Gradle beyond Android. Or going crazy with build automation

Nowadays almost all Android projects are built with Gradle but do you know that Gradle is not only for Android? You can go pretty crazy with it's possibilities.

During the talk, Vitaliy will share his experience with adopting Gradle to manage complex GetSocial SDK build process with Android, iOS and Unity 3D subprojects.

As a bonus, he'll run quick walk through Gradle plugin creation process and tell how you can share it with the world.

Transcript

1. Gradle beyond Android
   Or going crazy with build automation
   Vitaliy Zasadnyy
   Head of Mobile @ GetSocial
   Founder @ GDG Lviv
   

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2. #devfestnl
   Gradle is a first class build
   automation citizen on Android
   This presentation is about Gradle
   out of the scope of Android
   

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3. At GetSocial we make SDK to add
   social features to your app/game
   

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4. GetSocial SDK is available on three
   major platforms
   

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5. #devfestnl
   GetSocial SDK architecture
   Android
   SDK
   iOS
   SDK
   iOS Bridge Android Bridge
   C# API
   Unity SDK
   Java Objective C C#
   Public interfaces are
   exposed on: Android -
   Java, iOS - ObjectiveC,
   Unity - C#
   Unity SDK forwards calls
   to native SDKs via thin
   bridge layer
   

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6. #devfestnl
   Tasks to automate
   Build test apps
   Run Unit Tests
   Run Integration Tests
   Build Android SDK
   Build iOS SDK
   Build Unity SDK
   Generate Docs
   Deploy to Hokeyapp
   

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7. #devfestnl
   Prehistory of build automation at GetSocial
   • Android: Gradle + Eclipse
   • iOS: Xcode shell build scripts
   • Unity: bash scripts
   When I joined GetSocial automation
   was set up properly on Android and
   iOS
   On Unity - it was written long time
   ago => outdated and not working
   Main problem: 3 platforms - 3
   different approaches to automation
   

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8. #devfestnl
   Requirements for new build pipeline
   • Unified
   • Crossplatform
   • Concise, clear and pragmatic
   • Powerful
   Unified: one tool for all platforms
   Crossplatform: work on Windows
   and OSX
   No way for XML or similar
   Powerful: it should be easy to
   extend automation logic
   

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9. #devfestnl
   Available options
   Ant? No, just kidding :)
   

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10. #devfestnl
    Available options
    Bash pros: applicable to all our
    platforms; with Cygwin runs on
    Windows; pragmatic but not object
    oriented; powerful enough
    Bash cons: on Windows kind of
    magic, no
    

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11. #devfestnl
    Available options
    Grade looks like a dream comparing
    to Bash and Ant or Maven
    

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12. #devfestnl
    Decisions made, let's start the journey
    • Android: out of the box
    • iOS: easy, openbackery gradle-xcodePlugin
    • Unity: no plugins
    On Unity there were no plugins, no
    code samples, even no questions on
    Stackoverflow
    

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13. #devfestnl
    So what we're going to do?
    

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14. –Me
    If command line interface is available,
    we can automate
    We are going to create our own Unity
    Gradle plugin!
    

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15. #devfestnl
    Gradle Unity build
    > $UNITY_HOME/Unity -quit -batchmode
    -executeMethod GradleBuildHelper.PerformBuild
    COMMAND LINE
    Unity expose very simple command
    line tool for automation. Main feature:
    invoke any public static method on
    C# side
    

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16. #devfestnl
    Gradle Unity build
    > $UNITY_HOME/Unity -quit -batchmode
    -executeMethod GradleBuildHelper.PerformBuild
    COMMAND LINE
    There is full control on build process
    from C#
    

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17. #devfestnl
    Looks like we have a plan
    

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18. Gradle Unity Build
    Iteration 1. Time to rock
    

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19. Bunch of Gradle tasks we had at the
    end of iteration
    

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20. #devfestnl
    Iteration 1. Result
    Automated
    • Build
    • Unit / Integration tests
    • Beta Distribution
    build.grade
    600+ lines
    

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21. #devfestnl
    Local variables
    def releaseDir = "$buildDir/release"
    task copyReadme(type: Copy) {

    from "$rootDir/README.md"

    into releaseDir

    }
    build.gradle
    Declare and use variables
    

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22. #devfestnl
    Local variables
    def releaseDir = "$buildDir/release"
    build.gradle
    • Feature of the underlying Groovy language
    • Visible only in declaration scope
    

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23. #devfestnl
    Extra properties
    project.ext {

    unityProjectDir = "$rootDir/unity-src"

    sdkVersion = "4.0.0"

    targetPlatform = "Android"

    }
    build.gradle
    Gradle objects like projects, tasks,
    and source sets can hold extra user-
    defined properties.
    

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24. #devfestnl
    Extra properties
    project.ext {

    unityProjectDir = "$rootDir/unity-src"

    }
    build.gradle
    • Part of Gradle domain model
    • Available for projects, tasks, source sets, etc.
    • Accessible via the owning object's ext property
    

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25. #devfestnl
    Local
    variables
    Extra
    properties
    vs.
    part of scope
    for calculations
    local accessibility
    part of project/task/… DSL
    configuration
    globally available
    

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26. #devfestnl
    Tasks
    task helloWorld << {

    println "Hello world!"

    }
    build.gradle
    > gradle helloWorld

    Hello world!
    COMMAND LINE
    Tasks create a public API of the build
    script, available via command line
    Task is a part of the work to do in
    automation process
    

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27. #devfestnl
    Task dependencies
    build.gradle
    task cleanAll(dependsOn: [‘cleanAndroid', 'cleanRelease'])
    build.gradle
    task buildJars(dependsOn: 'android:assemble') {

    ext.getSocialEnvironment = 'master'

    }
    build.gradle
    Gradle do not preserve defined order
    Tasks can be chained
    

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28. #devfestnl
    Task dependencies
    • dependsOn do not preserve defined order
    • but you can order with mustRunAfter
    task cleanAll(dependsOn: [‘cleanAndroid', 'cleanRelease'])
    build.gradle
    

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29. #devfestnl
    dependsOnOrdered
    static dependsOnOrdered(Task task, Task... others) {

    task.dependsOn(others)

    for (int i = 0; i < others.size() - 1; i++) {

    others[i + 1].mustRunAfter(others[i])

    }

    }
    build.gradle
    task cleanAll {

    dependsOnOrdered(cleanAll, *[cleanAndroid, cleanRelease,])

    }
    build.gradle
    Any missing behaviour can be easily
    implemented with Groovy
    

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30. #devfestnl
    task buildUnity(type: Exec) << {

    commandLine "$unityExecutableDir/Unity",

    "-platform=$targetPlatform",

    "-sdkVersion=$sdkVersion",

    '-quit'

    }
    Extending existing tasks
    build.gradle
    • Other: JavaCompile, Jar, Javadoc, Delete…
    • You can create Tasks to extend
    

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31. #devfestnl
    extensions.buildTypes = new BuildTypes(project)

    buildTypes {

    ciDevelop 'ci', getSocialEnvironment: 'testing'

    ciMaster 'ci', getSocialEnvironment: 'master'

    }
    Build Types
    build.gradle
    • Custom implementation of Build Types
    • Switch to native in near future
    

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32. Gradle Unity Build
    Iteration 2. We can do better
    

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33. #devfestnl
    Iteration 1. Problems
    • Big scripts hard to maintain
    • Not DRY enough
    • No separation of concerns
    

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34. This iteration is only about
    refactoring, set of tasks will stay the
    same
    

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35. Build script was separated to 6 files
    + few Groovy utility classes
    

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36. #devfestnl
    Split into several files
    apply from: 'gradle/ci.gradle'
    build.gradle
    task updateVersionInsideUnityProject() { ... }
    task switchBranchAndroid(type: Exec) { ... }
    ci.gradle
    

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37. #devfestnl
    Split into several files
    • Splited into 6 *.gradle files
    • Separated logic
    • DRAWBACK: can’t share common tasks
    apply from: 'gradle/ci.gradle'
    build.gradle
    

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38. #devfestnl
    package im.getsocial.unity

    

    class GetSocialUtils {

    static createDirIfNotExist(dirPath) { ... }

    }
    Move common tasks to Groovy
    GetSocialUtils.groovy
    • Sources location: buildSrc/src/main/groovy/
    • Groovy syntax 95% Java compatible
    Use Groovy, it has tons of syntax
    sugar, code will be much more
    readable
    

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39. #devfestnl
    Move common tasks to Groovy
    import im.getsocial.unity

    

    createDirIfNotExist(“$rootDir/build”)
    build.gradle
    package im.getsocial.unity

    

    class GetSocialUtils {

    static createDirIfNotExist(dirPath) { ... }

    }
    GetSocialUtils.groovy
    

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40. Gradle Unity Build
    Iteration 3. In progress
    

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41. #devfestnl
    Requirements
    • Add support for Build Variants
    • Expose simple configuration DSL
    • Encapsulate logic in plugins
    DSL should be as sexy as Android
    Gradle Plugin DSL
    Besides having debug/release builds
    we also need internal/public test
    apps
    Build logic should be encapsulated
    inside
    

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42. Defined Unity Gradle plugin DSL
    

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43. #devfestnl
    class UnityPlugin implements Plugin {

    void apply(Project project) {

    ...

    }

    }
    Define plugins
    UnityPlugin.groovy
    apply plugin: UnityPlugin
    build.grade
    

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44. #devfestnl
    class UnityPluginExtension {

    String logOutput = 'build/build-log.txt'

    }
    Add extensions
    UnityPlugin.groovy
    void apply(Project project) {

    project.extensions

    .create('unity', UnityPluginExtension)

    }
    UnityPlugin.groovy
    

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45. #devfestnl
    Add extensions
    unity {

    logOutput = 'demo-app-build-log.txt'

    }
    build.grade
    void apply(Project project) {

    project.extensions

    .create('unity', UnityPluginExtension, project)

    }
    UnityPlugin.groovy
    

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46. Takeaways
    

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47. #devfestnl
    Takeaways
    • Automate all the things with Gradle
    • Keep it DRY with Groovy / Java util classes
    • Separate concerns with plugins
    • UnityGradle plugin will be open sourced
    

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48. Thank you!
    Questions?
    Vitaliy Zasadnyy
    @zasadnyy
    Presentation will be available at:
    v.zasadnyy.com/slides/
    

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