Some structure for event handling in ridad.py.

rida/scheduler/main.py

@@ -29,6 +29,8 @@ This is the main component of the orchestrator and is responsible for
 proper scheduling component builds in the supported build systems.
 """
 
+
+import inspect
 import logging
 import os
 import threading
@@ -36,6 +38,8 @@ import threading
 import rida.config
 import rida.messaging
 
+import koji
+
 log = logging.getLogger()
 
 # TODO: Load the config file from environment
@@ -47,22 +51,50 @@ config = rida.config.from_file("rida.conf")
 # TODO: Set the build state to failed if the module build fails.
 
 class Messaging(threading.Thread):
+    on_build_change = {
+        koji.BUILD_STATES["BUILDING"]: lambda x: x
+    }
+    on_module_change = {
+        rida.BUILD_STATES["new"]: rida.scheduler.handlers.modules.new,
+    }
+    def sanity_check(self):
+        """ On startup, make sure our implementation is sane. """
+        # Ensure we have every state covered
+        for state in rida.BUILD_STATES:
+            if state not in self.on_module_change:
+                raise KeyError("Module build states %r not handled." % state)
+        for state in koji.BUILD_STATES:
+            if state not in self.on_build_change:
+                raise KeyError("Koji build states %r not handled." % state)
+
+        all_fns = self.on_build_change.items() + self.on_module_change.items()
+        for key, callback in all_fns:
+            expected = ['conf', 'db', 'msg']
+            argspec = inspect.getargspec(callback)
+            if argspec != expected:
+                raise ValueError("Callback %r, state %r has argspec %r!=%r" % (
+                    callback, key, argspec, expected))
+
     def run(self):
-        # TODO: Listen for bus messages from rida about module builds
-        #       entering the wait state
-        # TODO: Listen for bus messages from the buildsystem about
-        #       component builds changing state
+        self.sanity_check()
         # TODO: Check for modules that can be set to done/failed
         # TODO: Act on these things somehow
         # TODO: Emit messages about doing so
         for msg in rida.messaging.listen(backend=config.messaging):
             log.debug("Saw %r, %r" % (msg['msg_id'], msg['topic']))
+
+            # Choose a handler for this message
             if '.buildsys.build.state.change' in msg['topic']:
-                self.handle_build_change(msg)
+                handler = self.on_build_change[msg['msg']['new']]
             elif '.rida.module.state.change' in msg['topic']:
-                self.handle_module_change(msg)
+                handler = self.on_module_change[msg['msg']['state']]
             else:
-                pass
+                log.debug("Unhandled message...")
+                continue
+
+            # Execute our chosen handler
+            with rida.Database(config) as session:
+                handler(config, session, msg)
 
 class Polling(threading.Thread):
     def run(self):