refactor hub dev server

- moved html replacement functionality from vite to go

beszel/internal/hub/hub.go

@@ -112,6 +112,8 @@ func (h *Hub) initialize(e *core.ServeEvent) error {
 	// set URL if BASE_URL env is set
 	if h.appURL != "" {
 		settings.Meta.AppURL = h.appURL
+	} else {
+		h.appURL = settings.Meta.AppURL
 	}
 	if err := e.App.Save(settings); err != nil {
 		return err

beszel/internal/hub/server_development.go

@@ -3,18 +3,74 @@
 package hub
 
 import (
+	"beszel"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"strings"
 
 	"github.com/pocketbase/pocketbase/core"
 )
 
+// Wraps http.RoundTripper to modify dev proxy HTML responses
+type responseModifier struct {
+	transport http.RoundTripper
+	hub       *Hub
+}
+
+func (rm *responseModifier) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := rm.transport.RoundTrip(req)
+	if err != nil {
+		return resp, err
+	}
+	// Only modify HTML responses
+	contentType := resp.Header.Get("Content-Type")
+	if !strings.Contains(contentType, "text/html") {
+		return resp, nil
+	}
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return resp, err
+	}
+	resp.Body.Close()
+	// Create a new response with the modified body
+	modifiedBody := rm.modifyHTML(string(body))
+	resp.Body = io.NopCloser(strings.NewReader(modifiedBody))
+	resp.ContentLength = int64(len(modifiedBody))
+	resp.Header.Set("Content-Length", fmt.Sprintf("%d", len(modifiedBody)))
+
+	return resp, nil
+}
+
+func (rm *responseModifier) modifyHTML(html string) string {
+	parsedURL, err := url.Parse(rm.hub.appURL)
+	if err != nil {
+		return html
+	}
+	// fix base paths in html if using subpath
+	basePath := strings.TrimSuffix(parsedURL.Path, "/") + "/"
+	html = strings.ReplaceAll(html, "./", basePath)
+	html = strings.Replace(html, "{{V}}", beszel.Version, 1)
+	html = strings.Replace(html, "{{HUB_URL}}", rm.hub.appURL, 1)
+	return html
+}
+
 // startServer sets up the development server for Beszel
 func (h *Hub) startServer(se *core.ServeEvent) error {
+	slog.Info("starting server", "appURL", h.appURL)
 	proxy := httputil.NewSingleHostReverseProxy(&url.URL{
 		Scheme: "http",
 		Host:   "localhost:5173",
 	})
+
+	proxy.Transport = &responseModifier{
+		transport: http.DefaultTransport,
+		hub:       h,
+	}
+
 	se.Router.GET("/{path...}", func(e *core.RequestEvent) error {
 		proxy.ServeHTTP(e.Response, e.Request)
 		return nil

beszel/internal/hub/server_production.go

@@ -24,9 +24,9 @@ func (h *Hub) startServer(se *core.ServeEvent) error {
 	// fix base paths in html if using subpath
 	basePath := strings.TrimSuffix(parsedURL.Path, "/") + "/"
 	indexFile, _ := fs.ReadFile(site.DistDirFS, "index.html")
-	indexContent := strings.ReplaceAll(string(indexFile), "./", basePath)
-	indexContent = strings.Replace(indexContent, "{{V}}", beszel.Version, 1)
-	indexContent = strings.Replace(indexContent, "{{HUB_URL}}", h.appURL, 1)
+	html := strings.ReplaceAll(string(indexFile), "./", basePath)
+	html = strings.Replace(html, "{{V}}", beszel.Version, 1)
+	html = strings.Replace(html, "{{HUB_URL}}", h.appURL, 1)
 	// set up static asset serving
 	staticPaths := [2]string{"/static/", "/assets/"}
 	serveStatic := apis.Static(site.DistDirFS, false)
@@ -45,7 +45,7 @@ func (h *Hub) startServer(se *core.ServeEvent) error {
 			e.Response.Header().Del("X-Frame-Options")
 			e.Response.Header().Set("Content-Security-Policy", csp)
 		}
-		return e.HTML(http.StatusOK, indexContent)
+		return e.HTML(http.StatusOK, html)
 	})
 	return nil
 }

beszel/site/vite.config.ts

@@ -3,7 +3,6 @@ import path from "path"
 import tailwindcss from "@tailwindcss/vite"
 import react from "@vitejs/plugin-react-swc"
 import { lingui } from "@lingui/vite-plugin"
-import { version } from "./package.json"
 
 export default defineConfig({
 	base: "./",
@@ -13,13 +12,6 @@ export default defineConfig({
 		}),
 		lingui(),
 		tailwindcss(),
-		{
-			name: "replace version in index.html during dev",
-			apply: "serve",
-			transformIndexHtml(html) {
-				return html.replace("{{V}}", version).replace("{{HUB_URL}}", "")
-			},
-		},
 	],
 	esbuild: {
 		legalComments: "external",