
• Succinct build scripts. Default conventions over
configuration.
• Incremental builds, reduced build times.
• New features: Kotlin build scripts, Composite Builds,
Parallel Downloads, ...
• Frequent releases. Mature and stable.

apply plugin: 'application'
apply plugin: 'war'
apply plugin: 'kotlin'
apply plugin: 'groovy'
repositories { jcenter() }
dependencies {
providedCompile 'fish.payara.extras:payara-micro:4.1.1.164'
// and many more ...
}
task everythingAsCode() << {
println 'Everything-as-code using Gradle @ JavaOne 2017.'
}

There is nothing
wrong with Java as
primary language!

But Kotlin is a serious
alternative worth considering
as primary language.

But why Kotlin? And not Scala, Clojure, et.al.
• Easy to learn for Java developers.
• Well-balanced universal language.
• Inbuilt Null safety & Syntactic sugar &
Excellent interoperability.
• JDK6 compatible. Small library size.
• Good IDE and tool support.

@JsonIgnoreProperties(ignoreUnknown = true)
data class Book(val title: String, val isbn: String, val author: String)
@ApplicationScoped
open class Bookshelf {
private val books = listOf(Book("The Hitchhiker's Guide to the Galaxy", "0345391802"))
open fun byIsbn(isbn: String): Book? = books.find { it.isbn == isbn }
}
@Path("books")
@Produces(MediaType.APPLICATION_JSON)
open class BookResource @Inject constructor(private val bookshelf: Bookshelf) {
@GET @Path("/{isbn}")
open fun byIsbn(@PathParam("isbn") isbn: String): Response {
val book = bookshelf.byIsbn(isbn)
return if (book != null) Response.ok(book).build() else Response.status(Status.NOT_FOUND).build()
}
}
@ApplicationPath("api")
class BookstoreAPI : Application() {
override fun getClasses() = hashSetOf(JacksonFeature::class.java, BookResource::class.java)
}

Welcome to JavaScript wonderland.
• Clear trend towards Single Page Web Applications
• A strange universe on its own!
• Take a currently hip JavaScript UI framework.
• HTML5 + CSS3 + ?
• ? = TypeScript or
• ? = ECMAScript2015 + Babel
• Build Backbone: node + npm + webpack

Groovy and Spock for Unit & Integration Tests
class BookshelfSpec extends Specification {
@Subject
def bookshelf = new Bookshelf()
@Unroll
def "Find book #title by ISBN #isbn"() {
when: 'we search a book by ISBN'
def book = bookshelf.byIsbn(isbn)
then: 'the title and author are correct'
book?.title == title
book?.author == author
where:
isbn || title | author
"0345391802" || "The Hitchhiker's Guide to the Galaxy" | "Douglas Adams"
"0345391829" || "Life, the Universe and Everything" | "Douglas Adams"
}
}

Scala and Gatling for Load Testing
class BooksPerformanceTest extends Simulation {
val conf = http.baseURL("http://localhost:18080").acceptHeader("application/json")
val feeder = csv("books.csv").random
val scn = scenario("Book Search")
.exec(http("Get all books").get("/api/books"))
.during(30 seconds) {
feed(feeder)
.exec(http("Get book by title ${Title}").get("/api/books?title=${Title}"))
.pause(1 second)
.exec(http("Get book with ISBN ${ISBN}").get("/api/books/${ISBN}"))
}
setUp(scn.inject(atOnceUsers(10), rampUsers(50) over (30 seconds)))
.assertions(global.responseTime.max.lessThan(5000))
.protocols(conf)
}

Build Pipeline Definition via Jenkinsfile
#!/usr/bin/env groovy
node {
stage 'Checkout SCM'
checkout scm
stage 'Build/Analyse/Test'
sh './gradlew clean build'
archiveUnitTestResults()
archiveDistributions()
stage 'Dockerize'
sh './gradlew buildDockerImage'
stage 'Generate Documentation'
sh './gradlew asciidoctor'
}

Docker, Docker, Docker, ...
FROM qaware-oss-docker-registry.bintray.io/base/alpine-k8s-openjdk8:8u121
MAINTAINER M.-Leander Reimer <mario-leander.reimer@qaware.de>
RUN mkdir -p /app
ADD build/distributions/everything-as-code-1.2.1.tar /app
WORKDIR /app/everything-as-code-1.2.1
RUN chmod 755 bin/everything-as-code
EXPOSE 18080
CMD ./bin/everything-as-code

Vagrant and Ruby for local VM setup
require 'yaml'
$setup = <<SCRIPT
sudo apt-add-repository ppa:ansible/ansible
sudo apt-get update
sudo apt-get install -y ansible sshpass
SCRIPT
Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/trusty32"
settings = YAML.load_file 'src/vagrant/vagrant.yml'
config.vm.provider "virtualbox" do |vb|
vb.name = settings['vm']['name']
vb.gui = false
vb.memory = "512"
end
config.vm.provision "shell", inline: $setup
end

Provisioning with Ansible (and Python)
---
# file: jenkinsci.yml
- hosts: jenkinsci
remote_user: root
tasks:
- debug: msg="Creating a Jenkins pipeline job on {{ inventory_hostname }}"
- jenkins_job:
name: Everything-as-code Pipeline
config: "{{ lookup('file', 'templates/pipeline-job.xml') }}"
url: "http://{{ inventory_hostname }}"
user: admin
password: admin

Cluster Orchestration with Kubernetes
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: everything-as-code
spec:
replicas: 3
template:
metadata:
labels:
tier: backend
spec:
containers:
- name: everything-as-code
image: "qaware-oss-docker-registry.bintray.io/lreimer/everything-as-code:1.2.1"
ports:
- containerPort: 18080
env:
- name: PORT
value: 18080

Yes, we need documentation!
• And no, the source code is not enough.
• Writing technical docs with Word is ! " #
• Documentation should be located next to the
source code: change code, change docs.
• It should be easy, quick and fun to write.
• Support for code, images, UML diagrams, ...

// Beispiel Architektur-Dokumentation mit arc42 (https://arc42.github.io)
:imagesdir: ./images
= image:qaware-logo.png[QAware GmbH,2016] Everything-as-code
:toc-title: Table of Contents
:toc:
[[section-introduction-and-goals]]
== Introduction and Goals
The introduction to the architecture documentation should list the driving forces
that software architects must consider in their decisions.
=== Requirements Overview
=== Quality Goals
=== Stakeholders
<<<<
include::02_architecture_constraints.adoc[]
// further includes for the remaining sections

AsciidoctorJ and Gradle to the Rescue
plugins { id "org.asciidoctor.convert" version "1.5.3" }
asciidoctorj { version = '1.5.4.1' }
asciidoctor {
sourceDir 'src/docs/architecture'
resources {
from('src/docs/architecture') {
include 'images/**/*.png'
include 'images/**/*.jpg'
}
}
backends 'html5'
options doctype: 'article'
attributes 'source-highlighter': 'coderay'
}

Architecture documentation using Structurizr
def workspace = new Workspace("Everything-as-code", "The system context of Everything-as-code.")
def model = workspace.model
// create a model and the software system we want to describe
def bookApp = model.addSoftwareSystem("Book Application", "The best source to get info on books.")
// create the various types of people (roles) that use the software system
def anonymousUser = model.addPerson("Anonymous User", "Anybody on the web.")
anonymousUser.uses(bookApp, "Searches for books and views details.")
def browser = bookApp.addContainer("Web Browser",
"Allows users to view information about books", "Edge, Chrome, Firefox")
anonymousUser.uses(browser, "Views information from and makes requests to")
def webApp = bookApp.addContainer("Web Application",
"Hosts the browser-based web application and services", "Payara Fish")
browser.uses(webApp, "uses [JSON/HTTPS]")

Architecture validation using QAvalidator
architecture(name: "Mail Example", prefix: "tview", reflexMLversion: "1.0") {
excludes "java.lang.*"
api "JavaMail" : "javax.mail.*"
component "Mail" {
api "IMail" : "de.qaware.mail.*"
impl ["de.qaware.mail.impl.*", "de.qaware.mail.impl2.*"]
uses "JavaMail"
component "MailSender" {
api ["de.qaware.mail.sender.*", "javax.mail.*"]
impl "de.qaware.mail.impl.javamail.JavaMailSender"
uses "JavaMail"
}
}
}

These slides were written in Markdown.
---
## [fit] These slides were written in Markdown.
- This is for real programmers! :smiley:
- Several open source projects available
- Use HTML and JavaScript alternatively.
---

State of the art
software projects
are polyglot.

Use the right tool
for the job!

Use common sense!
The right language and tool depends on your
team, the project context and your customer.

Fork me on GitHub.
https://github.com/lreimer/everything-as-code

Please vote ! for
this session.

Polyglot Adventures for the Modern Java Developer

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