proposal: x/net/http2: add EnableConnectProtocol to Server

[WeidiDeng]

Proposal Details

In this accepted proposal a new field is added to http.HTTP2Config to allow the h2 server to declare Extended Connect support without explicitly importing x/net/http2 package.

However, currently h2 package uses a global debug env http2xconnect to control this setting.

Given that other fields in http.HTTP2Config have a corresponding field in http2.Server, and this config is merged with h2 configurations, I propose we remove http2xconnect debug environmental variable and add a new dedicated field EnableConnectProtocol to control whether extended connect is enabled.

By default this field is false, so websocket connection made by clients still uses h1 upgrade mechanism, thus backward compatible. Extended connect support has to be enabled explicitly by the user.

This proposal only adds a new API, so there is no breaking change.

[gabyhelp]

Related Issues

• proposal: x/net/http2: experiment with Extended CONNECT draft #27244 (closed)
• net/http: add support for SETTINGS_ENABLE_CONNECT_PROTOCOL #53208
• proposal: x/net/websocket: implement support for websockets over HTTP/2 #53209
• net/http: support unencrypted HTTP/2 (h2c) #67816 (closed)
• net/http: do not enable HTTP/2 extended connect by default #71128 (closed)
• proposal: x/net/http2/h2c: deprecate h2c package #72039

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[ianlancetaylor]

CC @neild