Add several tokens to control events between resources

docs/events.md

@@ -24,11 +24,11 @@ Propagating events when there is no data changed
 
 Control for specifying events:
 
-  on <emitter>.<emmiter_action> <event> <subscriber>.<subsciber_action>
+on <emitter>.<emmiter_action> <event> <subscriber>.<subsciber_action>
 
-# on mariadb.run                changed keystone.run
-# on keystone.run               changed keystone_config.run
-# on keystone_config.run        changed haproxy.reload
+on mariadb.run                changed keystone.run
+on keystone.run               changed keystone_config.run
+on keystone_config.run        changed haproxy.reload
 
 +---------------------+
 |     mariadb.run     |
@@ -46,13 +46,13 @@ Control for specifying events:
 |   haproxy.reload    |
 +---------------------+
 
-<u> - <event>:<action> - <v>
+<u>.<action> - <event> - <v>.<action>
 
-When connection between several resources created - events connections should
+When data connection between several resources created - events connections should
 be created as well, resource a connect resource b:
 
-on a changed b reload
-on a removed b run
+on a.run    changed b.reload
+on a.remove changed b.run
 
 -------------------------------------------------
 Resolving cycles on a data plane
@@ -73,9 +73,9 @@ rmq.2.cluster_join, rmq.2.cluster_join
 
 Also cluster operation should happen only when rmq.cluster is changed.
 
-on rmq.cluster changed rmq.1 cluster_create
-on rmq.1.cluster_create changed rmq.2 cluster_join
-on rmq.1.cluster_create changed rmq.3 cluster_join
+on rmq.cluster          changed rmq.1.cluster_create
+on rmq.1.cluster_create changed rmq.2.cluster_join
+on rmq.1.cluster_create changed rmq.3.cluster_join
 
 +----------------------+
 |      rmq.1.run       |
@@ -102,7 +102,7 @@ on rmq.1.cluster_create changed rmq.3 cluster_join
 |      rmq.3.run       |  |
 +----------------------+  |
   |                       |
-  | cahnged               |
+  | changed               |
   v                       |
 +----------------------+  |
 |  rmq.3.cluster_join  | <+
@@ -113,7 +113,7 @@ on rmq.1.cluster_create changed rmq.3 cluster_join
 ---------------------------------------------------
 Resolve cycles on a execution level
 
-Lets say we have 5 objects, which forms 2 pathes
+We have 5 objects, which forms 2 pathes
 - keystone-config -> keystone-service -> haproxy-sevice
 - glance-config -> glance-service -> haproxy-service
 

solar/solar/events/control.py

@@ -0,0 +1,75 @@
+"""
+Available controls:
+
+*depends_on* implements relationship that will guarantee that depended action
+on resource will be executed after parent, if parent will be executed. It means
+that this control contributes only to ordering, and wont trigger any action
+if dependent resource isnt changed.
+
+    depends_on:
+        - parent:run -> ok -> dependent:run
+
+*react_on* - relationship which will guarantee that action on dependent resource
+will be executed if parent action is going to be executed. This control will
+trigger action even if no changes noticed on dependent resource.
+
+    react_on:
+        - parent:update -> ok -> dependent:update
+"""
+
+import re
+
+from solar.core.log import log
+
+
+EVENT = re.compile(r'\s+->\s+')
+
+
+class Event(object):
+
+    def __init__(self, event):
+        self.parent, self.dependent, self.state = EVENT.split(event)
+        self.parent_node, self.parent_action = self.parent.split(':')
+        self.dep_node, self.dep_action = self.dependent.split(':')
+
+    def __repr__(self):
+        return '{}({} -> {} -> {})'.format(
+            self.__class__.__name__,
+            self.parent, self.dependent, self.state)
+
+
+class Dependency(Event):
+
+    def add(self, changed_resources, changes_graph):
+        if self.parent in changes_graph:
+            changes_graph.add_edge(
+                self.parent, self.dependent, state=self.state)
+
+
+class React(Event):
+
+    def add(self, changed_resources, changes_graph):
+        changes_graph.add_edge(self.parent, self.dependent, state=self.state)
+        changed_resources.append(self.dep_node)
+
+
+def build_edges(changed_resources, changes_graph, events):
+    """
+    :param changed_resources: list of resource names that were changed
+    :param changes_graph: nx.DiGraph object with actions to be executed
+    :param events:
+    """
+    stack = changed_resources[:]
+    while stack:
+        node = stack.pop()
+        events_objects = []
+
+        if node in events:
+            log.debug('Events %s for resource %s', events[node], node)
+
+            for e in events[node].get('react_on', ()):
+                React(e).add(stack, changes_graph)
+            for e in events[node].get('depends_on', ()):
+                Dependency(e).add(stack, changes_graph)
+
+    return changes_graph

solar/solar/interfaces/db/redis_db.py

@@ -10,7 +10,7 @@ from solar import errors
 class RedisDB(object):
     COLLECTIONS = Enum(
         'Collections',
-        'connection resource state_data state_log'
+        'connection resource state_data state_log events'
     )
     DB = {
         'host': 'localhost',

solar/solar/test/test_events.py

@@ -3,6 +3,7 @@ import networkx as nx
 from pytest import fixture
 
 
+
 @fixture
 def simple():
     dg = nx.DiGraph()
@@ -10,24 +11,29 @@ def simple():
     dg.add_edge('keystone_config.run', 'haproxy.reload', event='changed')
     return dg
 
+
 def test_simple(simple):
-    nx.write_dot(simple, 'simple.dot')
+    pass
+
 
 
 @fixture
 def rmq():
     """Example of a case when we have cycles on a data plane."""
     dg = nx.DiGraph()
-    dg.add_edge('rmq.1.run', 'rmq.1.cluster_create', event='changed')
-    dg.add_edge('rmq.1.cluster_create', 'rmq.2.cluster_join', event='changed')
-    dg.add_edge('rmq.1.cluster_create', 'rmq.3.cluster_join', event='changed')
-    dg.add_edge('rmq.2.run', 'rmq.2.cluster_join', event='changed')
-    dg.add_edge('rmq.3.run', 'rmq.3.cluster_join', event='changed')
+    dg.add_edge('rmq_cluster.run', 'rmq_cluster.1.create', event='changed')
+    dg.add_edge('rmq_cluster.run', 'rmq_cluster.2.join', event='changed')
+    dg.add_edge('rmq_cluster.run', 'rmq_cluster.3.join', event='changed')
+    dg.add_edge('rmq.1.run', 'rmq_cluster.1.create', event='changed')
+    dg.add_edge('rmq.2.run', 'rmq_cluster.2.join', event='changed')
+    dg.add_edge('rmq.3.run', 'rmq_cluster.3.join', event='changed')
+    dg.add_edge('rmq_cluster.1.create', 'rmq_cluster.2.join', event='changed')
+    dg.add_edge('rmq_cluster.1.create', 'rmq_cluster.3.join', event='changed')
     return dg
 
 
 def test_rmq(rmq):
-    nx.write_dot(rmq, 'rmq.dot')
+    pass
 
 
 @fixture
@@ -43,4 +49,4 @@ def haproxy():
 
 
 def test_haproxy(haproxy):
-    nx.write_dot(haproxy, 'haproxy.dot')
+    pass