app: allow http requests to specifiy a websocket id

Some requests, such "printer/objects/subscribe", require a websocket
for asynchronous updates.  Clients may now specify a "connection_id"
in the form data that identifies an associated websocket.

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

moonraker/app.py

@@ -270,12 +270,13 @@ class RemoteRequestHandler(AuthorizedRequestHandler):
         await self._process_http_request()
 
     async def _process_http_request(self):
+        conn = self.get_associated_websocket()
         args = {}
         if self.request.query:
             args = self.query_parser(self.request)
         try:
             result = await self.server.make_request(
-                WebRequest(self.remote_callback, args))
+                WebRequest(self.remote_callback, args, conn=conn))
         except ServerError as e:
             raise tornado.web.HTTPError(
                 e.status_code, str(e)) from e
@@ -307,12 +308,13 @@ class LocalRequestHandler(AuthorizedRequestHandler):
             raise tornado.web.HTTPError(405)
 
     async def _process_http_request(self, method):
+        conn = self.get_associated_websocket()
         args = {}
         if self.request.query:
             args = self.query_parser(self.request)
         try:
             result = await self.callback(
-                WebRequest(self.request.path, args, method))
+                WebRequest(self.request.path, args, method, conn=conn))
         except ServerError as e:
             raise tornado.web.HTTPError(
                 e.status_code, str(e)) from e

moonraker/authorization.py

@@ -208,6 +208,20 @@ class AuthorizedRequestHandler(tornado.web.RequestHandler):
         else:
             super(AuthorizedRequestHandler, self).options()
 
+    def get_associated_websocket(self):
+        # Return associated websocket connection if an id
+        # was provided by the request
+        conn = None
+        conn_id = self.get_argument('connection_id', None)
+        if conn_id is not None:
+            try:
+                conn_id = int(conn_id)
+            except Exception:
+                pass
+            else:
+                conn = self.wsm.get_websocket(conn_id)
+        return conn
+
 # Due to the way Python treats multiple inheritance its best
 # to create a separate authorized handler for serving files
 class AuthorizedFileHandler(tornado.web.StaticFileHandler):