wait for server to start before showing view

template/after.sh

+# Wait for the Jupyter Notebook server to start
+echo "Waiting for Jupyter Notebook server to open port ${port}..."
+if wait_until_port_used "${host}:${port}" 60; then
+  echo "Discovered Jupyter Notebook server listening on port ${port}!"
+else
+  echo "Timed out waiting for Jupyter Notebook server to open port ${port}!" ; exit 1
+fi
+sleep 2

view.html.erb

-<p>
-  If you see <code>Failed to connect to ...</code>, then wait a few seconds
-  before trying the <strong>Connect to Jupyter</strong> button again. This
-  warning appeared because the Jupyter Notebook is still starting up.
-</p>
-
 <form action="/node/<%= host %>/<%= port %>/login" method="post" target="_blank">
   <input type="hidden" name="password" value="<%= password %>">
   <button class="btn btn-primary" type="submit">