Write a test script that builds all Gentoo packages in the cloud

[rui314]

HPC Engineering at AWS generously donated us US$5000/yr AWS credits. With this much AWS credits, I want to write a test script that fires up bunch of EC2 spot instances and build all Gentoo packages with/without mold in parallel.

I'm currently doing the same thing on my local machine, and even though the machine is very high-end (64-core AMD Threadripper), the test takes a few days. I believe running it in cloud in parallel should shorten its time to an hour or shorter. It'll probably cost ~$200 for each run, so we can't run it on every commit for example, but that's cheap enough to run it on every release.

AWS provides ARM64 machines with their Graviton processor. So, once we write that script, we can run the same tests for ARM64 as well.

I'm no expert of AWS, so I have very little idea how to do this though. Maybe AWS Batch (https://aws.amazon.com/batch) suits best to this kind of task? It needs investigation.