fix: fix wasm middleware guest module instance memory leak issue

[ttys3]

fixup guest module instance creation without guest module free caused memory leak

related issue: traefik/traefik#11119

related PR: traefik#2

cc @juliens

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since this implementation make usage of sync.Pool

we must call Close() method of the module when the sync.Pool object got GC ed.

without call Close() to releases resources allocated for this Module, the memory will leak

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related PR

see also traefik/traefik#11151 which fixup the wasm plugin memory leak when dynamic config loading ( which cause all related route middleware recreation), we have to call nethttp.middleware.Close() (which will call handler.middleware.Close() -> wazero.Runtime.Close() ) to free the memory

[ttys3]

imports style fixed, please approve CI actions

[jcchavezs]

Thanks for this @ttys3, any chance you can port the benchmarks into this PR?

[ttys3]

Thanks for this @ttys3, any chance you can port the benchmarks into this PR?

I have all things to reproduce and verify the leak issue and the PR fixed the issue in the repo: https://github.com/ttys3/traefik-wasm-plugin-memory-leak-demo/

but I do not know how to port them to this.

any advice ? @jcchavezs

[jcchavezs]

I think the main issue comes from traefik/traefik#11119 (comment)

[ttys3]

I think the main issue comes from traefik/traefik#11119 (comment)

I think it's just the opposite; that leak is secondary. The main leak is addressed in this PR.

They are two different types of leaks. Although they have similar symptoms, they are not the same issue.