How to set limits for functions faasd + containerd

[enkov]

Hello!
How can I set limits for functions? I tried this

version: 1.0
provider:
  name: openfaas
  gateway: http://127.0.0.1:8080
functions:
  hello-world:
    lang: python3
    handler: ./hello-world
    image: test/hello-world:latest
    limits:
      memory: 1Mi
    requests:
      memory: 1Mi

And this

version: 1.0
provider:
  name: openfaas
  gateway: http://127.0.0.1:8080
functions:
  hello-world:
    lang: python3
    handler: ./hello-world
    image: test/hello-world:latest
    limits:
      memory: 1m
    requests:
      memory: 1m

And it doesn't work.

[alexellis]

Hi it's not supported at present. A number of features will not be available in faasd.

What's the usecase you have with regards to the limiting and what would you expect to happen if that was exceeded?

[enkov]

Hello!
I want to limit ram of function and if function exceed it, kill function. I thought it would work like in kubernetes, if limit reached OOM killer kills app.
And if I am right containerd can set limits.
Can You tell will it be available some day?

[alexellis]

Once killed are you expecting it to be restarted?

What specific workload are you running right now? Also 1MB of RAM isn't that realistic, so I'm wondering if this is a genuine need or more because that's just what you expected? The answer will help us triage the request

[enkov]

Once killed I expect what function will be restarted and can be called again because there can be different input data.
I want to start users code and want to limit it.
1MB RAM is a test example for testing limits. For the real workload, I will set bigger values for RAM.

[alexellis]

Ok, got it. What are you specifically wanting to use faasd with at the present time?

[enkov]

I need a solution that can run in kubernetes and on baremetal. After some research, I found that openfaas is the best solution because it can be deployed on baremetal with faasd.

[alexellis]

OK I don't think I'm asking correctly or maybe you are not so keen to share - but do you have a use-case, if so what? (languages, usage of it, application, events, other requirements etc?)

[enkov]

My use case is to let users start their scripts for some calculations.
Data for these scripts will come from different sources(database, queue).
And I don't know how good these scripts work with memory and I want to limit them, so one script will not use all available resources.
Most of the scrips will use python3.

[alexellis]

Is this a multi-tenant environment then? I would be very careful of using faasd for that, since it has no isolation or way of blocking a container running as root (at present)

You may prefer openfaas on Kubernetes backed by gVisor or Kata containers. You'll also find the requests/limits there.

But, for anyone landing here: we will look into container limits for faasd. Contributions are welcome :-)

[alexellis]

This code could be of use to us from Michael’s boss project. I can see a way to set a limit, but not sure if “requests” is a containerd or K8s concept. @AkihiroSuda do you know?

https://github.com/crosbymichael/boss/blob/bbbfd63bba42337c0dbfa073a14ac7e8d91bf525/opts/opts.go#L152