Merge branch 'master' into transfer-encoding-matchtransfer-encoding-match

1 files changed, 57 insertions, 29 deletions

diff --git a/modules/caddyhttp/fileserver/matcher.go b/modules/caddyhttp/fileserver/matcher.go
index 71de1db29..2bc665d4f 100644
--- a/modules/caddyhttp/fileserver/matcher.go
+++ b/modules/caddyhttp/fileserver/matcher.go
@@ -90,6 +90,7 @@ type MatchFile struct {
 	// How to choose a file in TryFiles. Can be:
 	//
 	// - first_exist
+	// - first_exist_fallback
 	// - smallest_size
 	// - largest_size
 	// - most_recently_modified
@@ -173,7 +174,7 @@ func (m *MatchFile) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 func (MatchFile) CELLibrary(ctx caddy.Context) (cel.Library, error) {
 	requestType := cel.ObjectType("http.Request")
 
-	matcherFactory := func(data ref.Val) (caddyhttp.RequestMatcher, error) {
+	matcherFactory := func(data ref.Val) (caddyhttp.RequestMatcherWithError, error) {
 		values, err := caddyhttp.CELValueToMapStrList(data)
 		if err != nil {
 			return nil, err
@@ -191,7 +192,7 @@ func (MatchFile) CELLibrary(ctx caddy.Context) (cel.Library, error) {
 
 		var try_policy string
 		if len(values["try_policy"]) > 0 {
-			root = values["try_policy"][0]
+			try_policy = values["try_policy"][0]
 		}
 
 		m := MatchFile{
@@ -296,6 +297,7 @@ func (m MatchFile) Validate() error {
 	switch m.TryPolicy {
 	case "",
 		tryPolicyFirstExist,
+		tryPolicyFirstExistFallback,
 		tryPolicyLargestSize,
 		tryPolicySmallestSize,
 		tryPolicyMostRecentlyMod:
@@ -313,12 +315,22 @@ func (m MatchFile) Validate() error {
 //   - http.matchers.file.type: file or directory
 //   - http.matchers.file.remainder: Portion remaining after splitting file path (if configured)
 func (m MatchFile) Match(r *http.Request) bool {
+	match, err := m.selectFile(r)
+	if err != nil {
+		// nolint:staticcheck
+		caddyhttp.SetVar(r.Context(), caddyhttp.MatcherErrorVarKey, err)
+	}
+	return match
+}
+
+// MatchWithError returns true if r matches m.
+func (m MatchFile) MatchWithError(r *http.Request) (bool, error) {
 	return m.selectFile(r)
 }
 
 // selectFile chooses a file according to m.TryPolicy by appending
 // the paths in m.TryFiles to m.Root, with placeholder replacements.
-func (m MatchFile) selectFile(r *http.Request) (matched bool) {
+func (m MatchFile) selectFile(r *http.Request) (bool, error) {
 	repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
 
 	root := filepath.Clean(repl.ReplaceAll(m.Root, "."))
@@ -330,7 +342,7 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 		if c := m.logger.Check(zapcore.ErrorLevel, "use of unregistered filesystem"); c != nil {
 			c.Write(zap.String("fs", fsName))
 		}
-		return false
+		return false, nil
 	}
 	type matchCandidate struct {
 		fullpath, relative, splitRemainder string
@@ -405,13 +417,13 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 	}
 
 	// setPlaceholders creates the placeholders for the matched file
-	setPlaceholders := func(candidate matchCandidate, info fs.FileInfo) {
+	setPlaceholders := func(candidate matchCandidate, isDir bool) {
 		repl.Set("http.matchers.file.relative", filepath.ToSlash(candidate.relative))
 		repl.Set("http.matchers.file.absolute", filepath.ToSlash(candidate.fullpath))
 		repl.Set("http.matchers.file.remainder", filepath.ToSlash(candidate.splitRemainder))
 
 		fileType := "file"
-		if info.IsDir() {
+		if isDir {
 			fileType = "directory"
 		}
 		repl.Set("http.matchers.file.type", fileType)
@@ -419,17 +431,32 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 
 	// match file according to the configured policy
 	switch m.TryPolicy {
-	case "", tryPolicyFirstExist:
-		for _, pattern := range m.TryFiles {
+	case "", tryPolicyFirstExist, tryPolicyFirstExistFallback:
+		maxI := -1
+		if m.TryPolicy == tryPolicyFirstExistFallback {
+			maxI = len(m.TryFiles) - 1
+		}
+
+		for i, pattern := range m.TryFiles {
+			// If the pattern is a status code, emit an error,
+			// which short-circuits the middleware pipeline and
+			// writes an HTTP error response.
 			if err := parseErrorCode(pattern); err != nil {
-				caddyhttp.SetVar(r.Context(), caddyhttp.MatcherErrorVarKey, err)
-				return
+				return false, err
 			}
+
 			candidates := makeCandidates(pattern)
 			for _, c := range candidates {
+				// Skip the IO if using fallback policy and it's the latest item
+				if i == maxI {
+					setPlaceholders(c, false)
+
+					return true, nil
+				}
+
 				if info, exists := m.strictFileExists(fileSystem, c.fullpath); exists {
-					setPlaceholders(c, info)
-					return true
+					setPlaceholders(c, info.IsDir())
+					return true, nil
 				}
 			}
 		}
@@ -450,10 +477,10 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 			}
 		}
 		if largestInfo == nil {
-			return false
+			return false, nil
 		}
-		setPlaceholders(largest, largestInfo)
-		return true
+		setPlaceholders(largest, largestInfo.IsDir())
+		return true, nil
 
 	case tryPolicySmallestSize:
 		var smallestSize int64
@@ -471,10 +498,10 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 			}
 		}
 		if smallestInfo == nil {
-			return false
+			return false, nil
 		}
-		setPlaceholders(smallest, smallestInfo)
-		return true
+		setPlaceholders(smallest, smallestInfo.IsDir())
+		return true, nil
 
 	case tryPolicyMostRecentlyMod:
 		var recent matchCandidate
@@ -491,13 +518,13 @@ func (m MatchFile) selectFile(r *http.Request) (matched bool) {
 			}
 		}
 		if recentInfo == nil {
-			return false
+			return false, nil
 		}
-		setPlaceholders(recent, recentInfo)
-		return true
+		setPlaceholders(recent, recentInfo.IsDir())
+		return true, nil
 	}
 
-	return
+	return false, nil
 }
 
 // parseErrorCode checks if the input is a status
@@ -695,15 +722,16 @@ var globSafeRepl = strings.NewReplacer(
 )
 
 const (
-	tryPolicyFirstExist      = "first_exist"
-	tryPolicyLargestSize     = "largest_size"
-	tryPolicySmallestSize    = "smallest_size"
-	tryPolicyMostRecentlyMod = "most_recently_modified"
+	tryPolicyFirstExist         = "first_exist"
+	tryPolicyFirstExistFallback = "first_exist_fallback"
+	tryPolicyLargestSize        = "largest_size"
+	tryPolicySmallestSize       = "smallest_size"
+	tryPolicyMostRecentlyMod    = "most_recently_modified"
 )
 
 // Interface guards
 var (
-	_ caddy.Validator              = (*MatchFile)(nil)
-	_ caddyhttp.RequestMatcher     = (*MatchFile)(nil)
-	_ caddyhttp.CELLibraryProducer = (*MatchFile)(nil)
+	_ caddy.Validator                   = (*MatchFile)(nil)
+	_ caddyhttp.RequestMatcherWithError = (*MatchFile)(nil)
+	_ caddyhttp.CELLibraryProducer      = (*MatchFile)(nil)
 )