add X-Origin to GET requests, so isso.dispatch works on a single host

dispatch.py

@@ -7,6 +7,7 @@ try:
 except ImportError:
     from urllib.parse import urlparse
 
+from werkzeug.wrappers import Request
 from werkzeug.exceptions import ImATeapot
 
 from isso import make_app, wsgi
@@ -34,13 +35,13 @@ class Dispatcher(object):
 
     def __call__(self, environ, start_response):
 
-        if "HTTP_ORIGIN" in environ:
-            origin = environ["HTTP_ORIGIN"]
-        elif "HTTP_REFERER" in environ:
-            rv = urlparse(environ["HTTP_REFERER"])
-            origin = rv.scheme + "://" + rv.hostname + (":" + str(rv.port) if rv.port else "")
-        else:
-            origin = wsgi.host(environ)
+        if Request(environ).url.endswith((".js", ".css")):
+            return self.isso.values()[0](environ, start_response)
+
+        if "HTTP_X_ORIGIN" in environ and "HTTP_ORIGIN" not in environ:
+            environ["HTTP_ORIGIN"] = environ["HTTP_X_ORIGIN"]
+
+        origin = environ.get("HTTP_ORIGIN", wsgi.host(environ))
 
         try:
             # logger.info("dispatch %s", origin)

docs/CONFIGURATION.rst

@@ -216,11 +216,9 @@ comments for a relative URL to support HTTP, HTTPS and even domain transfers
 without manual intervention. But you can chain Isso to support multiple
 websites on different domains.
 
-The following example uses `gunicorn <http://gunicorn.org/>`_ as WSGI server (you
-can use uWSGI as well). It is *not* possible to run the isso executable for
-multiple sites.
-
-Let's say you maintain two websites, like foo.example and other.foo:
+The following example uses `gunicorn <http://gunicorn.org/>`_ as WSGI server (
+you can use uWSGI as well). Let's say you maintain two websites, like
+foo.example and other.foo:
 
 .. code-block:: bash
 
@@ -234,67 +232,38 @@ Let's say you maintain two websites, like foo.example and other.foo:
     host = http://other.foo/
     dbpath = /var/lib/isso/other.foo.db
 
-Then you run Isso with gunicorn like this:
+Then you run Isso using gunicorn:
 
 .. code-block:: bash
 
     $ export ISSO_SETTINGS="/etc/isso.d/foo.example.cfg;/etc/isso.d/other.foo.cfg"
     $ gunicorn isso.dispatch -b localhost:8080
 
-Now, there are two options to configure the webserver:
-
-1. using a single host to serve comments for both websites
-2. different hosts for both websites
-
-In the former case, Isso dispatches based on the HTTP Referer and (if provided)
-HTTP Origin. If you expect users to supress their referer completely, you
-should use the second option.
-
-1. Using a single host to serve comments.
-
-   .. code-block:: nginx
+In your webserver configuration, proxy Isso as usual:
 
-         server {
-             listen [::]:80;
-             server_name comments.example;
+.. code-block:: nginx
 
-             location / {
-                 proxy_pass http://localhost:8080;
-                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-                 proxy_set_header X-Real-IP $remote_addr;
-             }
-         }
+      server {
+          listen [::]:80;
+          server_name comments.example;
 
-   To verify the setup, run:
+          location / {
+              proxy_pass http://localhost:8080;
+              proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+              proxy_set_header X-Real-IP $remote_addr;
+          }
+      }
 
-   .. code-block:: bash
+To verify the setup, run:
 
-         $ curl -vH "Origin: http://foo.example" http://comments.example/
-         ...
-         $ curl -vH "Origin: http://other.foo" http://comments.example/
-         ...
-
-   In case of a 418 (I'm a teapot), the setup is *not* correctly configured.
-
-2. Using different hosts for both websites (no need for a dedicated domain,
-   you can also proxy Isso on a sub-uri like /isso).
-
-   .. code-block:: nginx
-
-         server {
-             listen [::]:80;
-             server_name comments.foo.example comments.other.foo;
+.. code-block:: bash
 
-             location / {
-                 proxy_pass http://localhost:8080;
-                 proxy_set_header Host $host;
-                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-                 proxy_set_header X-Real-IP $remote_addr;
-             }
-         }
+      $ curl -vH "Origin: http://foo.example" http://comments.example/
+      ...
+      $ curl -vH "Origin: http://other.foo" http://comments.example/
+      ...
 
-   No need to verify this setup, here the webserver automatically sets the
-   proper host.
+In case of a 418 (I'm a teapot), the setup is *not* correctly configured.
 
 
 Appendum

isso/js/app/api.js

@@ -92,7 +92,12 @@ define(["q"], function(Q) {
 
         try {
             xhr.open(method, url, true);
-            xhr.withCredentials = true;  // fuck you, fuck you, fuck you IE
+            xhr.withCredentials = true;
+
+            if (method === "GET") {
+                xhr.setRequestHeader("X-Origin", window.location.origin);
+            }
+
             xhr.onreadystatechange = function () {
                 if (xhr.readyState === 4) {
                     onload();

isso/wsgi.py

@@ -59,7 +59,7 @@ class CORSMiddleware(object):
         def add_cors_headers(status, headers, exc_info=None):
             headers = Headers(headers)
             headers.add("Access-Control-Allow-Origin", self.origin(environ))
-            headers.add("Access-Control-Allow-Headers", "Origin, Content-Type")
+            headers.add("Access-Control-Allow-Headers", "Origin, Content-Type, X-Origin")
             headers.add("Access-Control-Allow-Credentials", "true")
             headers.add("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE")
             headers.add("Access-Control-Expose-Headers", "X-Set-Cookie")