ptzagk / faas

:whale: Functions as a Service - a serverless framework for Docker & Kubernetes

Functions as a Service (OpenFaaS)

OpenFaaS is a framework for building serverless functions with Docker which has first class support for metrics. Any process can be packaged as a function enabling you to consume a range of web events without repetitive boiler-plate coding.

Highlights

• Ease of use through UI portal and one-click install
• Write functions in any language for Linux or Windows and package in Docker/OCI image format
• Portable - runs on existing hardware or public/private cloud - Kubernetes or Docker Swarm
• CLI available with YAML format for templating and defining functions
• Auto-scales as demand increases

Overview of OpenFaaS

Function Watchdog

• You can make any Docker image into a serverless function by adding the Function Watchdog (a tiny Golang HTTP server)
• The Function Watchdog is the entrypoint allowing HTTP requests to be forwarded to the target process via STDIN. The response is sent back to the caller by writing to STDOUT from your application.

Gateway

• The API Gateway provides an external route into your functions and collects Cloud Native metrics through Prometheus.
• Your API Gateway will scale functions according to demand by altering the service replica count in the Docker Swarm or Kubernetes API.
• A UI is baked in allowing you to invoke functions in your browser and create new ones as needed.

CLI

Any container or process in a Docker container can be a serverless function in FaaS. Using the FaaS CLI you can deploy your functions or quickly create new functions from templates such as Node.js or Python.

CLI walk-through

Let's have a quick look at an example function url_ping which connects to a remote web server and returns the HTTP code from the response. It's written in Python.

import requests

def handle(req):
        r =  requests.get(req, timeout = 1)
        print(req +" => " + str(r.status_code))

handler.py

$ curl -sSL https://cli.openfaas.com | sudo sh

Install the faas-cli which is also available on brew

Clone the samples and templates from Github:

$ git clone https://github.com/alexellis/faas-cli
$ cd faas-cli

Define your functions in YAML - or deploy via the API Gateway's UI.

provider:
  name: faas
  gateway: http://localhost:8080

functions:
  url_ping:
    lang: python
    handler: ./sample/url_ping
    image: alexellis2/faas-urlping

Example function YAML file - urlping.yaml

$ faas-cli -action build -f ./urlping.yaml

Build a Docker image using the Python handler in ./sample/url_ping

$ faas-cli -action deploy -f ./urlping.yaml

Deploy the new image to the gateway defined in the YAML file.

If your gateway is remote or part of a multi-host Swarm - you can also use the CLI to push your image to a remote registry or the Hub with faas-cli -action push

$ curl -d "https://cli.openfaas.com" http://localhost:8080/function/url_ping/
https://cli.openfaas.com => 200

Test out the function with the URL https://cli.openfaas.com => 200

Sample functions are available in the Github repository in a range of programming languages.

Get started with OpenFaaS

Closing Keynote at Dockercon 2017

Functions as a Service or FaaS was a winner in the Cool Hacks contest for Dockercon 2017.

• Watch my FaaS keynote at Dockercon 2017

If you'd like to find the functions I used in the demos head over to the faas-dockercon repository.

Background story

This is my original blog post on FaaS from January: Functions as a Service blog post

TestDrive

Docker Playground

You can quickly start OpenFaaS on Docker Swarm online using the community-run Docker playground: play-with-docker.com (PWD) by clicking the button below:

Docker Swarm

A set of one-line scripts are provided to help you quickly test-drive OpenFaaS on Docker Swarm with a set of sample functions as defined in the provided docker-compose.yml file.

• deploy_stack.sh - for OSX/Linux on x86_64
• deploy_stack.armhf.sh - for Linux on ARM (Raspberry Pi for example)
• deploy_stack.ps1 - for Windows

Kubernetes

Alternatively if you have a Kubernetes cluster you can start here.

Begin the TestDrive with Docker Swarm

Here is a screenshot of the API gateway portal - designed for ease of use.

Community

Have you written a blog about OpenFaaS? Send a Pull Request to the community page below.

• Read blogs/articles and find events about OpenFaaS

If you'd like to join OpenFaaS community Slack channel to chat with contributors or get some help - then send a Tweet to @alexellisuk or open a Github issue.

Roadmap and contributing

OpenFaaS is written in Golang and is MIT licensed - contributions are welcomed whether that means providing feedback, testing existing and new feature or hacking on the source. To get started you can checkout the roadmap and contribution guide or browse the open issues on Github.

Highlights:

• New: Kubernetes support via FaaS-netes plugin
• New: FaaS CLI and easy install via curl and brew
• New: Windows function support
• In development: Asynchronous/long-running OpenFaaS functions via NATS Streaming - Test it using this guide

Example of a Grafana dashboard linked to OpenFaaS showing auto-scaling live in action:

Sample dashboard JSON file available here