Gradle is a build automation tool that uses Groovy as its configuration language. It aims to provide a flexible, customizable, and extensible build system that understands Ant and Maven builds. Gradle builds upon the concepts of Ant and Maven but aims to provide a more flexible and customizable build system. It supports various programming languages and frameworks out of the box and has plugins for additional functionality. Gradle builds are defined using Groovy build scripts and it supports various IDEs and continuous integration servers.

1. Corneil du Plessis
Gradle: The Build system you have been waiting for!
DevOps &
Automation

2. Gradle: Introduction

Scope

History Lesson
− Make
− Ant
− Maven

Gradle
− What is it?
− Is Groovy
− Artefacts
− Builtin Support
− Case studies

3. Gradle: Make

Targets, dependencies, rules

Sample:
CFLAGS ?= -g
all: helloworld
helloworld: helloworld.o
# Commands start with TAB not spaces
$(CC) $(LDFLAGS) -o $@ $^
helloworld.o: helloworld.c
$(CC) $(CFLAGS) -c -o $@ $<

Suffix rules:
.c.o:
$(CC) $(CFLAGS) -c $<

4. Gradle: Ant

Projects, targets, dependency, built-in tasks, taskdef.
<project name="SampleWebApp" default="all" basedir=".">
<property name="app.name" value="SampleWebApp"/>
<property name="lib.dir" value="${basedir}/lib"/>
<property name="work.dir" value="${basedir}/work"/>
<property name="dist.dir" value="${basedir}/dist"/>
<property name="src.dir" value="${basedir}/src"/>
<property name="web.dir" value="${basedir}/web"/>
<path id="compile.classpath">
<fileset dir="${lib.dir}">
<include name="*.jar"/>
</fileset>
</path>

5. Gradle: Ant – cont.
<target name="all" depends="clean,compile,dist" description="Clean dirs,compile,create a WAR"/>
<target name="clean" description="Delete old work and dist directories">
<delete dir="${work.dir}"/>
<delete dir="${dist.dir}"/>
</target>
<target name="prepare" depends="clean" description="Create work dirs copy static files to work dir">
<mkdir dir="${dist.dir}"/>
<mkdir dir="${work.dir}/WEB-INF/classes"/>
<copy todir="${work.dir}">
<fileset dir="${web.dir}"/>
</copy>
</target>
<target name="compile" depends="prepare" description="Compile sources and copy to WEB-INF/classes dir">
<javac srcdir="${src.dir}" destdir="${work.dir}/WEB-INF/classes">
<classpath refid="compile.classpath"/>
</javac>
<copy todir="${work.dir}/WEB-INF/classes">
<fileset dir="${src.dir}" excludes="**/*.java"/>
</copy>
</target>
<target name="dist" depends="compile" description="Create WAR file for binary distribution">
<jar jarfile="${dist.dir}/${app.name}.war" basedir="${work.dir}"/>
</target>
</project>

6. Gradle: Maven

POM, Goals, Lifecycle, Plugins, Profiles

Maven Repository
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>io.jumpco.samples</groupId>
<artifactId>SampleWebApp</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>SampleWebApp Maven Web App</name>
<url>http://maven.apache.org</url>
<properties>
<spring.version>4.2.4.RELEASE</spring.version>
<junit.version>4.12</junit.version>
<jdk.version>1.8</jdk.version>
</properties>

7. Gradle: Maven – cont
<dependencies>
<!-- Spring 3 dependencies →
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>

8. Gradle: Maven – cont
<build>
<finalName>SampleWebApp</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

9. Gradle: What is it?

Gradle is a Groovy DSL for creating build scripts

Gradle has a beautiful designed model for Tasks,
Dependencies, Conventions etc.

Gradle understands Ivy and Maven repositories

Gradle can execute Ant scripts and tasks directly

This is a valid Gradle build script:
apply plugin: 'war'

10. Gradle: What does it look like?
build.gradle
apply plugin: 'java'
apply plugin: 'war'
repositories {
mavenCentral()
}
group = 'io.jumpco.samples'
version = '1.0-SNAPSHOT'
sourceCompatibility = 1.8
dependencies {
compile “org.springframework:spring-core:$springVersion”
compile “org.springframework:spring-web:$springVersion”
compile “org.springframework:spring-webmvc:$springVersion”
testCompile group: 'junit', name: 'junit', version: junitVersion
}
settings.gradle
rootProject.name = 'SampleWebApp'
gradle.properties
springVersion=4.2.4.RELEASE
junitVersion=4.11

11. Gradle: Is Groovy

DSL Handlers

Closures
repositories {
maven {
url 'http://download.java.net/mave/2/'
}
}

Strings
'org.springframework:spring-core:' + springVersion
“org.springframework:spring-core:$springVersion”

12. Gradle: Artifacts
● build.gradle
– buildScript
– configurations
– dependencies
– apply plugin
– artifacts
– sourceSets
– other dsl sections and Groovy
● settings.gradle
– subprojects
● gradle.properties
– Global properties
● buildSrc
– Custom tasks

13. Gradle: Builtin Support

Ant Projects, Tasks

Java, Jar, War, Ear

Scala, Groovy, GNU Compilers, Clang, Visual C++

Build Reporting

ANTLR

OSGi

Sonar, Pmd, Jacoco, CheckStyle, FindBugs, CodeNarc,
JDepend

Maven Publish, Ivy Publish, Signing, Distribution

Jetty

Announcements (Twitter, Growl, Snarl, notify-send)

14. Gradle: IDE Support
● Eclipse
● IntelliJ
● Netbeans
● Use your imagination

15. Gradle: Create scripts

gradle init –type basic|pom|java-library

Create build.gradle and other files
− Basic, Java Library, Scala Library, Groovy Library
− Choose test framework
− Convert pom
●
IDE New Gradle Project
●
Checkout lazybones at
https://github.com/pledbrook/lazybones

16. Gradle: Wrapper
gradle wrapper
Creates gradlew, gradlew.bat, gradle folder. Small enough to
checkin.
./gradlew build
Downloads Gradle version and executes build task.

17. Gradle: Other

Gradle UI – Swing application

Gradle Daemon will remain running and will reload only
modified scripts to improve execution time.

--continuous option. Gradle will remain running and trigger
build when input artefacts modified.

New Build Model

18. Gradle: 3rd
Party plugins

http://plugins.gradle.org

Google Android Development

Bintray publishing.

Artifactory

Spring IO Framework

https://github.com/nebula-plugins

Google App Engine

Tomcat

lessCss, minCss, minJs

19. Gradle: Cases Studies
● 2000 components, 1000 release builds per day
● Nebula. Patched Gradle.
● Enterprise Projects with > 300 modules
● Partial Local build.
● Generate documentation
● Deployment automation

20. Gradle: Summary
● Made for Customisation
● Robust Dependency Management
● Build Reporting
● The same flexible Build Model for both continuous
integration and local development.
● One source of the truth

21. /* THANK YOU*/
Corneil du Plessis
JumpCo (formerly TSC Technologies)
corneil@jumpco.io
corneil.duplessis@gmail.com
https://about.me/corneil
Demo project:
https://github.com/corneil/gradle-docs
http://www.devconf.co.za/Rate