caddyhttp: Enable HTTP/3 by default

caddyconfig/httpcaddyfile/serveroptions.go

@@ -39,8 +39,7 @@ type serverOptions struct {
 	WriteTimeout         caddy.Duration
 	IdleTimeout          caddy.Duration
 	MaxHeaderBytes       int
-	AllowH2C             bool
-	ExperimentalHTTP3    bool
+	Protocols            []string
 	StrictSNIHost        *bool
 	ShouldLogCredentials bool
 }
@@ -141,22 +140,51 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (any, error) {
 				}
 				serverOpts.ShouldLogCredentials = true
 
+			case "protocols":
+				protos := d.RemainingArgs()
+				for _, proto := range protos {
+					if proto != "h1" && proto != "h2" && proto != "h2c" && proto != "h3" {
+						return nil, d.Errf("unknown protocol '%s': expected h1, h2, h2c, or h3", proto)
+					}
+					if sliceContains(serverOpts.Protocols, proto) {
+						return nil, d.Errf("protocol %s specified more than once", proto)
+					}
+					serverOpts.Protocols = append(serverOpts.Protocols, proto)
+				}
+				if d.NextBlock(0) {
+					return nil, d.ArgErr()
+				}
+
+			case "strict_sni_host":
+				if d.NextArg() && d.Val() != "insecure_off" && d.Val() != "on" {
+					return nil, d.Errf("strict_sni_host only supports 'on' or 'insecure_off', got '%s'", d.Val())
+				}
+				boolVal := true
+				if d.Val() == "insecure_off" {
+					boolVal = false
+				}
+				serverOpts.StrictSNIHost = &boolVal
+
+			// TODO: DEPRECATED. (August 2022)
 			case "protocol":
+				caddy.Log().Named("caddyfile").Warn("DEPRECATED: protocol sub-option will be removed soon")
+
 				for nesting := d.Nesting(); d.NextBlock(nesting); {
 					switch d.Val() {
 					case "allow_h2c":
-						if d.NextArg() {
-							return nil, d.ArgErr()
-						}
-						serverOpts.AllowH2C = true
+						caddy.Log().Named("caddyfile").Warn("DEPRECATED: allow_h2c will be removed soon; use protocols option instead")
 
-					case "experimental_http3":
 						if d.NextArg() {
 							return nil, d.ArgErr()
 						}
-						serverOpts.ExperimentalHTTP3 = true
+						if sliceContains(serverOpts.Protocols, "h2c") {
+							return nil, d.Errf("protocol h2c already specified")
+						}
+						serverOpts.Protocols = append(serverOpts.Protocols, "h2c")
 
 					case "strict_sni_host":
+						caddy.Log().Named("caddyfile").Warn("DEPRECATED: protocol > strict_sni_host in this position will be removed soon; move up to the servers block instead")
+
 						if d.NextArg() && d.Val() != "insecure_off" && d.Val() != "on" {
 							return nil, d.Errf("strict_sni_host only supports 'on' or 'insecure_off', got '%s'", d.Val())
 						}
@@ -185,17 +213,6 @@ func applyServerOptions(
 	options map[string]any,
 	warnings *[]caddyconfig.Warning,
 ) error {
-	// If experimental HTTP/3 is enabled, enable it on each server.
-	// We already know there won't be a conflict with serverOptions because
-	// we validated earlier that "experimental_http3" cannot be set at the same
-	// time as "servers"
-	if enableH3, ok := options["experimental_http3"].(bool); ok && enableH3 {
-		*warnings = append(*warnings, caddyconfig.Warning{Message: "the 'experimental_http3' global option is deprecated, please use the 'servers > protocol > experimental_http3' option instead"})
-		for _, srv := range servers {
-			srv.ExperimentalHTTP3 = true
-		}
-	}
-
 	serverOpts, ok := options["servers"].([]serverOptions)
 	if !ok {
 		return nil
@@ -229,8 +246,7 @@ func applyServerOptions(
 		server.WriteTimeout = opts.WriteTimeout
 		server.IdleTimeout = opts.IdleTimeout
 		server.MaxHeaderBytes = opts.MaxHeaderBytes
-		server.AllowH2C = opts.AllowH2C
-		server.ExperimentalHTTP3 = opts.ExperimentalHTTP3
+		server.Protocols = opts.Protocols
 		server.StrictSNIHost = opts.StrictSNIHost
 		if opts.ShouldLogCredentials {
 			if server.Logs == nil {

caddytest/integration/caddyfile_adapt/global_server_options_single.txt

@@ -12,11 +12,8 @@
 		}
 		max_header_size 100MB
 		log_credentials
-		protocol {
-			allow_h2c
-			experimental_http3
-			strict_sni_host
-		}
+		strict_sni_host
+		protocols h1 h2 h2c h3
 	}
 }
 
@@ -61,8 +58,12 @@ foo.com {
 					"logs": {
 						"should_log_credentials": true
 					},
-					"experimental_http3": true,
-					"allow_h2c": true
+					"protocols": [
+						"h1",
+						"h2",
+						"h2c",
+						"h3"
+					]
 				}
 			}
 		}

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/klauspost/compress v1.15.9
 	github.com/klauspost/cpuid/v2 v2.1.0
-	github.com/lucas-clemente/quic-go v0.28.1
+	github.com/lucas-clemente/quic-go v0.28.2-0.20220813150001-9957668d4301
 	github.com/mholt/acmez v1.0.4
 	github.com/prometheus/client_golang v1.12.2
 	github.com/smallstep/certificates v0.21.0
@@ -37,6 +37,11 @@ require (
 	gopkg.in/yaml.v3 v3.0.1
 )
 
+require (
+	github.com/golang/mock v1.6.0 // indirect
+	golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e // indirect
+)
+
 require (
 	filippo.io/edwards25519 v1.0.0-rc.1 // indirect
 	github.com/AndreasBriese/bbloom v0.0.0-20190825152654-46b345b51c96 // indirect
@@ -47,7 +52,6 @@ require (
 	github.com/cenkalti/backoff/v4 v4.1.2 // indirect
 	github.com/cespare/xxhash v1.1.0 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
-	github.com/cheekybits/genny v1.0.0 // indirect
 	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
 	github.com/dgraph-io/badger v1.6.2 // indirect
@@ -79,10 +83,8 @@ require (
 	github.com/libdns/libdns v0.2.1 // indirect
 	github.com/manifoldco/promptui v0.9.0 // indirect
 	github.com/marten-seemann/qpack v0.2.1 // indirect
-	github.com/marten-seemann/qtls-go1-16 v0.1.5 // indirect
-	github.com/marten-seemann/qtls-go1-17 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-18 v0.1.2 // indirect
-	github.com/marten-seemann/qtls-go1-19 v0.1.0-beta.1 // indirect
+	github.com/marten-seemann/qtls-go1-19 v0.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.8 // indirect
 	github.com/mattn/go-isatty v0.0.13 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
@@ -119,10 +121,10 @@ require (
 	go.step.sm/linkedca v0.16.1 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
-	golang.org/x/mod v0.4.2 // indirect
+	golang.org/x/mod v0.6.0-dev.0.20220106191415-9b9b3d81d5e3 // indirect
 	golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10
 	golang.org/x/text v0.3.8-0.20211004125949-5bd84dd9b33b // indirect
-	golang.org/x/tools v0.1.7 // indirect
+	golang.org/x/tools v0.1.10 // indirect
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	google.golang.org/grpc v1.46.0 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect