Rename observer to openstack_observer, making room for more convenient

[plstackapi.git] / planetstack / openstack_observer / event_manager.py

diff --git a/planetstack/openstack_observer/event_manager.py b/planetstack/openstack_observer/event_manager.py
new file mode 100644 (file)
index 0000000..9b02d08
--- /dev/null
+++ b/planetstack/openstack_observer/event_manager.py
@@ -0,0 +1,159 @@
+import threading
+import requests, json
+
+from planetstack.config import Config
+
+import uuid
+import os
+import imp
+import inspect
+import base64
+from fofum import Fofum
+import json
+import traceback
+
+random_client_id=None
+def get_random_client_id():
+    global random_client_id
+
+    if (random_client_id is None) and os.path.exists("/opt/planetstack/random_client_id"):
+        # try to use the last one we used, if we saved it
+        try:
+            random_client_id = open("/opt/planetstack/random_client_id","r").readline().strip()
+            print "get_random_client_id: loaded %s" % random_client_id
+        except:
+            print "get_random_client_id: failed to read /opt/planetstack/random_client_id"
+
+    if random_client_id is None:
+        random_client_id = base64.urlsafe_b64encode(os.urandom(12))
+        print "get_random_client_id: generated new id %s" % random_client_id
+
+        # try to save it for later (XXX: could race with another client here)
+        try:
+            open("/opt/planetstack/random_client_id","w").write("%s\n" % random_client_id)
+        except:
+            print "get_random_client_id: failed to write /opt/planetstack/random_client_id"
+
+    return random_client_id
+
+# decorator that marks dispatachable event methods
+def event(func):
+    setattr(func, 'event', func.__name__)
+    return func
+
+class EventHandler:
+    # This code is currently not in use.
+    def __init__(self):
+        pass
+
+    @staticmethod
+    def get_events():
+        events = []
+        for name in dir(EventHandler):
+            attribute = getattr(EventHandler, name)
+            if hasattr(attribute, 'event'):
+                events.append(getattr(attribute, 'event'))
+        return events
+
+    def dispatch(self, event, *args, **kwds):
+        if hasattr(self, event):
+            return getattr(self, event)(*args, **kwds)
+            
+
+class EventSender:
+    def __init__(self,user=None,clientid=None):
+        try:
+            user = Config().feefie_client_user
+        except:
+            user = 'pl'
+
+        try:
+            clid = Config().feefie_client_id
+        except:
+            clid = get_random_client_id()
+            print "EventSender: no feefie_client_id configured. Using random id %s" % clid
+
+        self.fofum = Fofum(user=user)
+        self.fofum.make(clid)
+
+    def fire(self,**kwargs):
+        kwargs["uuid"] = str(uuid.uuid1())
+        self.fofum.fire(json.dumps(kwargs))
+
+class EventListener:
+    def __init__(self,wake_up=None):
+        self.handler = EventHandler()
+        self.wake_up = wake_up
+        self.deleters = {}
+        self.load_deleter_modules()
+
+    def load_deleter_modules(self, deleter_dir=None):
+        if deleter_dir is None:
+            if hasattr(Config(), "observer_deleters_dir"):
+                deleter_dir = Config().observer_deleters_dir
+            else:
+                deleter_dir = "/opt/planetstack/observer/deleters"
+
+        for fn in os.listdir(deleter_dir):
+            pathname = os.path.join(deleter_dir,fn)
+            if os.path.isfile(pathname) and fn.endswith(".py") and (fn!="__init__.py"):
+                module = imp.load_source(fn[:-3],pathname)
+                for classname in dir(module):
+                    c = getattr(module, classname, None)
+
+                    # make sure 'c' is a descendent of Deleter and has a
+                    # provides field (this eliminates the abstract base classes
+                    # since they don't have a provides)
+
+                    if inspect.isclass(c) and issubclass(c, Deleter) and hasattr(c,"model") and c.model!=None:
+                        modelName = c.model
+                        if not modelName in self.deleters:
+                            self.deleters[modelName] = []
+                        if not (c in self.deleters[modelName]):
+                            self.deleters[modelName].append(c)
+        print 'loaded deleters: %s' % ",".join(self.deleters.keys())
+
+
+    def handle_event(self, payload):
+        payload_dict = json.loads(payload)
+
+        try:
+            deletion = payload_dict.get('delete_flag', False)
+            if (deletion):
+                model = payload_dict['model']
+                pk = payload_dict['pk']
+                model_dict = payload_dict['model_dict']
+
+                for deleter in self.deleters[model]:
+                    try:
+                        deleter()(pk, model_dict)
+                    except:
+                        # something is silently eating these
+                        # exceptions...
+                        traceback.print_exc()
+                        raise
+        except:
+            deletion = False
+
+        if (not deletion and self.wake_up):
+            self.wake_up()
+
+    def run(self):
+        # This is our unique client id, to be used when firing and receiving events
+        # It needs to be generated once and placed in the config file
+
+        try:
+            user = Config().feefie_client_user
+        except:
+            user = 'pl'
+
+        try:
+            clid = Config().feefie_client_id
+        except:
+            clid = get_random_client_id()
+            print "EventListener: no feefie_client_id configured. Using random id %s" % clid
+
+        f = Fofum(user=user)
+        
+        listener_thread = threading.Thread(target=f.listen_for_event,args=(clid,self.handle_event))
+        listener_thread.start()