What is lambda-function

Kotlin native serverless lambda function runtime for Azure Functions custom handler, lambda-function currently supports develop on Linux and Windows only.

lambda-function is based on ktor-server-core and ktor-server-cio, it means all ktor plugins supports native platform can be used on this runtime.

How to use lambda-function

lambda-function provided a Gradle plugin to running functions, packaging and deploy to Azure Portal, it's optional, but recommend to apply.

Install Azure Function dev tools

Before starting, you need to install Azure Function Core Tools and Azure Command-Line Interface (CLI), following Microsoft Azure documents to learn how to install

• Azure Function Core Tools
• Azure Command-Line Interface (CLI)

Apply Gradle Plugin

// settings.gradle.kts
pluginManagement {
    repositories {
        mavenCentral()
        gradlePluginPortal()
        maven("https://repo.rtast.cn/packages")
    }
}

// build.gradle.kts
plugins {
    // Replace the version to latest version
    id("cn.rtast.lambdafunction") version "0.1.1"
}

repositories {
    mavenCentral()
    maven("https://repo.rtast.cn/packages")
}

/**
 * Configure the required json file to your own,
 * All options except `appName` are optional, if not set, plugin fallbak to builtin config
 */
lambdaFunction {
    appName = "myazurefunction"
    hostJsonFile = file("./host.json")
    functionJsonFile = file("./function.json")  // do not change this if you know what are you doing
    localSettingsFile = file("./local.settings.json")
    // Including resources files
    customResources.addAll(*file("src/commonMain/resources").listFiles())
}

Builtin config JSON files

• host.json
• function.json
• local.settings.json

Install dependencies

// settings.gradle.kts

kotlin {
    linuxX64()
    mingwX64()

    targets.withType<KotlinNativeTarget>().configureEach {
        binaries { executable { entryPoint = "com.example.main" } }
    }

    sourceSets {
        commonMain.dependencies {
            implementation("cn.rtast.lambdafunction:azure-runtime:0.1.1")
        }
    }
}

// com/example/main.kt

fun main(): Unit = runAzureLambda {
    routing {
        get("/") {
            call.respond("Hello index")
        }

        get("/{name}") {
            call.respond("Hello ${call.pathParameters["name"]}")
        }
    }
}

Running Function

./gradlew azureFunctionRun

Packaging Function

./gradlew packageLinuxX64
./gradlew packageMingwX64

Deploying Function to Azure Portal

Login into Azure Portal by executing az login in terminal before execute Gradle task

./gradlew deployLinuxX64
./gradlew deployMingwX64

Running Function Manually

Click to expand contents

Building executable binary file

The function run directory file tree should look like:

.
├── azure-test.kexe
├── delegate_
│   └── function.json
├── host.json
└── local.settings.json
```0.0.

```shell
./gradlew linkReleaseExecutableLinuxX64

mkdir build/lambda-function-run -p
mkdir build/lambda-function-run/delegate_ -p
chmod +x build/bin/linuxX64/releaseExecutable/azure-test.kexe
cp build/bin/linuxX64/releaseExecutable/azure-test.kexe build/lambda-function-run

# Copying host.json local.settings.json to `build/lambda-function-run`
# Replace {{AUTO_DETECTED}} in host.json with `azure-test.kexe` 
# Copying function.json to `build/lambda-function-run/delegate_`

cd build/lambda-function-run
func start

Functions server listening on port http://127.0.0.1:7071

curl http://127.0.0.1:7071/  # Expect response: Hello index
curl http://127.0.0.1:7071/RTAkland  # Expect response: Hello RTAkland

Packaging function to zip

cd build/lambda-function-run
func pack

Deploying to Azure Portal

cd build/lambda-function-run
func azure functionapp publish myfunction

Open Source

lambda-function Licensed under Apache-2.0