Keep type information with placeholders until replacements happen

modules/caddyhttp/celmatcher.go

@@ -86,7 +86,7 @@ func (m *MatchExpression) Provision(_ caddy.Context) error {
 			decls.NewFunction(placeholderFuncName,
 				decls.NewOverload(placeholderFuncName+"_httpRequest_string",
 					[]*exprpb.Type{httpRequestObjectType, decls.String},
-					decls.String)),
+					decls.Any)),
 		),
 		cel.CustomTypeAdapter(celHTTPRequestTypeAdapter{}),
 		ext.Strings(),
@@ -210,7 +210,35 @@ func caddyPlaceholderFunc(lhs, rhs ref.Val) ref.Val {
 	repl := celReq.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
 	val, _ := repl.Get(string(phStr))
 
-	return types.String(val)
+	// TODO: this is... kinda awful and underwhelming, how can we expand CEL's type system more easily?
+	switch v := val.(type) {
+	case string:
+		return types.String(v)
+	case fmt.Stringer:
+		return types.String(v.String())
+	case error:
+		return types.NewErr(v.Error())
+	case int:
+		return types.Int(v)
+	case int32:
+		return types.Int(v)
+	case int64:
+		return types.Int(v)
+	case uint:
+		return types.Int(v)
+	case uint32:
+		return types.Int(v)
+	case uint64:
+		return types.Int(v)
+	case float32:
+		return types.Double(v)
+	case float64:
+		return types.Double(v)
+	case bool:
+		return types.Bool(v)
+	default:
+		return types.String(fmt.Sprintf("%+v", v))
+	}
 }
 
 // Interface guards

modules/caddyhttp/replacer.go

@@ -31,7 +31,7 @@ import (
 )
 
 func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.ResponseWriter) {
-	httpVars := func(key string) (string, bool) {
+	httpVars := func(key string) (interface{}, bool) {
 		if req != nil {
 			// query string parameters
 			if strings.HasPrefix(key, reqURIQueryReplPrefix) {
@@ -62,7 +62,7 @@ func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.Respo
 				}
 			}
 
-			// http.request.tls.
+			// http.request.tls.*
 			if strings.HasPrefix(key, reqTLSReplPrefix) {
 				return getReqTLSReplacement(req, key)
 			}
@@ -182,21 +182,10 @@ func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.Respo
 			if strings.HasPrefix(key, varsReplPrefix) {
 				varName := key[len(varsReplPrefix):]
 				tbl := req.Context().Value(VarsCtxKey).(map[string]interface{})
-				raw, ok := tbl[varName]
-				if !ok {
-					// variables can be dynamic, so always return true
-					// even when it may not be set; treat as empty
-					return "", true
-				}
-				// do our best to convert it to a string efficiently
-				switch val := raw.(type) {
-				case string:
-					return val, true
-				case fmt.Stringer:
-					return val.String(), true
-				default:
-					return fmt.Sprintf("%s", val), true
-				}
+				raw, _ := tbl[varName]
+				// variables can be dynamic, so always return true
+				// even when it may not be set; treat as empty then
+				return raw, true
 			}
 		}
 
@@ -211,19 +200,19 @@ func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.Respo
 			}
 		}
 
-		return "", false
+		return nil, false
 	}
 
 	repl.Map(httpVars)
 }
 
-func getReqTLSReplacement(req *http.Request, key string) (string, bool) {
+func getReqTLSReplacement(req *http.Request, key string) (interface{}, bool) {
 	if req == nil || req.TLS == nil {
-		return "", false
+		return nil, false
 	}
 
 	if len(key) < len(reqTLSReplPrefix) {
-		return "", false
+		return nil, false
 	}
 
 	field := strings.ToLower(key[len(reqTLSReplPrefix):])
@@ -231,20 +220,20 @@ func getReqTLSReplacement(req *http.Request, key string) (string, bool) {
 	if strings.HasPrefix(field, "client.") {
 		cert := getTLSPeerCert(req.TLS)
 		if cert == nil {
-			return "", false
+			return nil, false
 		}
 
 		switch field {
 		case "client.fingerprint":
 			return fmt.Sprintf("%x", sha256.Sum256(cert.Raw)), true
 		case "client.issuer":
-			return cert.Issuer.String(), true
+			return cert.Issuer, true
 		case "client.serial":
-			return fmt.Sprintf("%x", cert.SerialNumber), true
+			return cert.SerialNumber, true
 		case "client.subject":
-			return cert.Subject.String(), true
+			return cert.Subject, true
 		default:
-			return "", false
+			return nil, false
 		}
 	}
 
@@ -254,22 +243,15 @@ func getReqTLSReplacement(req *http.Request, key string) (string, bool) {
 	case "cipher_suite":
 		return tls.CipherSuiteName(req.TLS.CipherSuite), true
 	case "resumed":
-		if req.TLS.DidResume {
-			return "true", true
-		}
-		return "false", true
+		return req.TLS.DidResume, true
 	case "proto":
 		return req.TLS.NegotiatedProtocol, true
 	case "proto_mutual":
-		if req.TLS.NegotiatedProtocolIsMutual {
-			return "true", true
-		}
-		return "false", true
+		return req.TLS.NegotiatedProtocolIsMutual, true
 	case "server_name":
 		return req.TLS.ServerName, true
-	default:
-		return "", false
 	}
+	return nil, false
 }
 
 // getTLSPeerCert retrieves the first peer certificate from a TLS session.

modules/caddyhttp/reverseproxy/reverseproxy.go

@@ -24,7 +24,6 @@ import (
 	"net"
 	"net/http"
 	"regexp"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -328,9 +327,9 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht
 		repl.Set("http.reverse_proxy.upstream.hostport", dialInfo.Address)
 		repl.Set("http.reverse_proxy.upstream.host", dialInfo.Host)
 		repl.Set("http.reverse_proxy.upstream.port", dialInfo.Port)
-		repl.Set("http.reverse_proxy.upstream.requests", strconv.Itoa(upstream.Host.NumRequests()))
-		repl.Set("http.reverse_proxy.upstream.max_requests", strconv.Itoa(upstream.MaxRequests))
-		repl.Set("http.reverse_proxy.upstream.fails", strconv.Itoa(upstream.Host.Fails()))
+		repl.Set("http.reverse_proxy.upstream.requests", upstream.Host.NumRequests())
+		repl.Set("http.reverse_proxy.upstream.max_requests", upstream.MaxRequests)
+		repl.Set("http.reverse_proxy.upstream.fails", upstream.Host.Fails())
 
 		// mutate request headers according to this upstream;
 		// because we're in a retry loop, we have to copy

modules/caddyhttp/rewrite/rewrite.go

@@ -15,8 +15,10 @@
 package rewrite
 
 import (
+	"fmt"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"github.com/caddyserver/caddy/v2"
@@ -208,11 +210,22 @@ func buildQueryString(qs string, repl *caddy.Replacer) string {
 
 		// consume the component and write the result
 		comp := qs[:end]
-		comp, _ = repl.ReplaceFunc(comp, func(name, val string) (string, error) {
+		comp, _ = repl.ReplaceFunc(comp, func(name string, val interface{}) (interface{}, error) {
 			if name == "http.request.uri.query" && wroteVal {
 				return val, nil // already escaped
 			}
-			return url.QueryEscape(val), nil
+			var valStr string
+			switch v := val.(type) {
+			case string:
+				valStr = v
+			case fmt.Stringer:
+				valStr = v.String()
+			case int:
+				valStr = strconv.Itoa(v)
+			default:
+				valStr = fmt.Sprintf("%+v", v)
+			}
+			return url.QueryEscape(valStr), nil
 		})
 		if end < len(qs) {
 			end++ // consume delimiter

modules/caddyhttp/server.go

@@ -21,7 +21,6 @@ import (
 	"net"
 	"net/http"
 	"net/url"
-	"strconv"
 	"strings"
 	"time"
 
@@ -166,9 +165,9 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		defer func() {
 			latency := time.Since(start)
 
-			repl.Set("http.response.status", strconv.Itoa(wrec.Status()))
-			repl.Set("http.response.size", strconv.Itoa(wrec.Size()))
-			repl.Set("http.response.latency", latency.String())
+			repl.Set("http.response.status", wrec.Status())
+			repl.Set("http.response.size", wrec.Size())
+			repl.Set("http.response.latency", latency)
 
 			logger := accLog
 			if s.Logs != nil && s.Logs.LoggerNames != nil {
@@ -360,9 +359,9 @@ func (*HTTPErrorConfig) WithError(r *http.Request, err error) *http.Request {
 
 	// add error values to the replacer
 	repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
-	repl.Set("http.error", err.Error())
+	repl.Set("http.error", err)
 	if handlerErr, ok := err.(HandlerError); ok {
-		repl.Set("http.error.status_code", strconv.Itoa(handlerErr.StatusCode))
+		repl.Set("http.error.status_code", handlerErr.StatusCode)
 		repl.Set("http.error.status_text", http.StatusText(handlerErr.StatusCode))
 		repl.Set("http.error.trace", handlerErr.Trace)
 		repl.Set("http.error.id", handlerErr.ID)

replacer.go

@@ -27,7 +27,7 @@ import (
 // NewReplacer returns a new Replacer.
 func NewReplacer() *Replacer {
 	rep := &Replacer{
-		static: make(map[string]string),
+		static: make(map[string]interface{}),
 	}
 	rep.providers = []ReplacerFunc{
 		globalDefaultReplacements,
@@ -41,7 +41,7 @@ func NewReplacer() *Replacer {
 // use NewReplacer to make one.
 type Replacer struct {
 	providers []ReplacerFunc
-	static    map[string]string
+	static    map[string]interface{}
 }
 
 // Map adds mapFunc to the list of value providers.
@@ -51,19 +51,19 @@ func (r *Replacer) Map(mapFunc ReplacerFunc) {
 }
 
 // Set sets a custom variable to a static value.
-func (r *Replacer) Set(variable, value string) {
+func (r *Replacer) Set(variable string, value interface{}) {
 	r.static[variable] = value
 }
 
 // Get gets a value from the replacer. It returns
 // the value and whether the variable was known.
-func (r *Replacer) Get(variable string) (string, bool) {
+func (r *Replacer) Get(variable string) (interface{}, bool) {
 	for _, mapFunc := range r.providers {
 		if val, ok := mapFunc(variable); ok {
 			return val, true
 		}
 	}
-	return "", false
+	return nil, false
 }
 
 // Delete removes a variable with a static value
@@ -73,9 +73,9 @@ func (r *Replacer) Delete(variable string) {
 }
 
 // fromStatic provides values from r.static.
-func (r *Replacer) fromStatic(key string) (val string, ok bool) {
-	val, ok = r.static[key]
-	return
+func (r *Replacer) fromStatic(key string) (interface{}, bool) {
+	val, ok := r.static[key]
+	return val, ok
 }
 
 // ReplaceOrErr is like ReplaceAll, but any placeholders
@@ -102,10 +102,9 @@ func (r *Replacer) ReplaceAll(input, empty string) string {
 	return out
 }
 
-// ReplaceFunc calls ReplaceAll  efficiently replaces placeholders in input with
-// their values. All placeholders are replaced in the output
-// whether they are recognized or not. Values that are empty
-// string will be substituted with empty.
+// ReplaceFunc is the same as ReplaceAll, but calls f for every
+// replacement to be made, in case f wants to change or inspect
+// the replacement.
 func (r *Replacer) ReplaceFunc(input string, f ReplacementFunc) (string, error) {
 	return r.replace(input, "", true, false, false, f)
 }
@@ -169,9 +168,8 @@ scan:
 				return "", fmt.Errorf("unrecognized placeholder %s%s%s",
 					string(phOpen), key, string(phClose))
 			} else if !treatUnknownAsEmpty {
-				// if treatUnknownAsEmpty is true, we'll
-				// handle an empty val later; so only
-				// continue otherwise
+				// if treatUnknownAsEmpty is true, we'll handle an empty
+				// val later; so only continue otherwise
 				lastWriteCursor = i
 				continue
 			}
@@ -186,9 +184,12 @@ scan:
 			}
 		}
 
+		// convert val to a string as efficiently as possible
+		valStr := toString(val)
+
 		// write the value; if it's empty, either return
 		// an error or write a default value
-		if val == "" {
+		if valStr == "" {
 			if errOnEmpty {
 				return "", fmt.Errorf("evaluated placeholder %s%s%s is empty",
 					string(phOpen), key, string(phClose))
@@ -196,7 +197,7 @@ scan:
 				sb.WriteString(empty)
 			}
 		} else {
-			sb.WriteString(val)
+			sb.WriteString(valStr)
 		}
 
 		// advance cursor to end of placeholder
@@ -210,14 +211,54 @@ scan:
 	return sb.String(), nil
 }
 
+func toString(val interface{}) string {
+	switch v := val.(type) {
+	case nil:
+		return ""
+	case string:
+		return v
+	case fmt.Stringer:
+		return v.String()
+	case byte:
+		return string(v)
+	case []byte:
+		return string(v)
+	case []rune:
+		return string(v)
+	case int:
+		return strconv.Itoa(v)
+	case int32:
+		return strconv.Itoa(int(v))
+	case int64:
+		return strconv.Itoa(int(v))
+	case uint:
+		return strconv.Itoa(int(v))
+	case uint32:
+		return strconv.Itoa(int(v))
+	case uint64:
+		return strconv.Itoa(int(v))
+	case float32:
+		return strconv.FormatFloat(float64(v), 'f', -1, 32)
+	case float64:
+		return strconv.FormatFloat(v, 'f', -1, 64)
+	case bool:
+		if v {
+			return "true"
+		}
+		return "false"
+	default:
+		return fmt.Sprintf("%+v", v)
+	}
+}
+
 // ReplacerFunc is a function that returns a replacement
 // for the given key along with true if the function is able
 // to service that key (even if the value is blank). If the
 // function does not recognize the key, false should be
 // returned.
-type ReplacerFunc func(key string) (val string, ok bool)
+type ReplacerFunc func(key string) (interface{}, bool)
 
-func globalDefaultReplacements(key string) (string, bool) {
+func globalDefaultReplacements(key string) (interface{}, bool) {
 	// check environment variable
 	const envPrefix = "env."
 	if strings.HasPrefix(key, envPrefix) {
@@ -241,7 +282,7 @@ func globalDefaultReplacements(key string) (string, bool) {
 		return strconv.Itoa(nowFunc().Year()), true
 	}
 
-	return "", false
+	return nil, false
 }
 
 // ReplacementFunc is a function that is called when a
@@ -250,7 +291,7 @@ func globalDefaultReplacements(key string) (string, bool) {
 // will be the replacement, and returns the value that
 // will actually be the replacement, or an error. Note
 // that errors are sometimes ignored by replacers.
-type ReplacementFunc func(variable, val string) (string, error)
+type ReplacementFunc func(variable string, val interface{}) (interface{}, error)
 
 // nowFunc is a variable so tests can change it
 // in order to obtain a deterministic time.

replacer_test.go

@@ -173,41 +173,12 @@ func TestReplacer(t *testing.T) {
 	}
 }
 
-func BenchmarkReplacer(b *testing.B) {
-	type testCase struct {
-		name, input, empty string
-	}
-
-	rep := testReplacer()
-
-	for _, bm := range []testCase{
-		{
-			name:  "no placeholder",
-			input: `simple string`,
-		},
-		{
-			name:  "placeholder",
-			input: `{"json": "object"}`,
-		},
-		{
-			name:  "escaped placeholder",
-			input: `\{"json": \{"nested": "{bar}"\}\}`,
-		},
-	} {
-		b.Run(bm.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				rep.ReplaceAll(bm.input, bm.empty)
-			}
-		})
-	}
-}
-
 func TestReplacerSet(t *testing.T) {
 	rep := testReplacer()
 
 	for _, tc := range []struct {
 		variable string
-		value    string
+		value    interface{}
 	}{
 		{
 			variable: "test1",
@@ -217,6 +188,10 @@ func TestReplacerSet(t *testing.T) {
 			variable: "asdf",
 			value:    "123",
 		},
+		{
+			variable: "numbers",
+			value:    123.456,
+		},
 		{
 			variable: "äöü",
 			value:    "öö_äü",
@@ -252,7 +227,7 @@ func TestReplacerSet(t *testing.T) {
 
 	// test if all keys are still there (by length)
 	length := len(rep.static)
-	if len(rep.static) != 7 {
+	if len(rep.static) != 8 {
 		t.Errorf("Expected length '%v' got '%v'", 7, length)
 	}
 }
@@ -261,7 +236,7 @@ func TestReplacerReplaceKnown(t *testing.T) {
 	rep := Replacer{
 		providers: []ReplacerFunc{
 			// split our possible vars to two functions (to test if both functions are called)
-			func(key string) (val string, ok bool) {
+			func(key string) (val interface{}, ok bool) {
 				switch key {
 				case "test1":
 					return "val1", true
@@ -275,7 +250,7 @@ func TestReplacerReplaceKnown(t *testing.T) {
 					return "NOOO", false
 				}
 			},
-			func(key string) (val string, ok bool) {
+			func(key string) (val interface{}, ok bool) {
 				switch key {
 				case "1":
 					return "test-123", true
@@ -331,7 +306,7 @@ func TestReplacerReplaceKnown(t *testing.T) {
 
 func TestReplacerDelete(t *testing.T) {
 	rep := Replacer{
-		static: map[string]string{
+		static: map[string]interface{}{
 			"key1": "val1",
 			"key2": "val2",
 			"key3": "val3",
@@ -366,10 +341,10 @@ func TestReplacerMap(t *testing.T) {
 	rep := testReplacer()
 
 	for i, tc := range []ReplacerFunc{
-		func(key string) (val string, ok bool) {
+		func(key string) (val interface{}, ok bool) {
 			return "", false
 		},
-		func(key string) (val string, ok bool) {
+		func(key string) (val interface{}, ok bool) {
 			return "", false
 		},
 	} {
@@ -434,12 +409,50 @@ func TestReplacerNew(t *testing.T) {
 			}
 		}
 	}
+}
 
+func BenchmarkReplacer(b *testing.B) {
+	type testCase struct {
+		name, input, empty string
+	}
+
+	rep := testReplacer()
+	rep.Set("str", "a string")
+	rep.Set("int", 123.456)
+
+	for _, bm := range []testCase{
+		{
+			name:  "no placeholder",
+			input: `simple string`,
+		},
+		{
+			name:  "string replacement",
+			input: `str={str}`,
+		},
+		{
+			name:  "int replacement",
+			input: `int={int}`,
+		},
+		{
+			name:  "placeholder",
+			input: `{"json": "object"}`,
+		},
+		{
+			name:  "escaped placeholder",
+			input: `\{"json": \{"nested": "{bar}"\}\}`,
+		},
+	} {
+		b.Run(bm.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				rep.ReplaceAll(bm.input, bm.empty)
+			}
+		})
+	}
 }
 
 func testReplacer() Replacer {
 	return Replacer{
 		providers: make([]ReplacerFunc, 0),
-		static:    make(map[string]string),
+		static:    make(map[string]interface{}),
 	}
 }