Merge pull request #30 from diggyk/master

Added support for event hooks

bin/hermes-server

@@ -14,6 +14,8 @@ import hermes
 from hermes import version
 from hermes.app import Application
 from hermes.settings import settings
+from hermes.plugin import get_hooks
+from hermes import models
 
 
 from sqlalchemy.exc import OperationalError
@@ -69,6 +71,12 @@ def main():
         "cookie_secret": settings.secret_key,
     }
 
+    # load and register any hooks we have
+    hooks = get_hooks([settings.plugin_dir])
+    for hook in hooks:
+        logging.debug("registering hook {}".format(hook))
+        models.register_hook(hook)
+
     my_settings = {
         "db_uri": settings.database,
         "db_engine": None,

config/dev.yaml

@@ -54,4 +54,7 @@ email_notifications: false
 auth_token_expiry: 600
 
 # Sentry DSN if using Sentry to log exceptions.
-# sentry_dsn:
+# sentry_dsn:
+
+# Additional plugin directory (full path)
+# plugin_dir:

hermes/models.py

@@ -23,6 +23,11 @@
 
 log = logging.getLogger(__name__)
 
+_HOOKS = []
+
+def register_hook(hook):
+    _HOOKS.append(hook)
+
 
 class Session(_Session):
     """ Custom session meant to utilize add on the model.
@@ -827,6 +832,8 @@ def create(
         Returns:
             a newly created Event
         """
+        log.debug("Event.create()")
+
         if host is None:
             raise exc.ValidationError(
                 "Host cannot be null for an event"
@@ -851,12 +858,11 @@ def create(
             session.rollback()
             raise
 
-        # slack_message("*Event:* {} = {} {}".format(
-        #     event.host.hostname,
-        #     event.event_type.category,
-        #     event.event_type.state
-        # ))
+        # if we have any hooks defined, call the on_event method on each
+        for hook in _HOOKS:
+            hook.on_event(event)
 
+        # refer to fates to see if this event should close or open any labors
         Fate.question_the_fates(session, [event], quest=quest)
 
         return event
@@ -872,19 +878,23 @@ def create_many(cls, session, events, tx, quest=None):
             quest: optional if events tied to quests
             flush: indicate if we should flush after we are done
         """
+        log.debug("Event.create_many()")
+
         session.execute(
             Event.__table__.insert(), events
         )
 
         events = session.query(Event).filter(Event.tx == tx).all()
         log.info("Created {} events".format(len(events)))
 
+        for event in events:
+            # if we have any hooks defined, call the on_event method on each
+            for hook in _HOOKS:
+                hook.on_event(event)
 
-        # slack_message("*Events:* created {} events".format(len(events)))
-
+        # refer to fates to see if these events should close or open any labors
         Fate.question_the_fates(session, events, quest=quest)
 
-
     def href(self, base_uri):
         """Create an HREF value for this object
 

hermes/plugin.py

@@ -0,0 +1,40 @@
+"""
+Module for declaring plugin base classes and helpers.
+"""
+
+import annex
+import os
+import logging
+
+BUILTIN_PLUGIN_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "plugins")
+
+log = logging.getLogger(__name__)
+
+class BaseHermesHook(object):
+    """ Base class for adding hooks into Hermes.
+
+        This class must be overridden to add actions to perform before and
+        after particular state transitions in Hermes.
+    """
+
+    def on_event(self, event):
+        """Called when an event is created.
+
+        Args:
+            event: the event that was created
+        """
+
+
+def get_hooks(additional_dirs=None):
+    """ Helper function to find and load all hooks. """
+    log.debug("get_hooks()")
+    if additional_dirs is None:
+        additional_dirs = []
+    hooks = annex.Annex(BaseHermesHook, [
+        os.path.join(BUILTIN_PLUGIN_DIR, "hooks"),
+        "/etc/hermes/plugins/hooks",
+        [os.path.expanduser(os.path.join(plugin_dir, "hooks"))
+         for plugin_dir in additional_dirs]
+        ], instantiate=True)
+
+    return hooks

hermes/plugins/__init__.py

@@ -0,0 +1 @@
+__author__ = 'digant'

hermes/plugins/hooks/__init__.py

@@ -0,0 +1 @@
+__author__ = 'digant'

hermes/settings.py

@@ -62,4 +62,5 @@ def __getattr__(self, name):
     "secret_key": "SECRET_KEY",
     "auth_token_expiry": 600,  # 10 minutes
     "sentry_dsn": None,
+    "plugin_dir": "plugins ",
 })

hermes/version.py

@@ -1 +1 @@
-__version__ = "0.2.4"
+__version__ = "0.2.6"

requirements.txt

@@ -20,3 +20,4 @@ tornado==4.0.2
 MySQL-python==1.2.5
 requests[security]==2.7.0
 python-dateutil==2.4.2
+annex==0.3.1