-> https://github.com/obfusk/reproducible-apk-tools#gradle-integration | reproducible-apk-tools gradle integration

build1.gradle

// NB: assumes reproducible-apk-tools is a submodule in the app repo's
// root dir; adjust the path accordingly if it is found elsewhere
project.afterEvaluate {
    tasks.compileReleaseArtProfile.doLast {
        outputs.files.each { file ->
            if (file.toString().endsWith(".profm")) {
                exec {
                    commandLine(
                        "../reproducible-apk-tools/inplace-fix.py",
                        "sort-baseline", file
                    )
                }
            }
        }
    }
}

build2.gradle

// NB: assumes reproducible-apk-tools is a submodule in the app repo's
// root dir; adjust the path accordingly if it is found elsewhere
android {
    applicationVariants.all { variant ->
        variant.outputs.each { output ->
            variant.packageApplicationProvider.get().doLast {
                def tools = "${android.sdkDirectory}/build-tools/${android.buildToolsVersion}"
                exec {
                    // set PATH for zipalign
                    environment "PATH", "${tools}:$System.env.PATH"
                    commandLine(
                        "../reproducible-apk-tools/inplace-fix.py",
                        "--zipalign", "fix-newlines", output.outputFile,
                        "META-INF/services/*"
                    )
                }
                // re-sign w/ apksigner if needed
                if (variant.signingConfig != null) {
                    def sc = variant.signingConfig
                    exec {
                        environment "KS_PASS", sc.storePassword
                        environment "KEY_PASS", sc.keyPassword
                        commandLine(
                            "${tools}/apksigner", "sign", "-v",
                            "--ks", sc.storeFile,
                            "--ks-pass", "env:KS_PASS",
                            "--ks-key-alias", sc.keyAlias,
                            "--key-pass", "env:KEY_PASS",
                            output.outputFile
                        )
                    }
                }
            }
        }
    }
}