https://github.com/kataras/iris/issues/1562#issuecomment-659845730

_examples/file-server/embedding-gzipped-files-into-app/main.go

@@ -24,7 +24,7 @@ func newApp() *iris.Application {
 		AssetInfo:  GzipAssetInfo,
 		AssetNames: GzipAssetNames,
 		AssetValidator: func(ctx iris.Context, name string) bool {
-			ctx.Header("Vary", "Accept-Encoding")
+			// ctx.Header("Vary", "Accept-Encoding")
 			ctx.Header("Content-Encoding", "gzip")
 			return true
 		},

_examples/file-server/http2push-embedded-gzipped/main.go

@@ -17,10 +17,11 @@ import (
 var opts = iris.DirOptions{
 	IndexName: "/index.html",
 	PushTargets: map[string][]string{
-		"/": {
-			"/public/favicon.ico",
-			"/public/js/main.js",
-			"/public/css/main.css",
+		"/": { // Relative path without route prefix.
+			"favicon.ico",
+			"js/main.js",
+			"css/main.css",
+			// ^ Relative to the index, if need absolute ones start with a slash ('/').
 		},
 	},
 	Compress:   false, // SHOULD be set to false, files already compressed.
@@ -30,7 +31,7 @@ var opts = iris.DirOptions{
 	AssetNames: GzipAssetNames,
 	// Required for pre-compressed files:
 	AssetValidator: func(ctx iris.Context, _ string) bool {
-		ctx.Header("Vary", "Content-Encoding")
+		// ctx.Header("Vary", "Content-Encoding")
 		ctx.Header("Content-Encoding", "gzip")
 		return true
 	},

_examples/file-server/http2push-embedded/main.go

@@ -17,10 +17,11 @@ import (
 var opts = iris.DirOptions{
 	IndexName: "/index.html",
 	PushTargets: map[string][]string{
-		"/": {
-			"/public/favicon.ico",
-			"/public/js/main.js",
-			"/public/css/main.css",
+		"/": { // Relative path without route prefix.
+			"favicon.ico",
+			"js/main.js",
+			"css/main.css",
+			// ^ Relative to the index, if need absolute ones start with a slash ('/').
 		},
 	},
 	Compress:   false,

_examples/file-server/http2push/main.go

@@ -6,18 +6,19 @@ import (
 
 var opts = iris.DirOptions{
 	IndexName: "/index.html",
-	// Optionally register files (map's absolute values) to be served
+	// Optionally register files (map's values) to be served
 	// when a specific path (map's key WITHOUT prefix) is requested
 	// is fired before client asks (HTTP/2 Push).
 	// E.g. "/" (which serves the `IndexName` if not empty).
 	//
 	// Note: Requires running server under TLS,
 	// that's why we use `iris.TLS` below.
 	PushTargets: map[string][]string{
-		"/": {
-			"/public/favicon.ico",
-			"/public/js/main.js",
-			"/public/css/main.css",
+		"/": { // Relative path without route prefix.
+			"favicon.ico",
+			"js/main.js",
+			"css/main.css",
+			// ^ Relative to the index, if need absolute ones start with a slash ('/').
 		},
 	},
 	Compress: true,

context/compress.go

@@ -182,8 +182,8 @@ var _ ResponseWriter = (*CompressResponseWriter)(nil)
 // It returns the best candidate among "gzip", "defate", "br", "snappy" and "s2"
 // based on the request's "Accept-Encoding" header value.
 func AcquireCompressResponseWriter(w ResponseWriter, r *http.Request, level int) (*CompressResponseWriter, error) {
-	acceptEncoding := r.Header.Values(AcceptEncodingHeaderKey)
-
+	// acceptEncoding := r.Header.Values(AcceptEncodingHeaderKey)
+	acceptEncoding := r.Header[AcceptEncodingHeaderKey]
 	if len(acceptEncoding) == 0 {
 		return nil, ErrResponseNotCompressed
 	}

core/router/fs.go

@@ -44,10 +44,10 @@ type DirOptions struct {
 	// that another handler, called index handler, is auto-registered by the framework
 	// if end developer does not managed to handle it by hand.
 	IndexName string
-	// PushTargets optionally absolute filenames (map's value) to be served without any
-	// additional client's requests (HTTP/2 Push)
-	// when a specific path (map's key) is requested and
-	// it's not a directory (it's an `IndexFile`).
+	// PushTargets filenames (map's value) to
+	// be served without additional client's requests (HTTP/2 Push)
+	// when a specific request path (map's key WITHOUT prefix)
+	// is requested and it's not a directory (it's an `IndexFile`).
 	PushTargets map[string][]string
 	// When files should served under compression.
 	Compress bool
@@ -88,6 +88,14 @@ func getDirOptions(opts ...DirOptions) (options DirOptions) {
 		options.Attachments.Burst = 0
 	}
 
+	// Make sure PushTarget's paths are in the proper form.
+	for path, filenames := range options.PushTargets {
+		for idx, filename := range filenames {
+			filenames[idx] = filepath.ToSlash(filename)
+		}
+		options.PushTargets[path] = filenames
+	}
+
 	return
 }
 
@@ -382,8 +390,9 @@ func FileServer(directory string, opts ...DirOptions) context.Handler {
 	}
 
 	h := func(ctx *context.Context) {
-		name := prefix(ctx.Request().URL.Path, "/")
-		ctx.Request().URL.Path = name
+		r := ctx.Request()
+		name := prefix(r.URL.Path, "/")
+		r.URL.Path = name
 
 		f, err := fs.Open(name)
 		if err != nil {
@@ -423,6 +432,30 @@ func FileServer(directory string, opts ...DirOptions) context.Handler {
 			}
 		}
 
+		if indexFound && !options.Attachments.Enable {
+			if indexAssets, ok := options.PushTargets[name]; ok {
+				if pusher, ok := ctx.ResponseWriter().(http.Pusher); ok {
+					for _, indexAsset := range indexAssets {
+						// pushOpts := &http.PushOptions{
+						// 	Method: "GET",
+						// 	Header: http.Header{
+						// 		"Vary":             []string{"Accept-Encoding"},
+						// 		"Content-Encoding": []string{"gzip"},
+						// 	},
+						// }
+						if indexAsset[0] != '/' {
+							// it's relative path.
+							indexAsset = path.Join(r.RequestURI, indexAsset)
+						}
+
+						if err = pusher.Push(indexAsset, nil); err != nil {
+							break
+						}
+					}
+				}
+			}
+		}
+
 		// Still a directory? (we didn't find an index.html file)
 		if info.IsDir() {
 			if !options.ShowList {
@@ -486,16 +519,6 @@ func FileServer(directory string, opts ...DirOptions) context.Handler {
 
 		ctx.Compress(options.Compress)
 
-		if indexFound && len(options.PushTargets) > 0 && !options.Attachments.Enable {
-			if indexAssets, ok := options.PushTargets[name]; ok {
-				if pusher, ok := ctx.ResponseWriter().(http.Pusher); ok {
-					for _, indexAsset := range indexAssets {
-						pusher.Push(indexAsset, nil)
-					}
-				}
-			}
-		}
-
 		// If limit is 0 then same as ServeContent.
 		ctx.ServeContentWithRate(f, info.Name(), info.ModTime(), options.Attachments.Limit, options.Attachments.Burst)
 		if serveCode := ctx.GetStatusCode(); context.StatusCodeNotSuccessful(serveCode) {