Get Things Done with Gradle Custom Tasks

Get the job done automatically with Gradle Custom Tasks on the CI.

Transcript

1. Get Things Done with
   Gradle Custom Tasks
   Keishin Yokomaku (@KeithYokoma)
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2. Get Things Done with Gradle Custom Tasks
   About Me
   ▸ Keishin Yokomaku
   ▸ @KeithYokoma: GitHub / Twitter / Qiita / Stack Overflow
   ▸ Merpay, Inc. / Engineer
   ▸ Fun: Gymnastics / Cycling / Photography / Motorsport / Camping
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3. Get Things Done with Gradle Custom Tasks
   Daily workflow
   1. Merpay: ⌨ Code and Verify
   2. Merpay: Git Push
   3. Merpay: Build and Deploy the artifact
   4. Mercari: Update the Merpay artifact for integration
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4. Get Things Done with Gradle Custom Tasks
   Daily workflow
   1. Feature Development
   ▸ Merging feature branches into master
   2. QA
   ▸ Merging bugfix branches into release/*
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   master
   release/*
   

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5. Get Things Done with Gradle Custom Tasks
   Continuous Integration
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6. Get Things Done with Gradle Custom Tasks
   Continuous Integration
   ▸ CircleCI 2.1
   ▸ Docker: the first-class citizen
   ▸ Configuration as a Code
   ▸ Flexible workflow definitions
   ▸ Git triggers
   ▸ Nightly
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7. Get Things Done with Gradle Custom Tasks
   Continuous Integration
   ▸ CircleCI 2.1 - Workflow with git triggers
   ▸ Mainstream: master and release/*
   ▸ Branches: feature / topic branches
   ▸ Tags: git tags
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8. Get Things Done with Gradle Custom Tasks
   Continuous Integration
   ▸ CircleCI 2.1 - Nightly Workflow
   ▸ Protobuf update: 12:00 and 19:00 JST every weekdays
   ▸ Release branch merge: 12:00 and 19:00 JST every weekdays
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9. Get Things Done with Gradle Custom Tasks
   Mainstream Workflow
   ▸ Install dependencies
   ▸ Test
   ▸ Assemble / Collect test coverage
   ▸ Deploy the artifacts
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10. Get Things Done with Gradle Custom Tasks
    Branches Workflow
    ▸ Install dependencies
    ▸ Assemble and test debug and release variants
    ▸ Collect test coverage / Static code analysis
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11. Get Things Done with Gradle Custom Tasks
    Tags Workflow
    ▸ Install dependencies
    ▸ Test
    ▸ Assemble
    ▸ Deploy
    ▸ Execute a Gradle Custom Task: Open a pull request in Mercari repository
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12. Get Things Done with Gradle Custom Tasks
    Protobuf Update Workflow
    ▸ Execute a Gradle Custom Task: Overwrite the version with the latest one
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13. Get Things Done with Gradle Custom Tasks
    Release Branch Merge Workflow
    ▸ Execute a Gradle Custom Task: git merge and push to create a pull request
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14. Get Things Done with Gradle Custom Tasks
    Gradle Custom Tasks
    ▸ A step for a workflow
    ▸ Open a pull request in Mercari repository
    ▸ Overwrite the version with the latest one
    ▸ git merge and push to create a pull request
    ▸ Static code analysis result aggregation
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15. Get Things Done with Gradle Custom Tasks
    Steps to make Gradle Custom Tasks work
    1. Put a custom task implementation under buildSrc
    2. Register the custom task in build.gradle of project root
    3. Run the Gradle command!
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16. Get Things Done with Gradle Custom Tasks
    Prep for buildSrc
    ▸ Project Root/buildSrc
    ▸ build.gradle.kts
    ▸ src
    ▸ main
    ▸ java
    ▸ com.your.package
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17. Get Things Done with Gradle Custom Tasks
    Prep for buildSrc
    // build.gradle.kts under buildSrc directory
    repositories {
    jcenter()
    }
    plugins {
    `kotlin-dsl`
    `java-gradle-plugin`
    }
    dependencies {
    implementation(gradleApi())
    }
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18. Get Things Done with Gradle Custom Tasks
    Implement your Gradle custom task in Kotlin
    open class MyCustomTask : DefaultTask() {
    @Input
    lateinit var parameter: String
    @TaskAction
    fun execute() {
    println(parameter)
    }
    }
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19. Get Things Done with Gradle Custom Tasks
    Class needs to be open
    open class MyCustomTask : DefaultTask() {
    @Input
    lateinit var parameter: String
    @TaskAction
    fun execute() {
    println(parameter)
    }
    }
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20. Get Things Done with Gradle Custom Tasks
    Extends DefaultTask
    open class MyCustomTask : DefaultTask() {
    @Input
    lateinit var parameter: String
    @TaskAction
    fun execute() {
    println(parameter)
    }
    }
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21. Get Things Done with Gradle Custom Tasks
    Task parameter with @Input annotation
    open class MyCustomTask : DefaultTask() {
    @Input
    lateinit var parameter: String
    @TaskAction
    fun execute() {
    println(parameter)
    }
    }
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22. Get Things Done with Gradle Custom Tasks
    Task body with @TaskAction
    open class MyCustomTask : DefaultTask() {
    @Input
    lateinit var parameter: String
    @TaskAction
    fun execute() {
    println(parameter)
    }
    }
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23. Get Things Done with Gradle Custom Tasks
    Registering the custom task
    // build.gradle.kts in the project root
    tasks.register(“myTask”) {
    parameter = “Hello, World!”
    }
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24. Get Things Done with Gradle Custom Tasks
    Have a name of your custom task: “myTask”
    // build.gradle.kts in the project root
    tasks.register(“myTask”) {
    parameter = “Hello, World!”
    }
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25. Get Things Done with Gradle Custom Tasks
    Set the parameter values
    // build.gradle.kts in the project root
    tasks.register(“myTask”) {
    parameter = “Hello, World!”
    }
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26. Get Things Done with Gradle Custom Tasks
    Check your task
    $ ./gradlew tasks
    ……
    Android Tasks
    —————
    ……
    Build Tasks
    —————
    ……
    BUILD SUCCESSFUL in 7s
    1 actionable task: 1 executed
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27. Get Things Done with Gradle Custom Tasks
    Registering the custom task
    // build.gradle.kts in the project root
    tasks.register(“myTask”) {
    group = “Greeting”
    description = “Print a greeting message”
    parameter = “Hello, World!”
    }
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28. Get Things Done with Gradle Custom Tasks
    Check your task
    $ ./gradlew tasks
    ……
    Android Tasks
    —————
    ……
    Greeting Tasks
    —————
    myTask - Print a greeting message
    ……
    BUILD SUCCESSFUL in 7s
    1 actionable task: 1 executed
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29. Get Things Done with Gradle Custom Tasks
    Run!
    $ ./gradlew myTask
    > Task: myTask
    Hello, World!
    BUILD SUCCESSFUL in 1s
    1 actionable task: 1 executed
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30. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    ▸ Premise:
    ▸ Multiple Android modules inside the project
    ▸ Requirements:
    ▸ Collect all the Lint report and unify them
    ▸ Usage:
    ▸ $ ./gradlew lint aggregateLintReport
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31. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    ▸ Dependencies:
    ▸ Writers in java.io package
    ▸ XML utilities in groovy.util package
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32. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    open class AndroidLintReportAggregation : DefaultTask() {
    @TaskAction
    fun aggregate() {
    // 1. Collect all Lint report files
    // 2. Create a file for aggregation
    // 3. Copy nodes in each file to aggregated file
    // 4. Print the aggregated file path
    }
    }
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33. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 1. Collect all Lint report files
    val reports = project.subprojects.map { subproject ->
    File(“${subproject.buildDir.absolutePath}/reports”)
    }.map { dir ->
    dir.walk().find { file ->
    file.name == “lint-results.xml”
    }
    }.filterNotNull()
    }
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34. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 2. Create a file for aggregation
    val aggregatedFile = File(“${project.rootDir}/result.xml”)
    if (aggregatedFile.exists().not()) {
    aggregatedFile.createNewFile())(
    }
    }
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35. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 3. Copy nodes in each file to aggregated file
    val printer = XmlNodePrinter(
    PrintWriter(FileWriter(aggregatedFile))
    ).apply {
    write(“\n”)
    }
    printer.isExpandEmptyElements = true
    }
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36. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 3. Copy nodes in each file to aggregated file
    val rootNode = Node(
    null,
    “issues”,
    mapOf(“format” to “5”, “by” to “lint 3.4.0”)
    )
    }
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37. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 3. Copy nodes in each file to aggregated file
    val rootNode = // ……
    reports.forEach { report ->
    val elements = XmlParser().parse(report).children()
    if (elements.isEmpty()) {
    return@forEach
    }
    }
    }
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38. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 3. Copy nodes in each file to aggregated file
    val rootNode = // ……
    reports.forEach { report ->
    val elements = // ……
    elements.map { element ->
    if (element !is Node) {
    return@map
    }
    rootNode.append(element)
    }
    }
    }
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39. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 3. Copy nodes in each file to aggregated file
    val rootNode = // ……
    // ……
    printer.print(rootNode)
    }
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40. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport
    @TaskAction
    fun aggregate() {
    // 4. Print the aggregated file path
    println(“Aggregated to ${aggregatedFile.absolutePath}”)
    }
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41. Get Things Done with Gradle Custom Tasks
    Example: aggregateLintReport - What’s good?
    ▸ No change on static code analysis configuration when you have a new module
    ▸ e.g. Danger to report the Lint issues
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    android_lint.report_file = “./reports.xml”
    android_lint.filtering = true
    android_lint.lint(inline_mode: true)
    

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42. Get Things Done with Gradle Custom Tasks
    Steps to make Gradle Custom Tasks work
    1. Put a custom task implementation under buildSrc
    2. Register the custom task in build.gradle of project root
    3. Run the Gradle command!
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43. Get Things Done with Gradle Custom Tasks
    Some Discussions
    ▸ Is it OK to do some Network I/O?
    ▸ Definitely!
    ▸ You can enhance your task with Web APIs (e.g. GitHub API, CircleCI API)
    ▸ Can I use Git commands from the task?
    ▸ Yes!
    ▸ Use org.eclipse.jgit library to make it easier
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44. Get Things Done with
    Gradle Custom Tasks
    Keishin Yokomaku (@KeithYokoma)
    Shibuya.apk #36
    

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