refac: rethought the complete workflow and deployement flow ; docs etc.

api/handlers/frontend/frontHandler.go

@@ -5,13 +5,23 @@ import (
 	"io"
 	"io/fs"
 	"net/http"
-	"path/filepath"
+	"path"
 	"strings"
 	"time"
 
 	"github.com/go-chi/chi/v5"
 )
 
+const hashedAssetsPrefix = "assets/"
+
+const (
+	hashedAssetCacheControl = "public, max-age=31536000, immutable"
+	staticFileCacheControl  = "public, max-age=3600"
+	indexCacheControl       = "no-store, no-cache, must-revalidate"
+)
+
+const devNotice = "RenewCMS was built with -tags nofrontend: the SPA is served by the Vite dev server (http://localhost:5173)."
+
 type spaHandler struct {
 	staticFS fs.FS
 	modTime  time.Time
@@ -20,9 +30,13 @@ type spaHandler struct {
 func NewFrontendRouter() http.Handler {
 	r := chi.NewRouter()
 
-	distFS, _ := fs.Sub(assets.DistEmbed, "dist")
+	if assets.Dist == nil {
+		r.Get("/*", serveDevNotice)
+		return r
+	}
+
 	handler := &spaHandler{
-		staticFS: distFS,
+		staticFS: assets.Dist,
 		modTime:  time.Now(),
 	}
 
@@ -30,6 +44,12 @@ func NewFrontendRouter() http.Handler {
 	return r
 }
 
+func serveDevNotice(w http.ResponseWriter, _ *http.Request) {
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.WriteHeader(http.StatusNotFound)
+	_, _ = io.WriteString(w, devNotice)
+}
+
 func (h *spaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	path := h.cleanPath(r.URL.Path)
 	if h.fileExists(path) {
@@ -39,8 +59,8 @@ func (h *spaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	h.serveIndex(w, r)
 }
 
-func (h *spaHandler) cleanPath(path string) string {
-	return strings.TrimPrefix(filepath.Clean(path), "/")
+func (h *spaHandler) cleanPath(p string) string {
+	return strings.TrimPrefix(path.Clean("/"+p), "/")
 }
 
 func (h *spaHandler) fileExists(path string) bool {
@@ -52,11 +72,16 @@ func (h *spaHandler) fileExists(path string) bool {
 		return false
 	}
 	defer f.Close()
-	return true
+	stat, err := f.Stat()
+	return err == nil && !stat.IsDir()
 }
 
 func (h *spaHandler) serveAsset(w http.ResponseWriter, r *http.Request, path string) {
-	w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+	if strings.HasPrefix(path, hashedAssetsPrefix) {
+		w.Header().Set("Cache-Control", hashedAssetCacheControl)
+	} else {
+		w.Header().Set("Cache-Control", staticFileCacheControl)
+	}
 	http.FileServer(http.FS(h.staticFS)).ServeHTTP(w, r)
 }
 
@@ -74,6 +99,6 @@ func (h *spaHandler) serveIndex(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate")
+	w.Header().Set("Cache-Control", indexCacheControl)
 	http.ServeContent(w, r, "index.html", h.modTime, content)
 }