Complex topic :)
This will break if anyone is using e.g. the 'esi' service directly.
If adding the "cache" service in the xml is not required, I'd suggest removing it also, for BC concerns.
Then, what about deprecating the esi and ssi services, and passing the service around using a request parameter instead? It's a scoped service to me, that doesn't fit the container, isn't it?

👍 for deprecation the esi/ssi defintions (and revert adding cache definition).

About

$this->getKernel()->getContainer()->set('cache', $this);
$this->getKernel()->getContainer()->set($this->getSurrogate()->getName(), $this->getSurrogate());

Is this needed, either setting them as request attribute or service =/ I believe @cache will equal @kernel anyway. And @<surrogate-name> equals @kernel->getSurrogate()

Not sure we need to pass anything here =/

edit:
but @esi_listener needs a patch, or indeed, depend on a request param.

@ro0NL right, let's try this way.

Hm.. we can have 2 SurrogateListener's, the HttpCache will only have 1 surrogate.

So we cant deprecate the service really, but we should check for a esi/ssi surrogate from the kernel first. Let me try :)

Something like this :)

Thank you @ro0NL.