feat: add support for souin

[JacquesDurand]

Q	A
Branch?	main
Tickets	#1947
License	MIT
Doc PR	api-platform/docs#1720

Hi !
This is a first attempt to integrate Souin, a HTTP Cache handler that can be built as a module for Caddy. This is still a work in progress.
It contains a seemingly minimal caddy configuration, as well as some configuration for api-platform to handle cache and invalidation.

Note: composer.lock is here as api-platform/core contains necessary bug fixes concerning the SurrogateKeyPurger class that are not yet integrated in the distribution (coming in api-platform/core:3.1.2 if I am not mistaken. The updated composer.lock won't be needed anymore soon.

What works:

• xcaddy build in Dockerfile
• caching through Surrogate-keys:
  

What I am not sure about:

• Invalidation:
  With the current configuration, the SouinPurger is called on postFlush when an ApiResource is modified (PATCH request for instance), and the PURGE request is made to the souin API (https://localhost/souin-api/souin by default) with the correct headers.

Here is an exemple of what caddy receives (and responds):

Nevertheless, requesting GET /greetings after said PATCH request still hits the cache

What still needs to be figured out:

• Souin security, and access to its API only with JWT

[JacquesDurand]

Note: after a discussion with souin maintainer (cf here), Surrogate Keys invalidation on postFlush has been resolved

[darkweak]

By the way, FYI the JWT authentication by Souin itself will be deprecated on the next minor release I'm working on.

[francislavoie]

The braces and * matcher are not necessary.

Suggested change

	cache * {
	}
	cache

[francislavoie]

spaces -> tabs

Suggested change

	--with github.com/darkweak/souin/plugins/caddy
	--with github.com/darkweak/souin/plugins/caddy

[darkweak]

Ping @soyuka

[soyuka]

what about http-tests/cache-tests#112 ?

If it works I'm 👍 on merging this, @dunglas ?

[darkweak]

That’s almost done, I have some points to discuss about the expectations.

[darkweak]

I think we can merge that while talking about the default behavior when no Cache-Control header given. They expect to not cache the response but the RFC doesn't give informations on that. (cc @mnot)

[dunglas]

LGTM. Is it possible to simplify the Caddy config and just use the defaults provided by Souin?

[darkweak]

The Caddyfile could just set the cache directive because by default it stores for 2 minutes. @JacquesDurand

[darkweak]

Suggested change

	allowed_http_verbs GET POST
	api {
	souin
	}
	cdn {
	dynamic
	provider default
	}
	ttl 1000s
	timeout {
	backend 10s
	cache 100ms
	}