OpenFaaS:

OpenFaaS is a function as a service project that can be self-hosted, much like AWS Lambda or Google Functions. Essentially, instead of writing a full project that does various things, you write and maintain functions instead. OpenFaaS can be deployed with Docker Swarm, Kubernetes, and OpenShift.

OpenFaaS documentation is pretty clean and easy to understand. To use it, you need either Docker Swarm, Kubernetes, or OpenShift. Once you deploy OpenFaaS, you need to create a function and deploy it. There are several ways to supply data to the function, one of them is via http requests.

You can use function in sync or async way, without modifying any code at all. You just modify the URL you're sending the http requests too. In addition to that, OpenFaaS will do scaling on its own. If you're using a function a lot and OpenFaaS will spin up containers for that specific function automatically. It's also possible to utilize ci/cd with OpenFaaS to ensure that deploying changes to functions is easy and quick.

I've been mainly experimenting with OpenFaaS on Vultr but it's also possible to play with it in Docker Playground.

Infosec use cases:

I looked through some of my past projects and I can see myself using OpenFaaS if I were to rewrite them. For example, file analysis. It is possible to combine OpenFaaS with other technologies such as Redis (to keep track of operations) and Minio (to allow download/upload of files/artifacts inside of functions) to analyze malicious files or extract metadata from files. In addition to this, you can also implement machine learning and analyze features of a bunch of PE files in a function and return info about if they are malicious or not.

Another use case is analyzing phishing links. I wrote a golang project that takes links from phishtank and splits them into more URLs recursively and checks each URL to see if there is an open directory. It's possible to completely implement this with OpenFaaS. For example, you can send phishtank data to OpenFaaS function every 8 hours and split each link into multiple URLs, send URLs to another function to detect open directory, finally send the URLs that have open directory to another function that downloads files (this would be phishing kit zip files in most cases) from the open directory.

Log analysis or enrichment is another use case. For example, if you were receiving logs about remote sign-ins, you could send the logs in batches or individually to a function or functions to extract IP and do log enrichment based on API lookups for the IP or finding geolocation.

OpenFaaS can be useful for doing analysis of forensic artifacts. If you're working an incident and need to analyze artifacts from hundreds of computers, you can collect the evidence, throw it in Minio, have a bunch of functions to analyze the evidence, maybe even send the output to another set of functions for enrichment before sending the final evidence to storage or SIEM.

I discovered the OpenFaaS project earlier this month and it has been fun to play with and I can see myself using it a lot. Being able to deploy and maintain specific functions instead of a huge application is much easier for me. Also not having to write code that's threaded and OpenFaaS doing automated scaling is very nice.

Links:

https://www.openfaas.com/
https://docs.openfaas.com/deployment/
https://docs.openfaas.com/reference/triggers/
https://docs.openfaas.com/reference/async/
https://docs.openfaas.com/reference/cicd/intro/
https://www.vultr.com/docs/deploying-openfaas-using-docker-swarm
https://docs.openfaas.com/deployment/play-with-docker/
https://redis.io/
https://min.io/
https://www.phishtank.com/
https://blog.alexellis.io/openfaas-storage-for-your-functions/
https://youtu.be/XiagsmRVoNY

https://www.vultr.com/?ref=7127410 (Affiliate link...)