diff --git a/internal/server/server.go b/internal/server/server.go
index d40d981..b59592d 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -55,10 +55,11 @@ type Server struct {
tunnelMu sync.Mutex // serializes port changes
tunnelPort atomic.Int64
- stats statCache // last load sample per agent, for the status page
- relays speedRelays // speed tests that run through the browser
- meters speedMeters // byte counts of the speed tests under way
- xfers xfers // files on their way between a browser and an agent
+ stats statCache // last load sample per agent, for the status page
+ relays speedRelays // speed tests that run through the browser
+ meters speedMeters // byte counts of the speed tests under way
+ xfers xfers // files on their way between a browser and an agent
+ assets map[string]string // static file -> hash of its content
}
// New builds the server, parsing embedded templates.
@@ -66,7 +67,14 @@ func New(opts Options) (*Server, error) {
if err := opts.DB.ensureDefaults(); err != nil {
return nil, err
}
- tmpl, err := template.ParseFS(webFS, "web/templates/*.html")
+ staticFS, _ := fs.Sub(webFS, "web/static")
+ assets := assetHashes(staticFS)
+ funcs := template.FuncMap{
+ // asset is a static file's URL with its content hash, so a new
+ // release is a new URL that no browser or proxy has cached.
+ "asset": func(name string) string { return "/static/" + name + "?v=" + assets[name] },
+ }
+ tmpl, err := template.New("").Funcs(funcs).ParseFS(webFS, "web/templates/*.html")
if err != nil {
return nil, err
}
@@ -92,6 +100,7 @@ func New(opts Options) (*Server, error) {
distDir: opts.DistDir,
secureCookies: opts.SecureCookies,
installTmpl: installTmpl,
+ assets: assets,
}
s.ufw = newUfwManager(opts.DB, s.TunnelPort)
// Start the direct forward tunnel (TCP mux + UDP), on the port from the
@@ -186,7 +195,7 @@ func (s *Server) Handler() http.Handler {
// Static assets (xterm.js etc.) from the embedded FS.
staticFS, _ := fs.Sub(webFS, "web/static")
- mux.Handle("GET /static/", http.StripPrefix("/static/", staticHandler(staticFS)))
+ mux.Handle("GET /static/", http.StripPrefix("/static/", staticHandler(staticFS, s.assets)))
// Public: install script + agent binary downloads.
mux.HandleFunc("GET /install.sh", s.handleInstallScript)
@@ -336,32 +345,38 @@ func clientIP(r *http.Request) string {
return host
}
-// staticHandler serves the embedded assets with a content hash as ETag. The
-// browser asks each time whether a file changed (no-cache) and gets a 304
-// when it did not, so a new release reaches it at once without reloading
-// what stayed the same.
-func staticHandler(fsys fs.FS) http.Handler {
+// assetHashes hashes every static file, for asset URLs and ETags.
+func assetHashes(fsys fs.FS) map[string]string {
+ out := map[string]string{}
+ _ = fs.WalkDir(fsys, ".", func(p string, d fs.DirEntry, err error) error {
+ if err != nil || d.IsDir() {
+ return nil
+ }
+ if data, err := fs.ReadFile(fsys, p); err == nil {
+ sum := sha256.Sum256(data)
+ out[p] = hex.EncodeToString(sum[:8])
+ }
+ return nil
+ })
+ return out
+}
+
+// staticHandler serves the embedded assets. Pages ask for them by URLs that
+// carry the content hash (?v=): such a file never changes and is kept for a
+// year, by the browser and by a proxy in front such as Cloudflare. Asked for
+// without it, a file is checked every time against its ETag.
+func staticHandler(fsys fs.FS, hashes map[string]string) http.Handler {
files := http.FileServer(http.FS(fsys))
- var mu sync.Mutex
- etags := map[string]string{}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
- name := strings.TrimPrefix(r.URL.Path, "/")
- mu.Lock()
- tag, ok := etags[name]
- mu.Unlock()
- if !ok {
- if data, err := fs.ReadFile(fsys, name); err == nil {
- sum := sha256.Sum256(data)
- tag = `"` + hex.EncodeToString(sum[:8]) + `"`
- }
- mu.Lock()
- etags[name] = tag
- mu.Unlock()
+ h := hashes[strings.TrimPrefix(r.URL.Path, "/")]
+ if h != "" {
+ w.Header().Set("ETag", `"`+h+`"`)
}
- if tag != "" {
- w.Header().Set("ETag", tag)
+ if v := r.URL.Query().Get("v"); h != "" && v == h {
+ w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+ } else {
+ w.Header().Set("Cache-Control", "no-cache")
}
- w.Header().Set("Cache-Control", "no-cache")
files.ServeHTTP(w, r)
})
}
diff --git a/internal/server/web/templates/dashboard.html b/internal/server/web/templates/dashboard.html
index 3bd9b9c..fa496ef 100644
--- a/internal/server/web/templates/dashboard.html
+++ b/internal/server/web/templates/dashboard.html
@@ -4,7 +4,7 @@
Машины - LPRA
-
+
diff --git a/internal/server/web/templates/edit.html b/internal/server/web/templates/edit.html
index 4160acb..b4ac97b 100644
--- a/internal/server/web/templates/edit.html
+++ b/internal/server/web/templates/edit.html
@@ -4,7 +4,7 @@
Изменить машину - LPRA
-
+
diff --git a/internal/server/web/templates/files.html b/internal/server/web/templates/files.html
index cdc4a36..578efd3 100644
--- a/internal/server/web/templates/files.html
+++ b/internal/server/web/templates/files.html
@@ -4,8 +4,8 @@
Файлы · {{.Agent.Name}} - LPRA
-
-
+
+