x/net/http2: deprecate Transport and Server

[neild]

I propose to deprecate the x/net/http2 Transport and Server types.

Every supported feature of these types is available through public APIs in the net/http package. There is no longer any need for users to use these types, and we can now deprecate them.

Specifically, I propose deprecating:

• The Transport and Server types (and implicitly their fields and methods). Users who need an HTTP/2-only client or server can configure the net/http Transport or Server to use only HTTP/2.
• The ConfigureServer, ConfigureTransport, and ConfigureTransports functions. These functions were historically used to configure HTTP/2 behaviors of net/http clients and servers, but net/http supports configuring these settings directly
• The ClientConn and ClientConnState types, which have been superseded by net/http.ClientConn.
• RoundTripOpt and ServeConnOpts, which are options types only used by now-deprecated Transport and Server methods.

This proposal is a superset of #77695, which proposes deprecating only the client connection API.

[gabyhelp]

Related Issues

• proposal: x/net/http2: deprecate ClientConnPool #77695
• proposal: x/net/http2/h2c: deprecate h2c package #72039
• x/net/http2: deprecate WriteScheduler #67817 (closed)
• proposal: net/http/httputil/v2: remove ClientConn, ServerConn #7907
• net/http: move HTTP/2 into std #67810
• x/net/http2: move frame operations to x/net/http2/http2frame #67819
• net/http: HTTP version selection API #67814 (closed)
• x/net/http2/h2c: uses obsolete upgrade mechanism #63565 (closed)
• net/http: HTTP/2 configuration API #67813 (closed)

Related Discussions

• net/http: move HTTP/2 into the standard library

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

[andybalholm]

In github.com/andybalholm/redwood (an HTTP proxy), I use the http2 package directly for low-level control. I've found that it works best to have a one-to-one mapping of connections from the client and connections to the origin servers, with matching HTTP versions. So I want to make sure that equivalent functionality will still be available after rolling the http2 package into stdlib.

[neild]

Is there specific functionality that you're relying on that isn't available in net/http?

For client connection management, net/http's Transport.NewClientConn (new in Go 1.26) should do everything the x/net/http2 version does and more.

[andybalholm]

I was missing some things, but it looks like Go 1.26 filled in the gaps: andybalholm/redwood@52675de

[aclements]

This proposal has been added to the active column of the proposals project
and will now be reviewed at the weekly proposal review meetings.
— aclements for the proposal review group

[aclements]

Based on the discussion above, this proposal seems like a likely accept.
— aclements for the proposal review group

The proposal is given in #78064 (comment)