Switch back to using entrypoints to serve desktop-websocket

This is simpler than inheriting from the proxying handler
from jupyter_server_proxy directly, and more importantly keeps
our launcher entry simple and existing!

Author: yuvipanda

js/index.js

@@ -30,8 +30,10 @@ function status(text) {
   document.getElementById("status").textContent = text;
 }
 
-// The websockify URL to connect to is the same URL we are rendering this page on!
-let websockifyUrl = new URL(window.location);
+// This page is served under the /desktop/, and the websockify websocket is served
+// under /desktop-websockify/ with the same base url as /desktop/. We resolve it relatively
+// this way.
+let websockifyUrl = new URL("../desktop-websockify/", window.location);
 websockifyUrl.protocol = window.location.protocol === "https:" ? "wss" : "ws";
 
 // Creating a new RFB object will start a new connection

jupyter_remote_desktop_proxy/handlers.py

@@ -1,10 +1,7 @@
 import os
-import shlex
-import tempfile
-from shutil import which
 
 import jinja2
-from jupyter_server_proxy.handlers import SuperviseAndProxyHandler
+from jupyter_server.base.handlers import JupyterHandler
 from tornado import web
 
 jinja_env = jinja2.Environment(
@@ -17,66 +14,9 @@
 HERE = os.path.dirname(os.path.abspath(__file__))
 
 
-def get_websockify_command():
-    # make a secure temporary directory for sockets
-    # This is only readable, writeable & searchable by our uid
-    sockets_dir = tempfile.mkdtemp()
-    sockets_path = os.path.join(sockets_dir, 'vnc-socket')
-    vncserver = which('vncserver')
-
-    if vncserver is None:
-        # Use bundled tigervnc
-        vncserver = os.path.join(HERE, 'share/tigervnc/bin/vncserver')
-
-    # TigerVNC provides the option to connect a Unix socket. TurboVNC does not.
-    # TurboVNC and TigerVNC share the same origin and both use a Perl script
-    # as the executable vncserver. We can determine if vncserver is TigerVNC
-    # by searching TigerVNC string in the Perl script.
-    with open(vncserver) as vncserver_file:
-        is_tigervnc = "TigerVNC" in vncserver_file.read()
-
-    if is_tigervnc:
-        vnc_args = [vncserver, '-rfbunixpath', sockets_path]
-        socket_args = ['--unix-target', sockets_path]
-    else:
-        vnc_args = [vncserver]
-        socket_args = []
-
-    if not os.path.exists(os.path.expanduser('~/.vnc/xstartup')):
-        vnc_args.extend(['-xstartup', os.path.join(HERE, 'share/xstartup')])
-
-    vnc_command = shlex.join(
-        vnc_args
-        + [
-            '-verbose',
-            '-geometry',
-            '1680x1050',
-            '-SecurityTypes',
-            'None',
-            '-fg',
-        ]
-    )
-
-    return (
-        [
-            'websockify',
-            '-v',
-            '--heartbeat',
-            '30',
-            '{port}',
-        ]
-        + socket_args
-        + ['--', '/bin/sh', '-c', f'cd {os.getcwd()} && {vnc_command}']
-    )
-
-
-class DesktopHandler(SuperviseAndProxyHandler):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.command = get_websockify_command()
-
+class DesktopHandler(JupyterHandler):
     @web.authenticated
-    async def http_get(self, *args, **kwargs):
+    async def get(self):
         template_params = {
             'base_url': self.base_url,
         }

jupyter_remote_desktop_proxy/server_extension.py

@@ -18,12 +18,15 @@ def load_jupyter_server_extension(server_app):
     server_app.web_app.add_handlers(
         ".*",
         [
+            # Serve our own static files
             (
                 url_path_join(base_url, "/desktop/static/(.*)"),
                 AuthenticatedFileHandler,
                 {"path": (str(HERE / "static"))},
             ),
+            # To simplify URL mapping, we make sure that /desktop/ always
+            # has a trailing slash
             (url_path_join(base_url, "/desktop"), AddSlashHandler),
-            (url_path_join(base_url, "/desktop/()"), DesktopHandler, {'state': {}}),
+            (url_path_join(base_url, "/desktop/"), DesktopHandler),
         ],
     )

jupyter_remote_desktop_proxy/setup_websockify.py

@@ -0,0 +1,65 @@
+import os
+import shlex
+import tempfile
+from shutil import which
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+
+
+def setup_websockify():
+    # make a secure temporary directory for sockets
+    # This is only readable, writeable & searchable by our uid
+    sockets_dir = tempfile.mkdtemp()
+    sockets_path = os.path.join(sockets_dir, 'vnc-socket')
+    vncserver = which('vncserver')
+
+    if vncserver is None:
+        # Use bundled tigervnc
+        vncserver = os.path.join(HERE, 'share/tigervnc/bin/vncserver')
+
+    # TigerVNC provides the option to connect a Unix socket. TurboVNC does not.
+    # TurboVNC and TigerVNC share the same origin and both use a Perl script
+    # as the executable vncserver. We can determine if vncserver is TigerVNC
+    # by searching TigerVNC string in the Perl script.
+    with open(vncserver) as vncserver_file:
+        is_tigervnc = "TigerVNC" in vncserver_file.read()
+
+    if is_tigervnc:
+        vnc_args = [vncserver, '-rfbunixpath', sockets_path]
+        socket_args = ['--unix-target', sockets_path]
+    else:
+        vnc_args = [vncserver]
+        socket_args = []
+
+    if not os.path.exists(os.path.expanduser('~/.vnc/xstartup')):
+        vnc_args.extend(['-xstartup', os.path.join(HERE, 'share/xstartup')])
+
+    vnc_command = shlex.join(
+        vnc_args
+        + [
+            '-verbose',
+            '-geometry',
+            '1680x1050',
+            '-SecurityTypes',
+            'None',
+            '-fg',
+        ]
+    )
+
+    return {
+        'command': [
+            'websockify',
+            '-v',
+            '--heartbeat',
+            '30',
+            '{port}',
+        ]
+        + socket_args
+        + ['--', '/bin/sh', '-c', f'cd {os.getcwd()} && {vnc_command}'],
+        'timeout': 30,
+        'new_browser_window': True,
+        # We want the launcher entry to point to /desktop/, not to /desktop-websockify/
+        # /desktop/ is the user facing URL, while /desktop-websockify/ now *only* serves
+        # websockets.
+        "launcher_entry": {"title": "Desktop", "path_info": "desktop"},
+    }

setup.py

@@ -58,7 +58,12 @@ def run(self):
         "Programming Language :: Python :: 3",
     ],
     description="Run a desktop environments on Jupyter",
-    install_requires=[
+    entry_points={
+        'jupyter_serverproxy_servers': [
+            'desktop-websockify = jupyter_remote_desktop_proxy.setup_websockify:setup_websockify',
+        ]
+    },
+    stall_requires=[
         'jupyter-server-proxy>=1.4.0',
     ],
     include_package_data=True,