perf: use zap's Check() to prevent useless allocs (#6560)

* perf: use zap's Check() to prevent useless allocs

* fix

* fix

* fix

* fix

* restore previous replacer behavior

* fix linter

modules/caddyhttp/caddyauth/caddyauth.go

@@ -19,6 +19,7 @@ import (
 	"net/http"
 
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
@@ -76,9 +77,9 @@ func (a Authentication) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 	for provName, prov := range a.Providers {
 		user, authed, err = prov.Authenticate(w, r)
 		if err != nil {
-			a.logger.Error("auth provider returned error",
-				zap.String("provider", provName),
-				zap.Error(err))
+			if c := a.logger.Check(zapcore.ErrorLevel, "auth provider returned error"); c != nil {
+				c.Write(zap.String("provider", provName), zap.Error(err))
+			}
 			continue
 		}
 		if authed {

modules/caddyhttp/fileserver/browse.go

@@ -33,6 +33,7 @@ import (
 	"time"
 
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
@@ -68,9 +69,9 @@ type Browse struct {
 }
 
 func (fsrv *FileServer) serveBrowse(fileSystem fs.FS, root, dirPath string, w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
-	fsrv.logger.Debug("browse enabled; listing directory contents",
-		zap.String("path", dirPath),
-		zap.String("root", root))
+	if c := fsrv.logger.Check(zapcore.DebugLevel, "browse enabled; listing directory contents"); c != nil {
+		c.Write(zap.String("path", dirPath), zap.String("root", root))
+	}
 
 	// Navigation on the client-side gets messed up if the
 	// URL doesn't end in a trailing slash because hrefs to
@@ -92,7 +93,9 @@ func (fsrv *FileServer) serveBrowse(fileSystem fs.FS, root, dirPath string, w ht
 	origReq := r.Context().Value(caddyhttp.OriginalRequestCtxKey).(http.Request)
 	if r.URL.Path == "" || path.Base(origReq.URL.Path) == path.Base(r.URL.Path) {
 		if !strings.HasSuffix(origReq.URL.Path, "/") {
-			fsrv.logger.Debug("redirecting to trailing slash to preserve hrefs", zap.String("request_path", r.URL.Path))
+			if c := fsrv.logger.Check(zapcore.DebugLevel, "redirecting to trailing slash to preserve hrefs"); c != nil {
+				c.Write(zap.String("request_path", r.URL.Path))
+			}
 			return redirect(w, r, origReq.URL.Path+"/")
 		}
 	}

modules/caddyhttp/fileserver/browsetplcontext.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/dustin/go-humanize"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
@@ -57,9 +58,9 @@ func (fsrv *FileServer) directoryListing(ctx context.Context, fileSystem fs.FS,
 
 		info, err := entry.Info()
 		if err != nil {
-			fsrv.logger.Error("could not get info about directory entry",
-				zap.String("name", entry.Name()),
-				zap.String("root", root))
+			if c := fsrv.logger.Check(zapcore.ErrorLevel, "could not get info about directory entry"); c != nil {
+				c.Write(zap.String("name", entry.Name()), zap.String("root", root))
+			}
 			continue
 		}
 

modules/caddyhttp/fileserver/matcher.go

@@ -33,6 +33,7 @@ import (
 	"github.com/google/cel-go/common/types/ref"
 	"github.com/google/cel-go/parser"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
@@ -326,7 +327,9 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 
 	fileSystem, ok := m.fsmap.Get(fsName)
 	if !ok {
-		m.logger.Error("use of unregistered filesystem", zap.String("fs", fsName))
+		if c := m.logger.Check(zapcore.ErrorLevel, "use of unregistered filesystem"); c != nil {
+			c.Write(zap.String("fs", fsName))
+		}
 		return false
 	}
 	type matchCandidate struct {
@@ -356,7 +359,10 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 			return val, nil
 		})
 		if err != nil {
-			m.logger.Error("evaluating placeholders", zap.Error(err))
+			if c := m.logger.Check(zapcore.ErrorLevel, "evaluating placeholders"); c != nil {
+				c.Write(zap.Error(err))
+			}
+
 			expandedFile = file // "oh well," I guess?
 		}
 
@@ -379,7 +385,9 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 		} else {
 			globResults, err = fs.Glob(fileSystem, fullPattern)
 			if err != nil {
-				m.logger.Error("expanding glob", zap.Error(err))
+				if c := m.logger.Check(zapcore.ErrorLevel, "expanding glob"); c != nil {
+					c.Write(zap.Error(err))
+				}
 			}
 		}
 

modules/caddyhttp/fileserver/staticfiles.go

@@ -31,6 +31,7 @@ import (
 	"strings"
 
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
@@ -286,11 +287,14 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 	// remove any trailing `/` as it breaks fs.ValidPath() in the stdlib
 	filename := strings.TrimSuffix(caddyhttp.SanitizedPathJoin(root, r.URL.Path), "/")
 
-	fsrv.logger.Debug("sanitized path join",
-		zap.String("site_root", root),
-		zap.String("fs", fsName),
-		zap.String("request_path", r.URL.Path),
-		zap.String("result", filename))
+	if c := fsrv.logger.Check(zapcore.DebugLevel, "sanitized path join"); c != nil {
+		c.Write(
+			zap.String("site_root", root),
+			zap.String("fs", fsName),
+			zap.String("request_path", r.URL.Path),
+			zap.String("result", filename),
+		)
+	}
 
 	// get information about the file
 	info, err := fs.Stat(fileSystem, filename)
@@ -313,9 +317,12 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 			indexPath := caddyhttp.SanitizedPathJoin(filename, indexPage)
 			if fileHidden(indexPath, filesToHide) {
 				// pretend this file doesn't exist
-				fsrv.logger.Debug("hiding index file",
-					zap.String("filename", indexPath),
-					zap.Strings("files_to_hide", filesToHide))
+				if c := fsrv.logger.Check(zapcore.DebugLevel, "hiding index file"); c != nil {
+					c.Write(
+						zap.String("filename", indexPath),
+						zap.Strings("files_to_hide", filesToHide),
+					)
+				}
 				continue
 			}
 
@@ -335,17 +342,22 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 			info = indexInfo
 			filename = indexPath
 			implicitIndexFile = true
-			fsrv.logger.Debug("located index file", zap.String("filename", filename))
+			if c := fsrv.logger.Check(zapcore.DebugLevel, "located index file"); c != nil {
+				c.Write(zap.String("filename", filename))
+			}
 			break
 		}
 	}
 
 	// if still referencing a directory, delegate
 	// to browse or return an error
 	if info.IsDir() {
-		fsrv.logger.Debug("no index file in directory",
-			zap.String("path", filename),
-			zap.Strings("index_filenames", fsrv.IndexNames))
+		if c := fsrv.logger.Check(zapcore.DebugLevel, "no index file in directory"); c != nil {
+			c.Write(
+				zap.String("path", filename),
+				zap.Strings("index_filenames", fsrv.IndexNames),
+			)
+		}
 		if fsrv.Browse != nil && !fileHidden(filename, filesToHide) {
 			return fsrv.serveBrowse(fileSystem, root, filename, w, r, next)
 		}
@@ -355,9 +367,12 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 	// one last check to ensure the file isn't hidden (we might
 	// have changed the filename from when we last checked)
 	if fileHidden(filename, filesToHide) {
-		fsrv.logger.Debug("hiding file",
-			zap.String("filename", filename),
-			zap.Strings("files_to_hide", filesToHide))
+		if c := fsrv.logger.Check(zapcore.DebugLevel, "hiding file"); c != nil {
+			c.Write(
+				zap.String("filename", filename),
+				zap.Strings("files_to_hide", filesToHide),
+			)
+		}
 		return fsrv.notFound(w, r, next)
 	}
 
@@ -375,15 +390,21 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 		if path.Base(origReq.URL.Path) == path.Base(r.URL.Path) {
 			if implicitIndexFile && !strings.HasSuffix(origReq.URL.Path, "/") {
 				to := origReq.URL.Path + "/"
-				fsrv.logger.Debug("redirecting to canonical URI (adding trailing slash for directory)",
-					zap.String("from_path", origReq.URL.Path),
-					zap.String("to_path", to))
+				if c := fsrv.logger.Check(zapcore.DebugLevel, "redirecting to canonical URI (adding trailing slash for directory"); c != nil {
+					c.Write(
+						zap.String("from_path", origReq.URL.Path),
+						zap.String("to_path", to),
+					)
+				}
 				return redirect(w, r, to)
 			} else if !implicitIndexFile && strings.HasSuffix(origReq.URL.Path, "/") {
 				to := origReq.URL.Path[:len(origReq.URL.Path)-1]
-				fsrv.logger.Debug("redirecting to canonical URI (removing trailing slash for file)",
-					zap.String("from_path", origReq.URL.Path),
-					zap.String("to_path", to))
+				if c := fsrv.logger.Check(zapcore.DebugLevel, "redirecting to canonical URI (removing trailing slash for file"); c != nil {
+					c.Write(
+						zap.String("from_path", origReq.URL.Path),
+						zap.String("to_path", to),
+					)
+				}
 				return redirect(w, r, to)
 			}
 		}
@@ -411,13 +432,19 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 		compressedFilename := filename + precompress.Suffix()
 		compressedInfo, err := fs.Stat(fileSystem, compressedFilename)
 		if err != nil || compressedInfo.IsDir() {
-			fsrv.logger.Debug("precompressed file not accessible", zap.String("filename", compressedFilename), zap.Error(err))
+			if c := fsrv.logger.Check(zapcore.DebugLevel, "precompressed file not accessible"); c != nil {
+				c.Write(zap.String("filename", compressedFilename), zap.Error(err))
+			}
 			continue
 		}
-		fsrv.logger.Debug("opening compressed sidecar file", zap.String("filename", compressedFilename), zap.Error(err))
+		if c := fsrv.logger.Check(zapcore.DebugLevel, "opening compressed sidecar file"); c != nil {
+			c.Write(zap.String("filename", compressedFilename), zap.Error(err))
+		}
 		file, err = fsrv.openFile(fileSystem, compressedFilename, w)
 		if err != nil {
-			fsrv.logger.Warn("opening precompressed file failed", zap.String("filename", compressedFilename), zap.Error(err))
+			if c := fsrv.logger.Check(zapcore.WarnLevel, "opening precompressed file failed"); c != nil {
+				c.Write(zap.String("filename", compressedFilename), zap.Error(err))
+			}
 			if caddyErr, ok := err.(caddyhttp.HandlerError); ok && caddyErr.StatusCode == http.StatusServiceUnavailable {
 				return err
 			}
@@ -448,7 +475,9 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
 
 	// no precompressed file found, use the actual file
 	if file == nil {
-		fsrv.logger.Debug("opening file", zap.String("filename", filename))
+		if c := fsrv.logger.Check(zapcore.DebugLevel, "opening file"); c != nil {
+			c.Write(zap.String("filename", filename))
+		}
 
 		// open the file
 		file, err = fsrv.openFile(fileSystem, filename, w)
@@ -548,18 +577,24 @@ func (fsrv *FileServer) openFile(fileSystem fs.FS, filename string, w http.Respo
 	if err != nil {
 		err = fsrv.mapDirOpenError(fileSystem, err, filename)
 		if errors.Is(err, fs.ErrNotExist) {
-			fsrv.logger.Debug("file not found", zap.String("filename", filename), zap.Error(err))
+			if c := fsrv.logger.Check(zapcore.DebugLevel, "file not found"); c != nil {
+				c.Write(zap.String("filename", filename), zap.Error(err))
+			}
 			return nil, caddyhttp.Error(http.StatusNotFound, err)
 		} else if errors.Is(err, fs.ErrPermission) {
-			fsrv.logger.Debug("permission denied", zap.String("filename", filename), zap.Error(err))
+			if c := fsrv.logger.Check(zapcore.DebugLevel, "permission denied"); c != nil {
+				c.Write(zap.String("filename", filename), zap.Error(err))
+			}
 			return nil, caddyhttp.Error(http.StatusForbidden, err)
 		}
 		// maybe the server is under load and ran out of file descriptors?
 		// have client wait arbitrary seconds to help prevent a stampede
 		//nolint:gosec
 		backoff := weakrand.Intn(maxBackoff-minBackoff) + minBackoff
 		w.Header().Set("Retry-After", strconv.Itoa(backoff))
-		fsrv.logger.Debug("retry after backoff", zap.String("filename", filename), zap.Int("backoff", backoff), zap.Error(err))
+		if c := fsrv.logger.Check(zapcore.DebugLevel, "retry after backoff"); c != nil {
+			c.Write(zap.String("filename", filename), zap.Int("backoff", backoff), zap.Error(err))
+		}
 		return nil, caddyhttp.Error(http.StatusServiceUnavailable, err)
 	}
 	return file, nil

modules/caddyhttp/intercept/intercept.go

@@ -23,6 +23,7 @@ import (
 	"sync"
 
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
@@ -165,7 +166,9 @@ func (ir Intercept) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddy
 	}
 	repl.Set("http.intercept.status_code", rec.Status())
 
-	ir.logger.Debug("handling response", zap.Int("handler", rec.handlerIndex))
+	if c := ir.logger.Check(zapcore.DebugLevel, "handling response"); c != nil {
+		c.Write(zap.Int("handler", rec.handlerIndex))
+	}
 
 	// pass the request through the response handler routes
 	return rec.handler.Routes.Compile(next).ServeHTTP(w, r)

modules/caddyhttp/ip_matchers.go

@@ -26,6 +26,7 @@ import (
 	"github.com/google/cel-go/cel"
 	"github.com/google/cel-go/common/types/ref"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
@@ -150,12 +151,17 @@ func (m MatchRemoteIP) Match(r *http.Request) bool {
 	address := r.RemoteAddr
 	clientIP, zoneID, err := parseIPZoneFromString(address)
 	if err != nil {
-		m.logger.Error("getting remote IP", zap.Error(err))
+		if c := m.logger.Check(zapcore.ErrorLevel, "getting remote "); c != nil {
+			c.Write(zap.Error(err))
+		}
+
 		return false
 	}
 	matches, zoneFilter := matchIPByCidrZones(clientIP, zoneID, m.cidrs, m.zones)
 	if !matches && !zoneFilter {
-		m.logger.Debug("zone ID from remote IP did not match", zap.String("zone", zoneID))
+		if c := m.logger.Check(zapcore.DebugLevel, "zone ID from remote IP did not match"); c != nil {
+			c.Write(zap.String("zone", zoneID))
+		}
 	}
 	return matches
 }

modules/caddyhttp/logging.go

@@ -193,7 +193,7 @@ func (sa *StringArray) UnmarshalJSON(b []byte) error {
 // to use, the error log message, and any extra fields.
 // If err is a HandlerError, the returned values will
 // have richer information.
-func errLogValues(err error) (status int, msg string, fields []zapcore.Field) {
+func errLogValues(err error) (status int, msg string, fields func() []zapcore.Field) {
 	var handlerErr HandlerError
 	if errors.As(err, &handlerErr) {
 		status = handlerErr.StatusCode
@@ -202,10 +202,12 @@ func errLogValues(err error) (status int, msg string, fields []zapcore.Field) {
 		} else {
 			msg = handlerErr.Err.Error()
 		}
-		fields = []zapcore.Field{
-			zap.Int("status", handlerErr.StatusCode),
-			zap.String("err_id", handlerErr.ID),
-			zap.String("err_trace", handlerErr.Trace),
+		fields = func() []zapcore.Field {
+			return []zapcore.Field{
+				zap.Int("status", handlerErr.StatusCode),
+				zap.String("err_id", handlerErr.ID),
+				zap.String("err_trace", handlerErr.Trace),
+			}
 		}
 		return
 	}