serverless-functions-go

README

Serverless Functions Go 💜

Scaleway Serverless Functions Go is a framework which simplify Scaleway Serverless Functions local development. It brings features to debug your function locally and provides input/output data format of Scaleway Serverless Functions.

This library helps you to write functions but for deployment refer to the documentation.

Get started with Scaleway Functions (we support multiple languages 🚀):

• Scaleway Serverless Functions Documentation
• Scaleway Serverless Framework plugin
• Scaleway Serverless Examples
• Scaleway Cloud Provider

Testing frameworks for Scaleway Serverless Functions in other languages can be found here:

• Node
• Python

⚙️ Quickstart

To get this package:

 go get github.com/scaleway/serverless-functions-go

Add in cmd/main.go the following code:

import "github.com/scaleway/serverless-functions-go/local"

func main() {
	// Replace "Handle" with your function handler name if necessary
	local.ServeHandler(Handle, local.WithPort(8080))
}

For more information on how to use the framework check the  usage section.

🚀 Features

This repository aims to provide a better experience on: local testing, utils, documentation

🏡 Local testing

What this package does:

• Format Input: Serverless Functions have a specific input format encapsulating the body received by functions to add some useful data. The local testing package lets you interact with the formatted data.
• Advanced debugging: To improve developer experience you can run your handler locally and debug it by running your code step-by-step or reading output directly before deploying it.

What this package does not:

• Simulate performance: Scaleway FaaS lets you choose different options for CPU/RAM that can have an impact on your development. This package does not provide specific limits for your function on local testing but you can add Profile your application or you can use our metrics available in Scaleway Console to monitor your application.
• Build functions: When your function is uploaded we build it in an environment that can be different than yours. Our build pipelines support tons of different packages but sometimes it requires a specific setup, for example, if your function requires a specific 3D system library. If you have compatibility issues, please see the help section.

🔬 Advanced usage

To run the function locally you need to add an entry point to serve your function.

This entrypoint should be put in a directory not required by your handler, e.g. cmd/main.go.

In your run/main.go add the following code to invoke your function :

package main

import (
  // "localfunc" is the module name located in your go.mod. To generate a go.mod with localfunc as name you
  // can use the following command : go mod init localfunc
  // Or you can replace "localfunc" with your own module name.
	localfunc "github.com/scaleway/serverless-functions-go/examples/handler"
	"github.com/scaleway/serverless-functions-go/local"
)

func main() {
	// Replace "Handle" with your function handler name if necessary
	local.ServeHandler(localfunc.Handle, local.WithPort(8080))
}

This file will expose your handler on a local web server allowing you to test your function.

Some information will be added to requests for example specific headers. For local development, additional header values are hardcoded to make it easy to differentiate them. In production, you will be able to observe headers with exploitable data.

Local testing part of this framework does not aim to simulate 100% production but it aims to make it easier to work with functions locally.

Cli

To run the server locally: go run cmd/main.go

VS Code

Open cmd/main.go and open the "Run and Debug" pannel to execute or debug your function there is no special configuration to add to VSCode.

Goland

The IDE will generate a run configuration for you, open cmd/main.go and run the main.

❓ FAQ

Why do I need an additional package to call my function?

Your Function Handler can be served by a simple HTTP server but Serverless Ecosystem involves a lot of different layers that will change changes the headers, input and output of your function. This package aims to simulate everything your request will go through to help you debug your application properly. This library is not mandatory to use Scaleway Serverless Functions.

How my function will be deployed

To deploy your function please refer to our official documentation.

Do I need to deploy my function differently?

No. This framework does not affect deployment nor performance.

🏛️ Architecture

To make development and understanding of this repository we tried to keep the path of the request natural.

• framework folder is used to store all the code that you can import into your project
• local contains all the cool tools to work locally with your function 😎

🛟 Help & support

• Scaleway support is available on Scaleway Console.
• Additionally, you can join our Slack Community

🎓 Contributing

Additionally we love to share things with the community and we want to expose receipts to the public. That's why we make our framework publicly available to help the community!

Do not hesitate to raise issues and pull requests we will have a look at them.

If you are looking for a way to contribute please read CONTRIBUTING.md.

📭 Reach Us

We love feedback. Feel free to:

• Open a Github issue
• Send us a message on the Scaleway Slack community, in the #serverless-functions channel.