agent-spawner: base64 encoding one more time

The base64 encoding is worth doing on the dispatcher side, and store
strings to Redis, instead of decoding and encoding it once more in
worker (see #155).

Fixes: #155, #156

resalloc_agent_spawner/dispatcher.py

@@ -2,6 +2,7 @@
 Agent spawner daemon.  Part of the resalloc project.
 """
 
+import base64
 import sys
 import logging
 from copr_common.dispatcher import Dispatcher
@@ -84,7 +85,11 @@ def get_ticket_data(self, ticket_id):
         if not ticket.collect():
             # not yet resolved or failed
             return None
-        return ticket.output
+
+        # The ticket.output is bytes(), and we don't plan to touch the data at
+        # all, we are just going to "forward" the data base64 encoded to our
+        # hook scripts.  Encode it now, and never change again.
+        return base64.b64encode(ticket.output).decode("ascii")
 
     def try_to_stop(self, group_id, to_stop):
         """
@@ -174,10 +179,10 @@ def start_preparing(self):
         resource that we can prepare (in the background).  Switch the state.
         """
         for ticket_id in self.get_tickets("NEW"):
-            ticket = self.resalloc.getTicket(ticket_id)
-            if not ticket.collect():
+            data = self.get_ticket_data(ticket_id)
+            if data is None:
                 continue
-            self.set_ticket_attribute(ticket_id, "data", ticket.output)
+            self.set_ticket_attribute(ticket_id, "data", data)
             self.set_ticket_attribute(ticket_id, "state", "PREPARING")
 
     def detect_failed_tickets(self):

resalloc_agent_spawner/worker.py

@@ -2,8 +2,6 @@
 Handle certain tasks by a background daemon process.
 """
 
-import base64
-
 from copr_common.background_worker import BackgroundWorker
 
 from resalloc_agent_spawner.helpers import (
@@ -37,7 +35,9 @@ def handle_ticket(self, ticket_id):
         # We know there's self._redis initialized by parent class so we don't
         # create yet another connection.
         redis_dict = self._redis.hgetall(redis_key)
-        ticket_data = base64.b64encode(redis_dict["data"])
+
+        # dispatcher already converted data to b64-encoded strings
+        ticket_data = redis_dict["data"]
 
         if redis_dict["state"] == "PREPARING":
             if self.cmd_take(redis_dict["group_id"], ticket_data):