A Post: Creating Google Cloud Functions with Kotlin (https://github.com/mwhyte-dev/kotlin-google-cloud-function)

A Post: Creating Google Cloud Functions with Kotlin

A Post: Creating Google Cloud Functions with Kotlin

App.kt

@file:Suppress("unused")

package dev.mwhyte.function

import com.google.cloud.functions.HttpFunction
import com.google.cloud.functions.HttpRequest
import com.google.cloud.functions.HttpResponse
import mu.KotlinLogging
import java.io.IOException

class App : HttpFunction {

    private val logger = KotlinLogging.logger {}

    @Throws(IOException::class)
    override fun service(request: HttpRequest, response: HttpResponse) {
        logger.info { "hello world" }
        response.writer.write("FUNCTION COMPLETE")
    }
}

build.gradle.kts

import java.lang.invoke.MethodHandles.invoker

val invoker by configurations.creating

plugins {
    id("org.jetbrains.kotlin.jvm") version "1.3.72"
    id("com.github.johnrengelman.shadow") version "6.0.0"
    application
}

repositories {
    jcenter()
}

dependencies {
    implementation(platform("org.jetbrains.kotlin:kotlin-bom"))
    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    implementation("io.github.microutils:kotlin-logging:1.11.5")
    implementation("com.google.cloud.functions:functions-framework-api:1.0.1")
    invoker("com.google.cloud.functions.invoker:java-function-invoker:1.0.0-alpha-2-rc5")

    testImplementation("org.jetbrains.kotlin:kotlin-test")
    testImplementation("org.jetbrains.kotlin:kotlin-test-junit")
    testImplementation("org.mockito:mockito-core:3.5.10")
    testImplementation("com.google.truth:truth:1.0.1")
    testImplementation("com.google.guava:guava-testlib:29.0-jre")
}

application {
    mainClassName = "dev.mwhyte.function.AppKt"
}

task<JavaExec>("runFunction") {
    main = "com.google.cloud.functions.invoker.runner.Invoker"
    classpath(invoker)
    inputs.files(configurations.runtimeClasspath, sourceSets["main"].output)
    args(
        "--target", project.findProperty("runFunction.target") ?: "dev.mwhyte.function.App",
        "--port", project.findProperty("runFunction.port") ?: 8080
    )
    doFirst {
        args("--classpath", files(configurations.runtimeClasspath, sourceSets["main"].output).asPath)
    }
}

tasks.named("build") {
    dependsOn(":shadowJar")
}

task("buildFunction") {
    dependsOn("build")
    copy {
        from("build/libs/" + rootProject.name + "-all.jar")
        into("build/deploy")
    }
}

buildFunction.sh

❯ ./gradlew buildFunction

BUILD SUCCESSFUL in 1s
10 actionable tasks: 10 up-to-date

gcp-deploy.sh

❯ gcloud functions deploy my-test-function \
--entry-point=dev.mwhyte.function.App \
--source=build/deploy --runtime=java11 --trigger-http \
--allow-unauthenticated
Deploying function (may take a while - up to 2 minutes)...⠹

runFunction.sh

❯ ./gradlew runFunction

> Task :runFunction
2021-07-13 20:21:00.608:INFO:oejs.Server:main: jetty-9.4.26.v20200117; built: 2020-01-17T12:35:33.676Z; git: 7b38981d25d14afb4a12ff1f2596756144edf695; jvm 15.0.1+9
2021-07-13 20:21:00.646:INFO:oejsh.ContextHandler:main: Started o.e.j.s.ServletContextHandler@467aecef{/,null,AVAILABLE}
2021-07-13 20:21:00.671:INFO:oejs.AbstractConnector:main: Started ServerConnector@3d24753a{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2021-07-13 20:21:00.672:INFO:oejs.Server:main: Started @485ms
Jul 13, 2021 8:21:00 PM com.google.cloud.functions.invoker.runner.Invoker logServerInfo
INFO: Serving function...
Jul 13, 2021 8:21:00 PM com.google.cloud.functions.invoker.runner.Invoker logServerInfo
INFO: Function: dev.mwhyte.function.App
Jul 13, 2021 8:21:00 PM com.google.cloud.functions.invoker.runner.Invoker logServerInfo
INFO: URL: http://localhost:8080/
<==========---> 80% EXECUTING [15s]
> :runFunction

runFunction2.sh

❯ ./gradlew runFunction -PrunFunction.target=dev.mwhyte.function.App -PrunFunction.port=8080

> Task :runFunction
INFO: Function: dev.mwhyte.function.App
Jul 13, 2021 8:24:24 PM com.google.cloud.functions.invoker.runner.Invoker logServerInfo
INFO: URL: http://localhost:8080/
<==========---> 80% EXECUTING [8s]
> :runFunction