Allow Werkzeug to be configured to bind to adaptors other than localhost for testing.

web/config.py

@@ -98,6 +98,16 @@ SERVER_MODE = True
 # The default should be fine here, as it's not exposed in the app.
 DESKTOP_USER = 'pgadmin4@pgadmin.org'
 
+# This configuration otion allows the user to host the application on a LAN
+# Default hosting is on localhost (DEFAULT_SERVER='localhost').
+# To host pgAdmin4 over LAN set DEFAULT_SERVER='0.0.0.0' (or a specific
+# adaptor address.
+#
+# NOTE: This is NOT recommended for production use, only for debugging
+# or testing. Production installations should be run as a WSGI application
+# behind Apache HTTPD.
+DEFAULT_SERVER = 'localhost'
+
 # The default port on which the app server will listen if not set in the
 # environment by the runtime
 DEFAULT_SERVER_PORT = 5050

web/pgAdmin4.py

@@ -74,6 +74,8 @@ else:
     server_port = config.DEFAULT_SERVER_PORT
 
 try:
-    app.run(port=server_port, use_reloader=(config.SERVER_MODE and app.debug))
+    app.run(host=config.DEFAULT_SERVER,
+        port=server_port,
+        use_reloader=(config.SERVER_MODE and app.debug))
 except IOError:
     app.logger.error("Error starting the app server: %s", sys.exc_info())