From 321fdf89b474a0ef01be637a52e26afc38b30998 Mon Sep 17 00:00:00 2001
From: Florian Bezannier <florian.bezannier@hotmail.fr>
Date: Wed, 16 Jun 2021 13:21:52 +0200
Subject: [PATCH] fix ingress

---
 web/app.py         | 29 +++++++++++++++++++++--------
 web/dash_custom.py | 28 ++++++++++++++++++++++++++++
 web/views.py       |  3 ++-
 3 files changed, 51 insertions(+), 9 deletions(-)
 create mode 100644 web/dash_custom.py

diff --git a/web/app.py b/web/app.py
index 140f10a..249f23e 100644
--- a/web/app.py
+++ b/web/app.py
@@ -1,12 +1,12 @@
 import locale
 
-import dash
 import dash_bootstrap_components as dbc
 from flask import Flask
-
 from werkzeug import run_simple
 from werkzeug.middleware.proxy_fix import ProxyFix
 
+from web.dash_custom import DashCustom
+
 try:
     from werkzeug.middleware.dispatcher import DispatcherMiddleware
 except ImportError:
@@ -22,13 +22,26 @@ dispatcher = None
 
 
 class MyProxyFix(ProxyFix):
+    def __init__(self, dashapp):
+        self.flask_app = dashapp.server
+        self.dash_app = dash_app
+        super().__init__(self.flask_app.wsgi_app, x_host=1, x_port=1, x_prefix=1)
+
     def __call__(self, environ, start_response):
-        ingress_path = environ.get("HTTP_X_INGRESS_PATH")
-        if ingress_path:
-            environ["HTTP_X_FORWARDED_PREFIX"] = ingress_path
+        prefix = environ.get("HTTP_X_INGRESS_PATH")
+        if prefix:
+            environ["HTTP_X_FORWARDED_PREFIX"] = prefix
+            self.flask_app.config['APPLICATION_ROOT'] = environ['SCRIPT_NAME'] = prefix
+            prefix += "/"
+            self.dash_app.requests_pathname_external_prefix = prefix
+            self.dash_app.config.assets_external_path = prefix
+        else:
+            self.flask_app.config['APPLICATION_ROOT'] = "/"
+            self.dash_app.requests_pathname_external_prefix = "/"
         return super().__call__(environ, start_response)
 
 
+
 def start_app(*args, **kwargs):
     run(config_flask(*args, **kwargs))
 
@@ -47,7 +60,6 @@ def config_flask(title, base_path, debug: bool, host, port, reloader=False,  # p
         logger.warning("Can't get language")
     if unminified:
         locale_url = ["assets/plotly-with-meta.js"]
-    app.wsgi_app = MyProxyFix(app.wsgi_app, x_prefix=1)
     app.config["DEBUG"] = debug
     if base_path == "/":
         application = DispatcherMiddleware(app)
@@ -55,10 +67,11 @@ def config_flask(title, base_path, debug: bool, host, port, reloader=False,  # p
     else:
         application = DispatcherMiddleware(Flask('dummy_app'), {base_path: app})
         requests_pathname_prefix = base_path + "/"
-    dash_app = dash.Dash(external_stylesheets=[dbc.themes.BOOTSTRAP], external_scripts=locale_url, title=title,
+    dash_app = DashCustom(external_stylesheets=[dbc.themes.BOOTSTRAP], external_scripts=locale_url, title=title,
                          server=app, requests_pathname_prefix=requests_pathname_prefix,
-                         suppress_callback_exceptions=True)
+                         suppress_callback_exceptions=True, serve_locally=False)
     dash_app.enable_dev_tools(reloader)
+    app.wsgi_app = MyProxyFix(dash_app)
     # keep this line
     importlib.import_module(view)
     if reload_view:
diff --git a/web/dash_custom.py b/web/dash_custom.py
new file mode 100644
index 0000000..5f9d143
--- /dev/null
+++ b/web/dash_custom.py
@@ -0,0 +1,28 @@
+from dash import Dash
+
+class DashCustom(Dash):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.requests_pathname_external_prefix = self.config.requests_pathname_prefix
+
+    def _config(self):
+        # pieces of config needed by the front end
+        config = {
+            "url_base_pathname": self.config.url_base_pathname,
+            "requests_pathname_prefix": self.requests_pathname_external_prefix,
+            "ui": self._dev_tools.ui,
+            "props_check": self._dev_tools.props_check,
+            "show_undo_redo": self.config.show_undo_redo,
+            "suppress_callback_exceptions": self.config.suppress_callback_exceptions,
+            "update_title": self.config.update_title,
+        }
+        if self._dev_tools.hot_reload:
+            config["hot_reload"] = {
+                # convert from seconds to msec as used by js `setInterval`
+                "interval": int(self._dev_tools.hot_reload_interval * 1000),
+                "max_retry": self._dev_tools.hot_reload_max_retry,
+            }
+        if self.validation_layout and not self.config.suppress_callback_exceptions:
+            config["validation_layout"] = self.validation_layout
+
+        return config
diff --git a/web/views.py b/web/views.py
index fcd2143..82d09fd 100644
--- a/web/views.py
+++ b/web/views.py
@@ -42,12 +42,13 @@ CONFIG = Config()
 @dash_app.callback(Output('page-content', 'children'),
                    [Input('url', 'pathname')])
 def display_page(pathname):
+    pathname = pathname[len(dash_app.requests_pathname_external_prefix)-1:]
     if pathname == "/config":
         return config_layout
     if pathname == "/log":
         return log_layout()
     if not CONFIG.is_good:
-        return dcc.Location(pathname="/config", id="config_redirect")
+        return dcc.Location(pathname=dash_app.requests_pathname_external_prefix + "config", id="config_redirect")
     if pathname == "/config_otp":
         return config_otp_layout
     return serve_layout()