Publish APK over S3 using Gradle

build.gradle

buildscript {
    dependencies {
        classpath "com.amazonaws:aws-java-sdk:1.3.11"
    }
}

def awsCredentials = new BasicAWSCredentials(awsAccessKey, awsSecretKey)

// Publish APK and mapping file over SCP
android.applicationVariants.all { variant ->
    if (variant.buildType.name != "release") {
        return
    }
    def buildTypeName = variant.buildType.name
    def flavorName = variant.productFlavors[0].name
    def publishWebApkTask = task("publishWeb${flavorName.capitalize()}").doLast {
        def publishDir = file("${buildDir}/publish")
        def versionName = variant.versionName

        def srcApkFile = variant.outputs.find { variantOutput -> variantOutput instanceof com.android.build.gradle.api.ApkVariantOutput }.outputFile
        def baseName = "drivedroid-${flavorName}-${versionName}"
        def dstApkFile = file("${publishDir}/${baseName}.apk")

        def srcMappingFile = file("${buildDir}/outputs/mapping/${flavorName}/${buildTypeName}/mapping.txt")
        def dstMappingFile = file("${publishDir}/${baseName}-mapping.txt")

        publishDir.mkdirs()

        dstApkFile.bytes = srcApkFile.bytes
        dstMappingFile.bytes = srcMappingFile.bytes

        def amazonS3 = new AmazonS3Client(awsCredentials)
        amazonS3.putObject("your-bucket", "path/where/to/store/your/apk/${dstApkFile.name}", dstApkFile)
        amazonS3.putObject("your-bucket", "path/where/to/store/your/apk/${dstMappingFile.name}", dstMappingFile)
    }
    publishWebApkTask.group = "publish"
    publishWebApkTask.dependsOn variant.outputs.first().assemble
}