## Issue Addressed
Fix OOMs caused by too many concurrent tests. The runner machine is currently liable to run `32 * 5 = 160` tests in parallel. If each test uses say 300MB max, this is 48GB of RAM!
## Proposed Changes
Reduce the number of threads per runner job to 8. This should cap the memory at 4x lower than the current limit, i.e. around 12GB. If we continue to run out of RAM, we should consider more sophisticated limits.
Attempting to improve our CI speeds as its recently been a pain point.
Major changes:
- Use a github action to pull stable/nightly rust rather than building it each run
- Shift test suite to `nexttest` https://github.com/nextest-rs/nextest for CI
UPDATE:
So I've iterated on some changes, and although I think its still not optimal I think this is a good base to start from. Some extra things in this PR:
- Shifted where we pull rust from. We're now using this thing: https://github.com/moonrepo/setup-rust . It's got some interesting cache's built in, but was not seeing the gains that Jimmy managed to get. In either case tho, it can pull rust, cargofmt, clippy, cargo nexttest all in < 5s. So I think it's worthwhile.
- I've grouped a few of the check-like tests into a single test called `code-test`. Although we were using github runners in parallel which may be faster, it just seems wasteful. There were like 4-5 tests, where we would pull lighthouse, compile it, then run an action, like clippy, cargo-audit or fmt. I've grouped these into a single action, so we only compile lighthouse once, then in each step we run the checks. This avoids compiling lighthouse like 5 times.
- Ive made doppelganger tests run on our local machines to avoid pulling foundry, building and making lcli which are all now baked into the images.
- We have sccache and do not incremental compile lighthouse
Misc bonus things:
- Cargo update
- Fix web3 signer openssl keys which is required after a cargo update
- Use mock_instant in an LRU cache test to avoid non-deterministic test
- Remove race condition in building web3signer tests
There's still some things we could improve on. Such as downloading the EF tests every run and the web3-signer binary, but I've left these to be out of scope of this PR. I think the above are meaningful improvements.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: antondlr <anton@delaruelle.net>
