Add Panel dashboard wrapper for Voila (#667)

src/tiledb/cloud/dashboard.py

@@ -0,0 +1,70 @@
+import logging
+import os
+import socket
+from typing import Any
+
+
+def panel_dashboard(
+    app: Any,
+    *,
+    full_screen_link: bool = True,
+    title="Dashboard - TileDB",
+    verbose: bool = False,
+    vh_delta: int = 70,
+) -> Any:
+    """
+    Start a Panel server with the provided app and return an iframe that enables
+    viewing the app in Voila. This wrapper avoids issues with reactive Panel apps
+    in Voila.
+
+    :param app: The Panel app to serve.
+    :param full_screen_link: Include a link to the full screen view, defaults to True.
+    :param title: Title for the Panel server, defaults to "Dashboard - TileDB".
+    :param verbose: Enable verbose logging, defaults to False.
+    :param vh_delta: The vertical height delta for the iframe in px. This value is
+        subtracted from 100vh to set the height of the iframe.
+    :return: A Panel HTML pane containing an iframe that displays the app.
+    """
+
+    # Import Panel here to avoid a dependency on Panel.
+    import panel as pn
+
+    # Get a random open port.
+    with socket.socket() as sock:
+        sock.bind(("localhost", 0))
+        port = sock.getsockname()[1]
+
+    # Reduce noise from the panel server
+    if not verbose:
+        logging.getLogger("bokeh").setLevel(logging.CRITICAL)
+
+    # Start the panel server.
+    pn.serve(
+        app,
+        port=port,
+        address="localhost",
+        show=False,
+        title=title,
+        websocket_origin="*",
+        verbose=verbose,
+    )
+
+    # Create the link for the iframe.
+    if os.getenv("JUPYTERHUB_API_URL"):
+        user = os.getenv("JUPYTERHUB_USER")
+        url = f"/user/{user}/proxy/{port}/"
+    else:
+        url = f"http://localhost:{port}/"
+
+    # Create the iframe.
+    html = (
+        f"<iframe src='{url}' width='100%' "
+        f"style='border: 0;height: calc(100vh - {vh_delta}px);"
+        "margin: 0;'></iframe>"
+    )
+
+    # Add a link to pop out a full screen view.
+    if full_screen_link:
+        html += f"\n<a href='{url}' target='_blank'>Full screen view</a>"
+
+    return pn.pane.HTML(html, sizing_mode="stretch_both")