Use Kotlin DSL in appengine/ktor sample, bump versions

appengine/ktor/build.gradle.kts

@@ -0,0 +1,52 @@
+plugins {
+    kotlin("jvm") version "1.4.20"
+    war
+    id("com.google.cloud.tools.appengine") version "2.4.1"
+}
+
+repositories {
+    mavenCentral()
+    // kotlinx-html-jvm is not available in mavenCentral yet
+    // See https://github.com/Kotlin/kotlinx.html/issues/173
+    jcenter {
+        content {
+            includeModule("org.jetbrains.kotlinx", "kotlinx-html-jvm")
+        }
+    }
+}
+
+require (JavaVersion.current() <= JavaVersion.VERSION_11) {
+    "AppEngine supports only Java 8 or 11 for now, the current Java is ${JavaVersion.current()}"
+}
+
+dependencies {
+    implementation(platform("io.ktor:ktor-bom:1.5.1"))
+    implementation("io.ktor:ktor-server-servlet")
+    implementation("io.ktor:ktor-html-builder")
+    implementation("com.google.cloud:google-cloud-logging-logback:0.117.0-alpha")
+
+    runtimeOnly("com.google.appengine:appengine:1.9.86")
+}
+
+appengine {
+    deploy {
+        projectId = "GCLOUD_CONFIG"
+        version = "GCLOUD_CONFIG"
+    }
+}
+
+tasks {
+    withType<JavaCompile>().configureEach {
+        options.encoding = "UTF-8"
+    }
+
+    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
+        kotlinOptions {
+            jvmTarget = "1.8"
+        }
+    }
+
+    register("run") {
+        dependsOn("appengineRun")
+    }
+}

appengine/ktor/gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.parallel=true
+
+kotlin.code.style=official
+kotlin.parallel.tasks.in.project=true

appengine/ktor/settings.gradle.kts

@@ -0,0 +1,15 @@
+pluginManagement {
+    // resolutionStrategy enables using plugins { id("com.google.cloud.tools.appengine") } syntax
+    // It won't be needed when the plugin publishes
+    // com.google.cloud.tools.appengine:com.google.cloud.tools.appengine.gradle.plugin
+    // artifact to Sonatype OSSRH
+    resolutionStrategy {
+        eachPlugin {
+            if (requested.id.id == "com.google.cloud.tools.appengine") {
+                useModule("com.google.cloud.tools:appengine-gradle-plugin:${requested.version}")
+            }
+        }
+    }
+}
+
+rootProject.name = "appengine-ktor"