lamby VS buildkit

AWS Serverless Hero Ken Collins maintains a very popular Rails-Lambda package. After some discussion, he added the capability to track Proactive Initializations and came to a similar conclusion - in his case after a 3-day test using Ruby with a custom runtime, 80% of initializations were proactive:

This means the Monitoring with CloudWatch is just half the picture. But how much is your application potentially benefiting from proactive inits? Since Lamby v5.1.0, you can now find out easily using CloudWatch Metrics. To turn metrics on, enable the config like so:

After years of smashing Cloud & Rails together, I've come up with an idea. Better than an idea, a working specification! One where us Rails & Lambda enthusiasts can once again "console into" our "servers" and execute CLI tasks like migrations or interact via our beloved IRB friend, the Rails console. Today, I would like to present, the Lambda Console project. An open specification proposal for any AWS Lambda runtime to adopt.

> Does this mean you have a cron job just pinging the serverless function every 3 minutes? I'm curious how much this adds on to your costs. It means that the whole "don't pay for non-usage" thing is not quite true, but maybe it's still significantly cheaper than running an EC2 instance or whatnot. I'm curious about the cost calculation here.

Yes, specifically it kicks off a Lambda function that does a parallel GET to our website at a special endpoint that has a 100ms "wait" and basic DB call. This keeps the lambda process alive/in-memory.

To keep a function alive costs ~125ms (100ms wait + 25ms full func roundtrip). every 3 minutes. ~0.041% of 1x CPU time. Our website server costs are tiny and lower for Staging and UAT. Benefit - can scale to 1000x (AWS Limit) servers at the speed of your cold start time.

> Another thing I'm curious about, since you have a container-based deployment, did you compare with Fargate?

Yes we use Fargate for our core product which is built in Rails before containers could be deployed in Lambda. Rails works fine on Lambda[0] but the transition cost wasn't worth it for us. Fargate is great, but as you point out it is expensive if your application isn't a user heavy one like ours. To be highly available, we always have a minimum of 2 online but we're a b2b application so our night usage, 10pm-6am is zero. But I have 2 machines just sitting there. This is why i love Lambda >> Fargate.

Also, scalaing Fargate machines is slow if you get a traffic spike.

[0] https://github.com/rails-lambda/lamby

If you are curious to learn more about how Rails & Lambda work together, check out our Lamby project. The architecture of Lambda Containers works so well with Rails since our framework distills everything from HTTP, Jobs, Events, & WebSocket connections down to amazing CMD Docker contract. The architecture above at the proxy layer was easy to build and connect up to our single delegate function, Lamby.cmd. Shown below.

Today I am happy to announce that Lamby (Simple Rails & AWS Lambda Integration using Rack) now demonstrates just how easy it is to use multi-platform arm64 images on AWS Lambda. If this sounds interesting to you, jump right into our Quick Start guide and deploy a new Rails 7 on Ruby 3.2 Ubuntu image to see it for yourself.

(I have not actually used this myself). The folks over at CustomInk maintain Lamby, a project to run Rails in a quickly-bootable Lambda environment. Might be worth checking out, if you otherwise do enjoy working with Rails: https://lamby.custominktech.com

In any case you can try out https://github.com/customink/lamby which is a gem responsible to allow to run a ror app native on aws lambda.

> We are uding docker-in-docker at the moment

You can also run a "less privileged" container with all the features of Docker by using rootless buildkit in Kubernetes. Here are some examples:

https://github.com/moby/buildkit/tree/master/examples/kubern...

https://github.com/moby/buildkit/blob/master/examples/kubern...

It's also possible to run dedicated buildkitd workers and connect to them remotely.

- BuildOp evaluates its input as additional LLB operations to add to the graph to allow for dynamic build graphs (also unused in the Dockerfile frontend)

With the Dockerfile Explorer, we run the Dockerfile frontend[1] that BuildKit uses inside of WASM to parse and produce the LLB output locally in your browser. We then embed the Monaco Editor so that you can change your Dockerfile to see how it impacts the LLB output that BuildKit will use to build your Docker image.

You can see a quick video and read more details on how it all works here: https://depot.dev/blog/dockerfile-explorer.

We'd love any feedback or ideas folks would like around this type of tool!

[0] https://github.com/moby/buildkit#exploring-llb

Now since Kubernetes works off of containerd I'll be taking a different approach on handling container builds by using nerdctl and the buildkit that comes bundled with it. I'll do this on the amd64 control plane node since it's beefier than my Raspberry Pi workers for handling builds and build related services. Go ahead and download and unpack the latest nerdctl release as of writing (make sure to check the release page in case there's a new one):

There's a 2-year-old moby/buildkit GitHub issue about frequent build cache misses when using the BuildKit docker-container driver and multi-stage builds. Anyone else in this sub run into this problem and/or have reasonable workarounds? It seems like something that should come up pretty often.

A couple months ago I encountered a bug in buildkit - when enabling OpenTelemetry tracing, we got occasional panics. With a bit of investigation, we found the cause, fixed and tested in our fork and internal deployments, and pushed to upstream.

I do some search in the internet and there seems to be no good solution, so I just create a feature request: https://github.com/moby/buildkit/issues/3859

Yeah, only Linux containers at the moment, BuildKit is the way we are constructing pipelines and doing caching. Split on if we will support non-linux hosts, but definitely want to find a good solution to not doing Docker-in-Docker.

Relevant issues are https://github.com/moby/buildkit/issues/3011 and https://github.com/moby/buildkit/issues/1512.