jupyterhub · yuvipanda · Sep 14, 2020 · Jul 30, 2020 · Aug 3, 2020 · Aug 3, 2020
diff --git a/bootstrap/bootstrap.py b/bootstrap/bootstrap.py
@@ -13,10 +13,13 @@
   - Use stdlib modules only
 """
 import os
+from http.server import SimpleHTTPRequestHandler, HTTPServer
+import multiprocessing
 import subprocess
 import sys
 import logging
 import shutil
+import urllib.request
 
 logger = logging.getLogger(__name__)
 
@@ -90,7 +93,47 @@ def validate_host():
             print("For local development, see http://tljh.jupyter.org/en/latest/contributing/dev-setup.html")
         sys.exit(1)
 
+class LoaderPageRequestHandler(SimpleHTTPRequestHandler):
+    def do_GET(self):
+        if self.path == "/logs":
+            with open("/opt/tljh/installer.log", "rb") as log_file:
+                content = log_file.read()
+                self.wfile.write(content)
+        elif self.path == "/index.html" or self.path == "/favicon.ico":
+            return SimpleHTTPRequestHandler.do_GET(self)
+        elif self.path == "/":
+            self.send_response(302)
+            self.send_header('Location','/index.html')
+            self.end_headers()
+        else:
+            SimpleHTTPRequestHandler.send_error(self, code=403)
+
+def serve_forever(server):
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        pass
+
 def main():
+    temp_page_flag = "--temporary-page"
+    if temp_page_flag in sys.argv:
+        # Serve the loading page until TLJH builds
+        index_url="https://raw.githubusercontent.com/GeorgianaElena/the-littlest-jupyterhub/in-progress-page/bootstrap/index.html"
+        favicon_url="https://raw.githubusercontent.com/jupyterhub/jupyterhub/master/share/jupyterhub/static/favicon.ico"
+        urllib.request.urlretrieve(index_url, "index.html")
+        urllib.request.urlretrieve(favicon_url, "favicon.ico")
+
+        # If the bootstrap is run to upgrade TLJH, then this will raise an "Address already in use" error
+        try:
+            loading_page_server = HTTPServer(("", 80), LoaderPageRequestHandler)
+            p = multiprocessing.Process(target=serve_forever, args=(loading_page_server,))
+            p.start()
+            # Put the pid after the temp page flag to be passed to the istaller
+            sys.argv.insert(sys.argv.index(temp_page_flag)+1, str(p.pid))
+        except OSError:
+            # Only serve the loading page when installing TLJH
+            pass
+
     validate_host()
     install_prefix = os.environ.get('TLJH_INSTALL_PREFIX', '/opt/tljh')
     hub_prefix = os.path.join(install_prefix, 'hub')
@@ -178,6 +221,5 @@ def main():
         ] + sys.argv[1:]
     )
 
-
 if __name__ == '__main__':
     main()
diff --git a/bootstrap/index.html b/bootstrap/index.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<head>
+  <body>
+    <meta http-equiv="refresh" content="30" >
+    <meta http-equiv="content-type" content="text/html; charset=utf-8">
+    <meta name="viewport" content="width=device-width">
+    <img style="width: 150px; height: auto;" src="https://raw.githubusercontent.com/jupyterhub/the-littlest-jupyterhub/master/docs/images/logo/logo.png">
+    <div class="loader center"></div>
+    <div class="center" style="font-size: 30px; font-weight: bold; color: grey; text-align:center;">Please wait while your TLJH is building...</div>
+    <div class="center" style="font-size: 15px; color: grey;">Click the button below to see the logs</div>
+    <div class="center" style="font-size: 13px; color: grey; margin-top: 10px; font-style: italic;">Tip: to update the logs, refresh the page</div>
+    <button class="logs-button center" onclick="window.location.href='/logs'">View logs</button>
+  </body>
+
+  <style>
+    button:hover {
+      background: grey;
+    }
+
+    .center {
+      margin: 0 auto;
+      margin-top: 50px;
+      text-align:center;
+      display: block;
+    }
+    .logs-button {
+      margin-top:15px;
+      border: 0;
+      color: white;
+      padding: 15px 32px;
+      font-size: 16px;
+      cursor: pointer;
+      background: #f5a252;
+    }
+    .loader {
+      width: 150px;
+      height: 150px;
+      border-radius: 90%;
+      border: 7px solid transparent;
+      animation: spin 2s infinite ease;
+      animation-direction: alternate; 
+    }
+    @keyframes spin {
+      0% {
+        transform: rotateZ(0deg);
+        border-top-color: #f17c0e
+      }
+      100% {
+        transform: rotateZ(360deg);
+        border-top-color: #fce5cf;
+      }
+    }
+  </style>
+</head>
diff --git a/tljh/installer.py b/tljh/installer.py
@@ -6,6 +6,7 @@
 import logging
 import os
 import secrets
+import signal
 import subprocess
 import sys
 import time
@@ -485,6 +486,10 @@ def main():
         nargs='*',
         help='Plugin pip-specs to install'
     )
+    argparser.add_argument(
+        '--temporary-page',
+        help='Serve a temporary page while TLJH is building'
+    )
 
     args = argparser.parse_args()
 
@@ -499,6 +504,17 @@ def main():
     ensure_node()
     ensure_jupyterhub_package(HUB_ENV_PREFIX)
     ensure_jupyterlab_extensions()
+
+    # Stop the http server with the loading page before traefik starts
+    if args.temporary_page:
+        try:
+            os.kill(int(args.temporary_page), signal.SIGINT)
+            # Remove the pid file and the temporary html page
+            os.remove('/index.html')
+            os.remove('/favicon.ico')
+        except Exception as e:
+            pass
+
     ensure_jupyterhub_service(HUB_ENV_PREFIX)
     ensure_jupyterhub_running()
     ensure_symlinks(HUB_ENV_PREFIX)