tinyFaaS: A Lightweight FaaS Platform for Edge Environments

tinyFaaS is a lightweight FaaS (Function-as-a-Service) platform for edge environment with a focus on performance in constrained environments.

Research

To use tinyFaaS in the version used in our paper, use git checkout v0.1. If you use this software in a publication, please cite it as:

Text

T. Pfandzelter and D. Bermbach, tinyFaaS: A Lightweight FaaS Platform for Edge Environments, Proceedings of the 2020 IEEE International Conference on Fog Computing (ICFC '20), Sydney, Australia, 2020, pp. 17-24, DOI: 10.1109/ICFC49376.2020.00011.

BibTeX

@inproceedings{pfandzelter_tinyfaas:_2020,
    author = "Pfandzelter, Tobias and Bermbach, David",
    title = "tinyFaaS: A Lightweight FaaS Platform for Edge Environments",
    booktitle = "Proceedings of the 2020 IEEE International Conference on Fog Computing (ICFC '20)",
    year = 2020,
    publisher = "IEEE",
    pages = "17--24",
    doi = "10.1109/ICFC49376.2020.00011"
}

For a full list of publications, please see our website.

License

The code in this repository is licensed under the terms of the MIT license.

Instructions

Disclaimer: Please note that this will use your computer's Docker instance to manage containers and will allow anyone in your network to start Docker containers with arbitrary code. If you don't know what this means you do not want to run this on your computer. Additionally, note that this software is provided as a research prototype and is not production-ready.

About

tinyFaaS comprises the management service, the reverse proxy, and a number of function handlers. In order to run tinyFaaS, the management service has to be deployed. It will then automatically start the reverse proxy. Once a function is deployed to tinyFaaS, function handlers are created automatically.

Prerequisites

Before you get started, make sure you have the following dependencies installed:

• Go (>=v1.20) to compile management service and reverse proxy
• Docker (>=v24)
• Make

Note that tinyFaaS is intended for Linux hosts (x86_64 and arm64). Due to limitations of Docker Desktop for Mac, installing and running docker-mac-net-connect is necessary to run tinyFaaS on macOS hosts. Running tinyFaaS on Windows computers (native or through WSL) is probably possible but has not been tested and is thus not recommended.

Getting Started

Start tinyFaaS with:

make

The reverse proxy will be started automatically. Please note that you cannot use tinyFaaS until the reverse proxy is running.

Managing Functions

To manage functions on tinyFaaS, use the included scripts included in ./src/scripts.

To upload a function, run upload.sh {FOLDER} {NAME} {ENV} {THREADS}, where {FOLDER} is the path to your function code, {NAME} is the name for your function, {ENV} is the environment you would like to use (python3, nodejs, or binary), and {THREADS} is a number specifying the number of function handlers for your function. For example, you might call ./scripts/upload.sh "./test/fns/sieve-of-eratosthenes" "sieve" "nodejs" 1 to upload the sieve of Eratosthenes example function included in this repository. This requires the zip, base64, and curl utilities.

Alternatively, you can also upload functions from a zipped file available at some URL. Use the included script as a starting point: uploadURL.sh {URL} {NAME} {ENV} {THREADS} {SUBFOLDER_PATH}, where {URL} is the URL to a zip that has your function code, {SUBFOLDER_PATH} is the folder of the code within that zip (use / if the code is in the top-level), {NAME} is the name for your function, {ENV} is the environment, and {THREADS} is a number specifying the number of function handlers for your function. For example, you might call uploadURL.sh "https://github.com/OpenFogStack/tinyFaas/archive/main.zip" "tinyFaaS-main/test/fns/sieve-of-eratosthenes" "sieve" "nodejs" 1 to upload the sieve of Eratosthenes example function included in this repository.

To get a list of existing functions, run list.sh.

To delete a function, run delete.sh {NAME}, where {NAME} is the name of the function you want to remove.

Additionally, we provide scripts to read logs from your function and to wipe all functions from tinyFaaS.

Writing Functions

This tinyFaaS prototype only supports functions written for NodeJS 20, Python 3.9, and binary functions.

NodeJS 20

Your function must be supplied as a Node module with the name fn that exports a single function that takes the req and res parameters for request and response, respectively. res supports the send() function that has one parameter, a string that is passed to the client as-is.

To get started with functions, use the example sieve of Eratosthenes function in ./test/fns/sieve-of-eratosthenes.

Python 3.9

Your function must be supplied as a file named fn.py that exposes a method fn that is invoked for every function invocation. This method must accept a string as an input (that can also be None) and must provide a string as a return value. You may also provide a requirements.txt file from which dependencies will be installed alongside your function. Any other data you provide will be available.

To get started with this type of function, use the example echo function in ./test/fns/echo.

Binary

Your function must be provided as a fn.sh shell script that is invoked for every function call. This shell script may also call other binaries as needed. Input data is provided from stdin. Output responses should be provided on stdout.

To get started with this type of function, use the example echo-binary function in ./test/fns/echo-binary.

Calling Functions

tinyFaaS supports different application layer protocols at its reverse proxy. Different protocols are useful for different use-cases: CoAP for lightweight communication, e.g., for IoT devices; HTTP to support traditional web applications; GRPC for inter-process communication.

CoAP

To call a tinyFaaS function using its CoAP endpoint, make a GET or POST request to coap://{HOST}:{PORT}/{NAME} where {HOST} is the address of the tinyFaaS host, {PORT} is the port for the tinyFaaS CoAP endpoint (default is 5683), and {NAME} is the name of your function. You may include data in any form you want, it will be passed to your function.

Unfortunately, curl does not yet support CoAP, but a number of other tools are available.

HTTP

To call a tinyFaaS function using its HTTP endpoint, make a GET or POST request to http://{HOST}:{PORT}/{NAME} where {HOST} is the address of the tinyFaaS host, {PORT} is the port for the tinyFaaS HTTP endpoint (default is 80), and {NAME} is the name of your function. You may include data in any form you want, it will be passed to your function.

TLS is not supported (but contributions are welcome).

To make an asynchronous request, pass the X-tinyFaaS-Async header with any value. An asynchronous request means the client will receive a 202 response code immediately and no function results will be sent back.

curl --header "X-tinyFaaS-Async: true" "http://localhost:8000/sieve"

gRPC

To use the gRPC endpoint, compile the tinyfaas protocol buffer (included in ./pkg/grpc/tinyfaas) for your programming language and import it into your application. We already provide compiled versions for Go and Python in that directory. Specify the tinyFaaS host and port (default is 9000) for the GRPC endpoint and use the Request function with the functionIdentifier being your function's name and the data field including data in any form you want.

Removing tinyFaaS

When you stop the management service with SIGINT (Ctrl+C), the reverse proxy and all function handlers should be stopped. You can also use:

make clean

OR

docker rm -f $$(docker ps -a -q --filter label=tinyFaaS)
docker network rm $$(docker network ls -q --filter label=tinyFaaS)
docker rmi $$(docker image ls -q --filter label=tinyFaaS)
rm -rf ./tmp

Specifying Ports

By default, tinyFaaS will use the following ports:

Port	Protocol	Description
8080	TCP	Management Service
5683	UDP	CoAP Endpoint
8000	TCP	HTTP Endpoint
9000	TCP	GRPC Endpoint

To change the port of the management service, change the port binding in the docker run command.

To change or deactivate the endpoints of tinyFaaS, you can use the COAP_PORT, HTTP_PORT, and GRPC_PORT environment variables, which must be passed to the management service Docker container. Specify -1 to deactivate a specific endpoint. For example, to use 6000 as the port for the CoAP and deactivate GRPC, run the management service with this command:

docker run --env COAP_PORT=6000 --env GRPC_PORT=-1 -v /var/run/docker.sock:/var/run/docker.sock -p 8080:8080 --name tinyfaas-mgmt -d tinyfaas-mgmt tinyfaas-mgmt