Add upload progress bar with SSE extraction status

ISO uploads now show a progress bar during file transfer (via XHR
upload.onprogress) and real-time extraction status (via SSE events
through the existing Hub). Falls back to plain form POST if JS is
disabled.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/api/render.go

@@ -160,7 +160,8 @@ func imageUploadForm(errMsg string) string {
 	return layout("Upload Image", fmt.Sprintf(`
 		<h2>Upload Boot Image</h2>
 		%s
-		<form method="POST" action="/images/upload" enctype="multipart/form-data" class="form">
+		<form id="upload-form" method="POST" action="/images/upload" enctype="multipart/form-data" class="form">
+			<input type="hidden" name="upload_id" id="upload-id" value="">
 			<label>Name<input type="text" name="name" placeholder="proxmox-8.2" required pattern="[a-z0-9][a-z0-9.\-]*"></label>
 			<label>Version<input type="text" name="version" placeholder="8.2-1" required></label>
 			<label>Kind
@@ -169,9 +170,16 @@ func imageUploadForm(errMsg string) string {
 				</select>
 			</label>
 			<label>ISO File<input type="file" name="iso" accept=".iso" required></label>
-			<p style="font-size:0.8rem;color:var(--text-muted);margin-bottom:0.5rem">Upload may take several minutes for large ISOs. The kernel and initrd will be extracted automatically.</p>
 			<button type="submit" class="btn">Upload &amp; Extract</button>
 		</form>
+		<div id="upload-progress" style="display:none" class="upload-progress">
+			<h3 id="progress-title">Uploading ISO...</h3>
+			<div class="progress-bar-track">
+				<div class="progress-bar-fill" id="progress-fill"></div>
+			</div>
+			<div class="progress-text" id="progress-text">Preparing upload...</div>
+			<div class="progress-detail" id="progress-detail"></div>
+		</div>
 	`, errHTML))
 }
 

internal/api/ui.go

@@ -167,35 +167,65 @@ func (u *UI) NewImageForm(w http.ResponseWriter, r *http.Request) {
 }
 
 func (u *UI) UploadImage(w http.ResponseWriter, r *http.Request) {
+	isXHR := r.Header.Get("X-Requested-With") == "XMLHttpRequest"
+
 	if err := r.ParseMultipartForm(0); err != nil {
+		if isXHR {
+			writeJSON(w, http.StatusBadRequest, map[string]any{"ok": false, "error": "Invalid form submission"})
+		} else {
 			renderHTML(w, imageUploadForm("Invalid form submission"))
+		}
 		return
 	}
 
 	name := strings.TrimSpace(r.FormValue("name"))
 	version := strings.TrimSpace(r.FormValue("version"))
 	kind := strings.TrimSpace(r.FormValue("kind"))
+	uploadID := strings.TrimSpace(r.FormValue("upload_id"))
 
 	file, _, err := r.FormFile("iso")
 	if err != nil {
+		if isXHR {
+			writeJSON(w, http.StatusBadRequest, map[string]any{"ok": false, "error": "ISO file is required"})
+		} else {
 			renderHTML(w, imageUploadForm("ISO file is required"))
+		}
 		return
 	}
 	defer file.Close()
 
+	var progressFn image.ProgressFunc
+	if uploadID != "" {
+		progressFn = func(stage, detail string) {
+			u.Hub.Publish(events.Event{
+				Name:    "image.upload_progress",
+				Payload: fmt.Sprintf(`{"upload_id":%q,"stage":%q,"detail":%q}`, uploadID, stage, detail),
+			})
+		}
+	}
+
 	_, err = u.ImageSvc.Upload(r.Context(), image.UploadParams{
 		Name:       name,
 		Kind:       kind,
 		Version:    version,
 		ISO:        file,
+		OnProgress: progressFn,
 	})
 	if err != nil {
+		if isXHR {
+			writeJSON(w, http.StatusInternalServerError, map[string]any{"ok": false, "error": err.Error()})
+		} else {
 			renderHTML(w, imageUploadForm(err.Error()))
+		}
 		return
 	}
 
+	if isXHR {
+		writeJSON(w, http.StatusOK, map[string]any{"ok": true})
+	} else {
 		http.Redirect(w, r, "/images", http.StatusSeeOther)
 	}
+}
 
 func (u *UI) SetDefaultImage(w http.ResponseWriter, r *http.Request) {
 	idStr := chi.URLParam(r, "id")

internal/image/extract.go

@@ -15,10 +15,24 @@ type ExtractResult struct {
 	InitrdFilename string
 }
 
+type ProgressFunc func(stage string, detail string)
+
 var kernelCandidates = []string{"linux26", "vmlinuz", "bzImage"}
 var initrdCandidates = []string{"initrd.img", "initrd", "initrd.gz"}
 
 func ExtractFromISO(r io.Reader, destDir string) (*ExtractResult, error) {
+	return ExtractFromISOWithProgress(r, destDir, nil)
+}
+
+func ExtractFromISOWithProgress(r io.Reader, destDir string, progress ProgressFunc) (*ExtractResult, error) {
+	report := func(stage, detail string) {
+		if progress != nil {
+			progress(stage, detail)
+		}
+	}
+
+	report("receiving", "Writing ISO to disk...")
+
 	tmp, err := os.CreateTemp(filepath.Dir(destDir), "iso-upload-*.tmp")
 	if err != nil {
 		return nil, fmt.Errorf("create temp file: %w", err)
@@ -32,6 +46,8 @@ func ExtractFromISO(r io.Reader, destDir string) (*ExtractResult, error) {
 	}
 	tmp.Close()
 
+	report("parsing", "Parsing ISO image...")
+
 	f, err := os.Open(tmpPath)
 	if err != nil {
 		return nil, fmt.Errorf("open temp ISO: %w", err)
@@ -69,13 +85,20 @@ func ExtractFromISO(r io.Reader, destDir string) (*ExtractResult, error) {
 		return nil, fmt.Errorf("no initrd found in ISO (looked for %s)", strings.Join(initrdCandidates, ", "))
 	}
 
+	report("extracting", "Extracting kernel...")
+
 	if err := extractFile(kernelFile, filepath.Join(destDir, kernelName)); err != nil {
 		return nil, fmt.Errorf("extract kernel: %w", err)
 	}
+
+	report("extracting", "Extracting initrd...")
+
 	if err := extractFile(initrdFile, filepath.Join(destDir, initrdName)); err != nil {
 		return nil, fmt.Errorf("extract initrd: %w", err)
 	}
 
+	report("complete", "Extraction complete")
+
 	return &ExtractResult{
 		KernelFilename: kernelName,
 		InitrdFilename: initrdName,

internal/image/service.go

@@ -22,6 +22,7 @@ type UploadParams struct {
 	Kind       string
 	Version    string
 	ISO        io.Reader
+	OnProgress ProgressFunc
 }
 
 var slugRegex = regexp.MustCompile(`^[a-z0-9][a-z0-9.-]*$`)
@@ -46,7 +47,7 @@ func (s *Service) Upload(ctx context.Context, p UploadParams) (*model.Image, err
 		return nil, fmt.Errorf("create image dir: %w", err)
 	}
 
-	result, err := ExtractFromISO(p.ISO, destDir)
+	result, err := ExtractFromISOWithProgress(p.ISO, destDir, p.OnProgress)
 	if err != nil {
 		os.RemoveAll(destDir)
 		return nil, fmt.Errorf("extract ISO: %w", err)

internal/web/static/app.css

@@ -125,3 +125,24 @@ main { padding: 1.5rem; max-width: 1200px; margin: 0 auto; }
 .inline { display: inline; }
 h2 { margin-bottom: 1rem; }
 h3 { margin: 1.5rem 0 0.75rem; color: var(--text-muted); font-size: 0.95rem; }
+
+.upload-progress { max-width: 400px; }
+.progress-bar-track {
+  width: 100%;
+  height: 8px;
+  background: var(--bg);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  margin: 0.75rem 0;
+  overflow: hidden;
+}
+.progress-bar-fill {
+  height: 100%;
+  width: 0%;
+  background: var(--accent);
+  border-radius: 4px;
+  transition: width 0.3s ease;
+}
+.progress-bar-fill.complete { background: var(--green); }
+.progress-text { font-size: 0.85rem; color: var(--text); margin-bottom: 0.25rem; }
+.progress-detail { font-size: 0.8rem; color: var(--text-muted); }

internal/web/static/app.js

@@ -1,18 +1,16 @@
 (function() {
-  const dot = document.getElementById('sse-dot');
+  var dot = document.getElementById('sse-dot');
-  let es;
+  var es;
 
   function connect() {
     es = new EventSource('/events');
-    es.addEventListener('hello', () => {
+    es.addEventListener('hello', function() {
       dot.classList.remove('disconnected');
     });
-    es.addEventListener('host.state_changed', (e) => {
+    es.addEventListener('host.state_changed', function() {
-      // Reload the page to reflect state changes
-      // Future: HTMX swap individual tiles
       window.location.reload();
     });
-    es.onerror = () => {
+    es.onerror = function() {
       dot.classList.add('disconnected');
       es.close();
       setTimeout(connect, 3000);
@@ -21,3 +19,100 @@
 
   connect();
 })();
+
+(function() {
+  var form = document.getElementById('upload-form');
+  if (!form) return;
+
+  var uploadId = 'upload-' + Date.now() + '-' + Math.random().toString(36).substr(2, 9);
+  document.getElementById('upload-id').value = uploadId;
+
+  var progressDiv = document.getElementById('upload-progress');
+  var progressFill = document.getElementById('progress-fill');
+  var progressTitle = document.getElementById('progress-title');
+  var progressText = document.getElementById('progress-text');
+  var progressDetail = document.getElementById('progress-detail');
+
+  var uploadES = new EventSource('/events');
+  uploadES.addEventListener('image.upload_progress', function(e) {
+    var data;
+    try { data = JSON.parse(e.data); } catch(_) { return; }
+    if (data.upload_id !== uploadId) return;
+
+    progressText.textContent = data.detail;
+    if (data.stage === 'parsing' || data.stage === 'extracting') {
+      progressTitle.textContent = 'Extracting boot files...';
+      progressDetail.textContent = 'Processing ISO on server...';
+    }
+    if (data.stage === 'complete') {
+      progressFill.classList.add('complete');
+      progressTitle.textContent = 'Complete';
+      progressDetail.textContent = 'Redirecting...';
+    }
+  });
+
+  form.addEventListener('submit', function(e) {
+    e.preventDefault();
+
+    if (!form.checkValidity()) {
+      form.reportValidity();
+      return;
+    }
+
+    form.style.display = 'none';
+    progressDiv.style.display = 'block';
+
+    var formData = new FormData(form);
+    var xhr = new XMLHttpRequest();
+
+    xhr.upload.addEventListener('progress', function(ev) {
+      if (ev.lengthComputable) {
+        var pct = Math.round((ev.loaded / ev.total) * 100);
+        progressFill.style.width = pct + '%';
+        var mb = (ev.loaded / (1024 * 1024)).toFixed(1);
+        var totalMb = (ev.total / (1024 * 1024)).toFixed(1);
+        progressText.textContent = 'Uploading: ' + mb + ' / ' + totalMb + ' MB (' + pct + '%)';
+      }
+    });
+
+    xhr.upload.addEventListener('load', function() {
+      progressTitle.textContent = 'Processing ISO...';
+      progressText.textContent = 'Upload complete. Extracting kernel and initrd...';
+      progressDetail.textContent = 'This may take a minute...';
+    });
+
+    xhr.addEventListener('load', function() {
+      uploadES.close();
+      var resp;
+      try { resp = JSON.parse(xhr.responseText); } catch(_) { resp = {}; }
+      if (xhr.status >= 200 && xhr.status < 300 && resp.ok) {
+        window.location.href = '/images';
+      } else {
+        progressDiv.style.display = 'none';
+        form.style.display = 'block';
+        showUploadError(resp.error || 'Upload failed');
+      }
+    });
+
+    xhr.addEventListener('error', function() {
+      uploadES.close();
+      progressDiv.style.display = 'none';
+      form.style.display = 'block';
+      showUploadError('Network error during upload');
+    });
+
+    xhr.open('POST', '/images/upload');
+    xhr.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
+    xhr.send(formData);
+  });
+
+  function showUploadError(msg) {
+    var errDiv = form.parentNode.querySelector('.error');
+    if (!errDiv) {
+      errDiv = document.createElement('div');
+      errDiv.className = 'error';
+      form.parentNode.insertBefore(errDiv, form);
+    }
+    errDiv.textContent = msg;
+  }
+})();