Begin draft work to support websocket

First use case will be consoles.

Then we can consider the async case
for smoother async operation as well
though that is less critical.

confluent_server/confluent/httpapi.py

@@ -47,6 +47,7 @@ try:
     import urlparse
 except ModuleNotFoundError:
     import urllib.parse as urlparse
+import eventlet.websocket
 import eventlet.wsgi
 #scgi = eventlet.import_patched('flup.server.scgi')
 tlvdata = confluent.tlvdata
@@ -379,9 +380,48 @@ def _assign_consessionid(consolesession):
                                'expiry': time.time() + 60}
     return sessid
 
+@eventlet.websocket.WebSocketWSGI
+def wsock_handler(ws):
+    sessid = ws.wait()
+    sessid = sessid.replace('ConfluentSessionId:', '')
+    sessid = sessid[:-1]
+    currsess = httpsessions.get(sessid, None)
+    if not currsess:
+        return
+    authtoken = ws.wait()
+    authtoken = authtoken.replace('ConfluentAuthToken:', '')
+    authtoken = authtoken[:-1]
+    if currsess['csrftoken'] != authtoken:
+        return
+    pathrequested = ws.wait()
+    mythreadid = greenlet.getcurrent()
+    httpsessions[sessid]['inflight'].add(mythreadid)
+    name = httpsessions[sessid]['name']
+    authdata = auth.authorize(name, ws.path)
+    if not authdata:
+        return
+    if '/console/session' in ws.path or '/shell/sessions/' in ws.path:
+        #hard bake JSON into this path, do not support other incarnations
+        if '/console/session' in ws.path:
+            prefix, _, _ = ws.path.partition('/console/session')
+            shellsession = False
+        elif '/shell/sessions/' in ws.path:
+            prefix, _, _ = ws.path.partition('/shell/sessions')
+            shellsession = True
+        _, _, nodename = prefix.rpartition('/')
+        # ok, here we need to set up a callback handler
+        # note that currently, it's always json wrapped
+        # it may be wise to send text back straight
+        # for example, could assume our json always has '{'
+        # as the first character, else plain text since it is console
+        # we will loop on ws.wait() to input data, and the data handler
+        # callback will send
+
 
 def resourcehandler(env, start_response):
     try:
+        if 'HTTP_SEC_WEBSOCKET_VERSION' in env:
+            return wsock_handler(env, start_response)
         for rsp in resourcehandler_backend(env, start_response):
             yield rsp
     except Exception as e:
@@ -632,6 +672,8 @@ def resourcehandler_backend(env, start_response):
             sessinfo = {'username': authorized['username']}
             if 'authtoken' in authorized:
                 sessinfo['authtoken'] = authorized['authtoken']
+            if 'sessionid' in authorized:
+                sessinfo['sessionid'] = authorized['sessionid']
             tlvdata.unicode_dictvalues(sessinfo)
             yield json.dumps(sessinfo)
             return