fix: no-op math.randomseed() once called by Kong

[thibaultcha]

Summary

This replaces #1554, since the improved seeding technique was not an
appropriate fix. To this point, I do not think it is worth investing in such a
complex seeding technique as the root of the issue really was the
continuous use of math.randomseed() by one of Lapis' utilities.

Changes

• Disable (or rather, no-op) math.randomseed() to prevent
  third-party modules from overriding our correct seed (many modules
  make a wrong usage of math.randomseed() by calling it multiple times
  or do not use unique seed for Nginx workers.
• Bump lua-resty-jit-uuid version to include uuid.seed() changes
• Shorten the name of some of our cached variables

---

Update:

fix: patch math.randomseed() to prevent invalid calls …
Patch math.random to prevent it from being called by another context
than init_worker, and especially to prevent it from being called
multiple times. It is being patched very early in Kong's runtime so
we're sure no other module has time to cache the original math.random
function.

• implement a globalpatches.lua module for modifying _G.
• seed in init_worker with math.randomseed

[Tieske]

isn't this too late? it replaces it when seeding, so any other module might have cached the original function and still call it.

So store the original in an upvalue, and replace upon module loading? and then even make sure it is loaded first...

[Tieske]

btw maybe cleaner to create a new module globalpatches or something similar. And just replace math.randomseed with the one from lua-resty-jit-uuid.

Or even update lua-resty-jit-uuid to make its randomseed signature like randomseed(seed, cmd) where cmd could be either string 'patch' (patches the global randomseed), or 'force' (forces a new randomseed anyway, to be called from worker_init).

[thibaultcha]

Patch updated

[thibaultcha]

not a typo but will also include pid

[Tieske]

I like it in a new module for global patches, stands out cleanly.

lgtm!