httpcaddyfile: Configure servers via global options (#3836)

* httpcaddyfile: First pass at implementing server options

* httpcaddyfile: Add listener wrapper support

* httpcaddyfile: Sort sbaddrs to make adapt output more deterministic

* httpcaddyfile: Add server options adapt tests

* httpcaddyfile: Windows line endings lol

* caddytest: More windows line endings lol (sorry Matt)

* Update caddyconfig/httpcaddyfile/serveroptions.go

Co-authored-by: Matt Holt <[email protected]>

* httpcaddyfile: Reword listener address "matcher"

* Apply suggestions from code review

Co-authored-by: Matt Holt <[email protected]>

* httpcaddyfile: Deprecate experimental_http3 option (moved to servers)

* httpcaddyfile: Remove validation step, no longer needed

Co-authored-by: Matt Holt <[email protected]>

1 files changed, 235 insertions, 0 deletions

diff --git a/caddyconfig/httpcaddyfile/serveroptions.go b/caddyconfig/httpcaddyfile/serveroptions.go
new file mode 100644
index 000000000..38fa0f155
--- /dev/null
+++ b/caddyconfig/httpcaddyfile/serveroptions.go
@@ -0,0 +1,235 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httpcaddyfile
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig"
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"github.com/dustin/go-humanize"
+)
+
+// serverOptions collects server config overrides parsed from Caddyfile global options
+type serverOptions struct {
+	// If set, will only apply these options to servers that contain a
+	// listener address that matches exactly. If empty, will apply to all
+	// servers that were not already matched by another serverOptions.
+	ListenerAddress string
+
+	// These will all map 1:1 to the caddyhttp.Server struct
+	ListenerWrappersRaw []json.RawMessage
+	ReadTimeout         caddy.Duration
+	ReadHeaderTimeout   caddy.Duration
+	WriteTimeout        caddy.Duration
+	IdleTimeout         caddy.Duration
+	MaxHeaderBytes      int
+	AllowH2C            bool
+	ExperimentalHTTP3   bool
+	StrictSNIHost       *bool
+}
+
+func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (interface{}, error) {
+	serverOpts := serverOptions{}
+	for d.Next() {
+		if d.NextArg() {
+			serverOpts.ListenerAddress = d.Val()
+			if d.NextArg() {
+				return nil, d.ArgErr()
+			}
+		}
+		for nesting := d.Nesting(); d.NextBlock(nesting); {
+			switch d.Val() {
+			case "listener_wrappers":
+				for nesting := d.Nesting(); d.NextBlock(nesting); {
+					mod, err := caddy.GetModule("caddy.listeners." + d.Val())
+					if err != nil {
+						return nil, fmt.Errorf("finding listener module '%s': %v", d.Val(), err)
+					}
+					unm, ok := mod.New().(caddyfile.Unmarshaler)
+					if !ok {
+						return nil, fmt.Errorf("listener module '%s' is not a Caddyfile unmarshaler", mod)
+					}
+					err = unm.UnmarshalCaddyfile(d.NewFromNextSegment())
+					if err != nil {
+						return nil, err
+					}
+					listenerWrapper, ok := unm.(caddy.ListenerWrapper)
+					if !ok {
+						return nil, fmt.Errorf("module %s is not a listener wrapper", mod)
+					}
+					jsonListenerWrapper := caddyconfig.JSONModuleObject(
+						listenerWrapper,
+						"wrapper",
+						listenerWrapper.(caddy.Module).CaddyModule().ID.Name(),
+						nil,
+					)
+					serverOpts.ListenerWrappersRaw = append(serverOpts.ListenerWrappersRaw, jsonListenerWrapper)
+				}
+
+			case "timeouts":
+				for nesting := d.Nesting(); d.NextBlock(nesting); {
+					switch d.Val() {
+					case "read_body":
+						if !d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						dur, err := caddy.ParseDuration(d.Val())
+						if err != nil {
+							return nil, d.Errf("parsing read_body timeout duration: %v", err)
+						}
+						serverOpts.ReadTimeout = caddy.Duration(dur)
+
+					case "read_header":
+						if !d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						dur, err := caddy.ParseDuration(d.Val())
+						if err != nil {
+							return nil, d.Errf("parsing read_header timeout duration: %v", err)
+						}
+						serverOpts.ReadHeaderTimeout = caddy.Duration(dur)
+
+					case "write":
+						if !d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						dur, err := caddy.ParseDuration(d.Val())
+						if err != nil {
+							return nil, d.Errf("parsing write timeout duration: %v", err)
+						}
+						serverOpts.WriteTimeout = caddy.Duration(dur)
+
+					case "idle":
+						if !d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						dur, err := caddy.ParseDuration(d.Val())
+						if err != nil {
+							return nil, d.Errf("parsing idle timeout duration: %v", err)
+						}
+						serverOpts.IdleTimeout = caddy.Duration(dur)
+
+					default:
+						return nil, d.Errf("unrecognized timeouts option '%s'", d.Val())
+					}
+				}
+
+			case "max_header_size":
+				var sizeStr string
+				if !d.AllArgs(&sizeStr) {
+					return nil, d.ArgErr()
+				}
+				size, err := humanize.ParseBytes(sizeStr)
+				if err != nil {
+					return nil, d.Errf("parsing max_header_size: %v", err)
+				}
+				serverOpts.MaxHeaderBytes = int(size)
+
+			case "protocol":
+				for nesting := d.Nesting(); d.NextBlock(nesting); {
+					switch d.Val() {
+					case "allow_h2c":
+						if d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						serverOpts.AllowH2C = true
+
+					case "experimental_http3":
+						if d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						serverOpts.ExperimentalHTTP3 = true
+
+					case "strict_sni_host":
+						if d.NextArg() {
+							return nil, d.ArgErr()
+						}
+						trueBool := true
+						serverOpts.StrictSNIHost = &trueBool
+
+					default:
+						return nil, d.Errf("unrecognized protocol option '%s'", d.Val())
+					}
+				}
+
+			default:
+				return nil, d.Errf("unrecognized servers option '%s'", d.Val())
+			}
+		}
+	}
+	return serverOpts, nil
+}
+
+// applyServerOptions sets the server options on the appropriate servers
+func applyServerOptions(
+	servers map[string]*caddyhttp.Server,
+	options map[string]interface{},
+	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
+	}
+
+	for _, server := range servers {
+		// find the options that apply to this server
+		opts := func() *serverOptions {
+			for _, entry := range serverOpts {
+				if entry.ListenerAddress == "" {
+					return &entry
+				}
+				for _, listener := range server.Listen {
+					if entry.ListenerAddress == listener {
+						return &entry
+					}
+				}
+			}
+			return nil
+		}()
+
+		// if none apply, then move to the next server
+		if opts == nil {
+			continue
+		}
+
+		// set all the options
+		server.ListenerWrappersRaw = opts.ListenerWrappersRaw
+		server.ReadTimeout = opts.ReadTimeout
+		server.ReadHeaderTimeout = opts.ReadHeaderTimeout
+		server.WriteTimeout = opts.WriteTimeout
+		server.IdleTimeout = opts.IdleTimeout
+		server.MaxHeaderBytes = opts.MaxHeaderBytes
+		server.AllowH2C = opts.AllowH2C
+		server.ExperimentalHTTP3 = opts.ExperimentalHTTP3
+		server.StrictSNIHost = opts.StrictSNIHost
+	}
+
+	return nil
+}