feat(awc): allow to set a specific sni host on the request

[joelwurtz]

PR Type

Feature

PR Checklist

• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• A changelog entry has been made for the appropriate packages.
• Format code with the latest stable rustfmt.
• (Team) Label with affected crates and semver status.

Overview

This PR allow client to set a specific sni host for a request, this can be useful if you want to connect to a specific hostname, but do SSL validation on another one

In order to do that some thing have been changed :

• Uri is no longer cloned during connection, instead a specific object is created with only wanted information, it may be better as we don't need all uri information in the connection (only hostname, port and if it should use tls most of the time), so this should also reduce memory consumption on certain case.
• A new object is used for tcp / tls connection : HostnameWithSni (can be changed to another name), basically it's the host with the optional sni host and a state (to know which host to use given the connector: we use hostname during tcp, for dns resolution if needed, we use sni_host if available during tls connection for server name)
• The pool now use the connect object for its key of pooled connection, i believe the old way was not adequate (did not do test, since it was only relying on the authority of the uri, if you pass a specific local address by example, after a first request it would not have use the existing pool, and i believe it should not in this case ?)

There may be better implementation on some point, as i have done what it's the most pragmatic way as a first step, will be happy to fix those if you have some inputs.

[joelwurtz]

there may be a better way, but a lot of code need to be updated and was not sure about the correct / standard thing to do here, this is a pragmatic way of doing it, but if you have an idea on how to avoid this will be glad to hear.