feat: add embedded-fs support

moonshot.go

@@ -3,6 +3,7 @@ package moonshot
 import (
 	"context"
 	"fmt"
+	"io/fs"
 
 	"github.com/go-chi/chi"
 	"github.com/spf13/cobra"
@@ -12,11 +13,12 @@ import (
 // App represents an instance of app command. Invoke App.Launch()
 // in `main()`.
 type App struct {
-	Name   string
-	Short  string
-	Long   string
-	CfgPtr interface{}
-	Routes func(r *chi.Mux)
+	Name     string
+	Short    string
+	Long     string
+	CfgPtr   interface{}
+	Routes   func(r *chi.Mux)
+	StaticFS fs.FS
 }
 
 func (app *App) Launch(ctx context.Context, cmds ...*cobra.Command) int {

moonshot_server.go

@@ -2,7 +2,14 @@ package moonshot
 
 import (
 	"context"
+	"fmt"
+	"io"
+	"io/fs"
+	"mime"
 	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/go-chi/chi"
@@ -31,12 +38,14 @@ func (cli *App) cmdServe(ctx context.Context) *cobra.Command {
 			router.Get("/health", pingHandler(map[string]interface{}{
 				"status": "ok",
 			}))
-			if staticRoute != "" {
+			cli.Routes(router)
+
+			if cli.StaticFS != nil {
+				router.Mount(staticRoute, staticHandler(cli.StaticFS))
+			} else if staticDir != "" {
 				router.Mount(staticRoute, http.StripPrefix(staticRoute, http.FileServer(http.Dir(staticDir))))
 			}
 
-			cli.Routes(router)
-
 			log.Infof(ctx, "starting server at '%s'...", addr)
 			if err := httputils.GracefulServe(ctx, graceDur, addr, router); err != nil {
 				log.Fatalf(ctx, "server exited with error: %v", err)
@@ -45,7 +54,7 @@ func (cli *App) cmdServe(ctx context.Context) *cobra.Command {
 	}
 
 	cmd.Flags().StringVarP(&addr, "addr", "a", ":8080", "Bind address for HTTP server")
-	cmd.Flags().StringVarP(&staticDir, "static-dir", "D", "./app", "Directory to serve static files from")
+	cmd.Flags().StringVarP(&staticDir, "static-dir", "D", "", "Directory to serve static files from")
 	cmd.Flags().StringVarP(&staticRoute, "static-route", "R", "/", "Route to serve static files under")
 	cmd.Flags().DurationVarP(&graceDur, "grace-period", "G", 5*time.Second, "Grace period for shutdown")
 	return cmd
@@ -70,3 +79,44 @@ func pingHandler(info map[string]interface{}) http.HandlerFunc {
 		httputils.Respond(wr, req, http.StatusOK, info)
 	}
 }
+
+func staticHandler(staticFS fs.FS) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
+			return
+		}
+
+		path := filepath.Clean(r.URL.Path)
+		if path == "/" { // Add other paths that you route on the UI side here
+			path = "index.html"
+		}
+		path = strings.TrimPrefix(path, "/")
+
+		file, err := staticFS.Open(path)
+		if err != nil {
+			if os.IsNotExist(err) {
+				log.Warnf(r.Context(), "file '%s' not found: %v", path, err)
+				http.NotFound(w, r)
+				return
+			}
+			log.Warnf(r.Context(), "failed to open '%s': %v", path, err)
+			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			return
+		}
+
+		contentType := mime.TypeByExtension(filepath.Ext(path))
+		w.Header().Set("Content-Type", contentType)
+		if strings.HasPrefix(path, "static/") {
+			w.Header().Set("Cache-Control", "public, max-age=31536000")
+		}
+
+		stat, err := file.Stat()
+		if err == nil && stat.Size() > 0 {
+			w.Header().Set("Content-Length", fmt.Sprintf("%d", stat.Size()))
+		}
+
+		n, _ := io.Copy(w, file)
+		log.Debugf(r.Context(), "%d bytes copied to client from file '%s'", n, path)
+	}
+}