From 1099752c900307217d07a17eaf6d9589f7266350 Mon Sep 17 00:00:00 2001
From: Ralph Bean <rbean@redhat.com>
Date: Thu, 30 Jun 2016 13:23:30 -0400
Subject: [PATCH] Also "listen" for messaging.

---
 rida/messaging.py | 22 +++++++++++++++++++++-
 ridad.py          | 18 +++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/rida/messaging.py b/rida/messaging.py
index 5b31b1ec..44eddfee 100644
--- a/rida/messaging.py
+++ b/rida/messaging.py
@@ -25,21 +25,41 @@
 
 
 def publish(topic, msg, backend, modname='rida'):
+    """ Publish a single message to a given backend, and return. """
     try:
         handler = _messaging_backends[backend]['publish']
     except KeyError:
         raise KeyError("No messaging backend found for %r" % backend)
     return handler(topic, msg, modname=modname)
 
+def listen(backend, **kwargs):
+    """ Yield messages from a given messaging backend.
+
+    The ``**kwargs`` arguments will be passed on to the backend to do some
+    backend-specific connection handling, throttling, or filtering.
+    """
+    try:
+        handler = _messaging_backends[backend]['listen']
+    except KeyError:
+        raise KeyError("No messaging backend found for %r" % backend)
+
+    for event in handler(**kwargs):
+        yield event
+
 
 def _fedmsg_publish(topic, msg, modname):
     import fedmsg
     return fedmsg.publish(topic=topic, msg=msg, modname=modname)
 
 
+def _fedmsg_listen(**kwargs):
+    import fedmsg
+    for name, endpoint, topic, msg in fedmsg.tail_messages(**kwargs):
+        yield msg
+
 _messaging_backends = {
     'fedmsg': {
         'publish': _fedmsg_publish,
-        #'listen': _fedmsg_listen,  # For later...
+        'listen': _fedmsg_listen,
     },
 }
diff --git a/ridad.py b/ridad.py
index c7182cc5..430fc094 100755
--- a/ridad.py
+++ b/ridad.py
@@ -23,6 +23,7 @@
 # SOFTWARE.
 #
 # Written by Petr Šabata <contyk@redhat.com>
+#            Ralph Bean <rbean@redhat.com>
 
 """The module build orchestrator for Modularity, the builder.
 
@@ -30,10 +31,25 @@ This is the main component of the orchestrator and is responsible for
 proper scheduling component builds in the supported build systems.
 """
 
-# TODO: Load configuration.
+import rida.config
+import rida.messaging
+
+# TODO: Load the config file from environment
+config = rida.config.from_file("rida.conf")
+
 # TODO: Listen for bus messages from build systems about builds being done.
+for msg in rida.messaging.listen(backend=config.messaging):
+    print("Saw %r with %r" % (msg['topic'], msg))
+    if '.buildsys.build.state.change' in msg['topic']:
+        print("A build changed state in koji!!")
+    elif '.rida.module.state.change' in msg['topic']:
+        print("Our frontend says that a module changed state!!")
+    else:
+        pass
+
 # TODO: Periodically check the state of the build systems' tasks, in case some
 #       messages got lost.
+#       XXX - should we just do this with a cronjob external to this process?
 # TODO: Emit messages about the module build being done.
 # TODO; Watch the database and process modules in the wait state.
 # TODO: Construct the name of the tag/target according to the policy and record