Support panel fastapi behind reverse proxy

panel/io/location.py

@@ -25,6 +25,46 @@
     from bokeh.server.contexts import BokehSessionContext
     from pyviz_comms import Comm
 
+def _get_location_params(protocol: str|None, host: str| None, uri: str| None)->dict:
+    params = {}
+    href = ''
+    if protocol:
+        params['protocol'] = href = f'{protocol}:'
+    if host:
+        if host.startswith("::ffff:"):
+            host = host.replace("::ffff:", "")
+
+        href += f'//{host}'
+        if ':' in host:
+            params['hostname'], params['port'] = host.split(':')
+        else:
+            params['hostname'] = host
+    if uri:
+        search = hash = None
+
+        if uri.startswith("https,"):
+            uri = uri.replace("https,", "")
+
+        if uri.startswith("http"):
+            uri = urlparse.urlparse(uri).path
+
+        href += uri
+        if '?' in uri and '#' in uri:
+            params['pathname'], query = uri.split('?')
+            search, hash = query.split('#')
+        elif '?' in uri:
+            params['pathname'], search = uri.split('?')
+        elif '#' in uri:
+            params['pathname'], hash = uri.split('#')
+        else:
+            params['pathname'] = uri
+        if search:
+            params['search'] = f'?{search}'
+        if hash:
+            params['hash'] = f'#{hash}'
+    params['href'] = href
+    return params
+
 class Location(Syncable):
     """
     The Location component can be made available in a server context
@@ -70,33 +110,7 @@ def from_request(cls, request):
         except ImportError:
             return cls()
 
-        params = {}
-        href = ''
-        if request.protocol:
-            params['protocol'] = href = f'{request.protocol}:'
-        if request.host:
-            href += f'//{request.host}'
-            if ':' in request.host:
-                params['hostname'], params['port'] = request.host.split(':')
-            else:
-                params['hostname'] = request.host
-        if request.uri:
-            search = hash = None
-            href += request.uri
-            if '?' in request.uri and '#' in request.uri:
-                params['pathname'], query = request.uri.split('?')
-                search, hash = query.split('#')
-            elif '?' in request.uri:
-                params['pathname'], search = request.uri.split('?')
-            elif '#' in request.uri:
-                params['pathname'], hash = request.uri.split('#')
-            else:
-                params['pathname'] = request.uri
-            if search:
-                params['search'] = f'?{search}'
-            if hash:
-                params['hash'] = f'#{hash}'
-        params['href'] = href
+        params = _get_location_params(request.protocol, request.host, request.uri)
         loc = cls()
         with edit_readonly(loc):
             loc.param.update(params)

panel/tests/io/test_location.py

@@ -2,7 +2,7 @@
 import param
 import pytest
 
-from panel.io.location import Location
+from panel.io.location import Location, _get_location_params
 from panel.io.state import state
 from panel.tests.util import serve_and_request, wait_until
 from panel.util import edit_readonly
@@ -188,3 +188,20 @@ def test_location_sync_to_dataframe_with_initial_value(location, dataframe):
     location.search = "?dataframe=%5B%7B%22x%22%3A+1%7D%5D"
     location.sync(p)
     pd.testing.assert_frame_equal(p.dataframe, dataframe)
+
+@pytest.mark.parametrize(("protocol", "host", "uri", "expected"), [
+    # Started with the command fastapi dev script.py on local laptop
+    (
+        "http", "127.0.0.1", "/panel",
+        {'protocol': 'http:', 'hostname': '127.0.0.1', 'pathname': '/panel', 'href': 'http://127.0.0.1/panel'}
+    ),
+    # Started with the command fastapi dev script.py --root-path /some/path in VS Code terminal on JupyterHub
+    (
+        "http", "::ffff:172.20.0.233", "https,http://sub.domain.dk/some/path/panel",
+        # I believe the below should be the result. But do not know for sure
+        {"protocol": "http:", "hostname": "172.20.0.233", "pathname": "/some/path/panel", 'href': 'http://172.20.0.233/some/path/panel'}
+    )
+])
+def test_get_location_params(protocol, host, uri, expected):
+    params = _get_location_params(protocol, host, uri)
+    assert params==expected