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 <mholt@users.noreply.github.com>

* httpcaddyfile: Reword listener address "matcher"

* Apply suggestions from code review

Co-authored-by: Matt Holt <mholt@users.noreply.github.com>

* httpcaddyfile: Deprecate experimental_http3 option (moved to servers)

* httpcaddyfile: Remove validation step, no longer needed

Co-authored-by: Matt Holt <mholt@users.noreply.github.com>

4 files changed, 290 insertions, 13 deletions

diff --git a/caddyconfig/httpcaddyfile/addresses.go b/caddyconfig/httpcaddyfile/addresses.go
index 51411a9..7105320 100644
--- a/caddyconfig/httpcaddyfile/addresses.go
+++ b/caddyconfig/httpcaddyfile/addresses.go
@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"net"
 	"reflect"
+	"sort"
 	"strconv"
 	"strings"
 	"unicode"
@@ -163,6 +164,13 @@ func (st *ServerType) consolidateAddrMappings(addrToServerBlocks map[string][]se
 
 		sbaddrs = append(sbaddrs, a)
 	}
+
+	// sort them by their first address (we know there will always be at least one)
+	// to avoid problems with non-deterministic ordering (makes tests flaky)
+	sort.Slice(sbaddrs, func(i, j int) bool {
+		return sbaddrs[i].addresses[0] < sbaddrs[j].addresses[0]
+	})
+
 	return sbaddrs
 }
 
diff --git a/caddyconfig/httpcaddyfile/httptype.go b/caddyconfig/httpcaddyfile/httptype.go
index 35eab90..e4e40b2 100644
--- a/caddyconfig/httpcaddyfile/httptype.go
+++ b/caddyconfig/httpcaddyfile/httptype.go
@@ -218,13 +218,6 @@ func (st ServerType) Setup(inputServerBlocks []caddyfile.ServerBlock,
 		return nil, warnings, err
 	}
 
-	// if experimental HTTP/3 is enabled, enable it on each server
-	if enableH3, ok := options["experimental_http3"].(bool); ok && enableH3 {
-		for _, srv := range httpApp.Servers {
-			srv.ExperimentalHTTP3 = true
-		}
-	}
-
 	// extract any custom logs, and enforce configured levels
 	var customLogs []namedCustomLog
 	var hasDefaultLog bool
@@ -311,23 +304,54 @@ func (ServerType) evaluateGlobalOptionsBlock(serverBlocks []serverBlock, options
 	}
 
 	for _, segment := range serverBlocks[0].block.Segments {
-		dir := segment.Directive()
+		opt := segment.Directive()
 		var val interface{}
 		var err error
 		disp := caddyfile.NewDispenser(segment)
 
-		dirFunc, ok := registeredGlobalOptions[dir]
+		optFunc, ok := registeredGlobalOptions[opt]
 		if !ok {
 			tkn := segment[0]
-			return nil, fmt.Errorf("%s:%d: unrecognized global option: %s", tkn.File, tkn.Line, dir)
+			return nil, fmt.Errorf("%s:%d: unrecognized global option: %s", tkn.File, tkn.Line, opt)
 		}
 
-		val, err = dirFunc(disp)
+		val, err = optFunc(disp)
 		if err != nil {
-			return nil, fmt.Errorf("parsing caddyfile tokens for '%s': %v", dir, err)
+			return nil, fmt.Errorf("parsing caddyfile tokens for '%s': %v", opt, err)
+		}
+
+		// As a special case, fold multiple "servers" options together
+		// in an array instead of overwriting a possible existing value
+		if opt == "servers" {
+			existingOpts, ok := options[opt].([]serverOptions)
+			if !ok {
+				existingOpts = []serverOptions{}
+			}
+			serverOpts, ok := val.(serverOptions)
+			if !ok {
+				return nil, fmt.Errorf("unexpected type from 'servers' global options")
+			}
+			options[opt] = append(existingOpts, serverOpts)
+			continue
 		}
 
-		options[dir] = val
+		options[opt] = val
+	}
+
+	// If we got "servers" options, we'll sort them by their listener address
+	if serverOpts, ok := options["servers"].([]serverOptions); ok {
+		sort.Slice(serverOpts, func(i, j int) bool {
+			return len(serverOpts[i].ListenerAddress) > len(serverOpts[j].ListenerAddress)
+		})
+
+		// Reject the config if there are duplicate listener address
+		seen := make(map[string]bool)
+		for _, entry := range serverOpts {
+			if _, alreadySeen := seen[entry.ListenerAddress]; alreadySeen {
+				return nil, fmt.Errorf("cannot have 'servers' global options with duplicate listener addresses: %s", entry.ListenerAddress)
+			}
+			seen[entry.ListenerAddress] = true
+		}
 	}
 
 	return serverBlocks[1:], nil
@@ -602,6 +626,11 @@ func (st *ServerType) serversFromPairings(
 		servers[fmt.Sprintf("srv%d", i)] = srv
 	}
 
+	err := applyServerOptions(servers, options, warnings)
+	if err != nil {
+		return nil, err
+	}
+
 	return servers, nil
 }
 
diff --git a/caddyconfig/httpcaddyfile/options.go b/caddyconfig/httpcaddyfile/options.go
index 7d34805..5001974 100644
--- a/caddyconfig/httpcaddyfile/options.go
+++ b/caddyconfig/httpcaddyfile/options.go
@@ -43,6 +43,7 @@ func init() {
 	RegisterGlobalOption("local_certs", parseOptTrue)
 	RegisterGlobalOption("key_type", parseOptSingleString)
 	RegisterGlobalOption("auto_https", parseOptAutoHTTPS)
+	RegisterGlobalOption("servers", parseServerOptions)
 }
 
 func parseOptTrue(d *caddyfile.Dispenser) (interface{}, error) {
@@ -361,3 +362,7 @@ func parseOptAutoHTTPS(d *caddyfile.Dispenser) (interface{}, error) {
 	}
 	return val, nil
 }
+
+func parseServerOptions(d *caddyfile.Dispenser) (interface{}, error) {
+	return unmarshalCaddyfileServerOptions(d)
+}
diff --git a/caddyconfig/httpcaddyfile/serveroptions.go b/caddyconfig/httpcaddyfile/serveroptions.go
new file mode 100644
index 0000000..38fa0f1
--- /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
+}