Migrating to 2.3

Tako 2.3.0 removes the outbound HTTP client, adds W3C WebTransport and stable streaming gRPC, and brings every transport to Compio. Most applications only need the first section. See the release notes for the complete list.

The outbound HTTP client is gone

The tako::client module (TakoClient, TakoTlsClient, V2Client) and the client and native-certs features were removed. A build that still enables them fails with an unknown-feature error. Use a dedicated client instead: reqwest for async code or ureq for blocking code.

WebTransport

The webtransport feature now serves W3C WebTransport sessions on the HTTP/3 server, on both runtimes, and browsers can connect to it. A session starts as a CONNECT route that takes the WebTransport extractor; see WebTransport.

• webtransport now enables http3.
• With webtransport, QUIC datagrams are always on; ServerConfig::h3_enable_datagrams = false no longer turns them off.
• RawQuicSession and serve_webtransport are unchanged and stay Tokio-only. The raw QUIC example moved from examples/webtransport to examples/raw-quic; examples/webtransport is now a browser demo.

gRPC

• GrpcServerStream has a new public deadline field. A struct literal needs deadline: None; GrpcServerStream::new(stream) is unaffected.
• The first Err item of a GrpcServerStream ends the call, and later items are no longer sent. Messages that are ready together share one HTTP/2 DATA frame.
• A successful unary reply sends grpc-status in the HTTP/2 trailers instead of the response headers. grpc-go based clients, including grpcurl, rejected the old replies with server closed the stream without sending trailers.
• GrpcRequest reads only as far as the first message, capped at MAX_GRPC_MESSAGE_SIZE, instead of buffering the whole request body.
• New: the Option<GrpcDeadline> extractor and with_deadline, Stream for GrpcClientStream and GrpcBidi, GrpcBidi::respond, From<GrpcError> for GrpcStatus, and GrpcStatus as a responder. See gRPC.

Compio

h2c, Unix sockets, PROXY protocol, HTTP/3, and WebTransport now run on Compio. CompioServer has the same try_spawn_h2c, try_spawn_unix_http, try_spawn_proxy_protocol, and try_spawn_h3 methods as Server, and tako::server_unix and tako::proxy_protocol are available with compio. UnixPeerAddr moved to tako::conn_info and is still re-exported from tako::server_unix.

build_rustls_server_config now installs aws-lc-rs as the process-wide rustls provider when none is installed. Builds that compile both ring and aws-lc-rs, for example with http3, no longer panic at startup.