cycle detection when multiple parents

awx/api/views/__init__.py

@@ -87,6 +87,7 @@ from awx.api.renderers import * # noqa
 from awx.api.serializers import * # noqa
 from awx.api.metadata import RoleMetadata, JobTypeMetadata
 from awx.main.constants import ACTIVE_STATES
+from awx.main.scheduler.dag_workflow import WorkflowDAG
 from awx.api.views.mixin import (
     ActivityStreamEnforcementMixin,
     SystemTrackingEnforcementMixin,
@@ -143,6 +144,9 @@ from awx.api.views.root import ( # noqa
 )
 
 
+logger = logging.getLogger('awx.api.views')
+
+
 def api_exception_handler(exc, context):
     '''
     Override default API exception handler to catch IntegrityError exceptions.
@@ -2950,33 +2954,17 @@ class WorkflowJobTemplateNodeChildrenBaseList(WorkflowsEnforcementMixin, Enforce
         if created:
             return None
 
-        workflow_nodes = parent.workflow_job_template.workflow_job_template_nodes.all().\
-            prefetch_related('success_nodes', 'failure_nodes', 'always_nodes')
-        graph = {}
-        for workflow_node in workflow_nodes:
-            graph[workflow_node.pk] = dict(node_object=workflow_node, metadata={'parent': None, 'traversed': False})
+        if parent.id == sub.id:
+            return {"Error": _("Cycle detected.")}
 
-        find = False
-        for node_type in ['success_nodes', 'failure_nodes', 'always_nodes']:
-            for workflow_node in workflow_nodes:
-                parent_node = graph[workflow_node.pk]
-                related_nodes = getattr(parent_node['node_object'], node_type).all()
-                for related_node in related_nodes:
-                    sub_node = graph[related_node.pk]
-                    sub_node['metadata']['parent'] = parent_node
-                    if not find and parent == workflow_node and sub == related_node and self.relationship == node_type:
-                        find = True
-        if not find:
-            sub_node = graph[sub.pk]
-            parent_node = graph[parent.pk]
-            sub_node['metadata']['parent'] = parent_node
-            iter_node = sub_node
-            while iter_node is not None:
-                if iter_node['metadata']['traversed']:
-                    return {"Error": _("Cycle detected.")}
-                iter_node['metadata']['traversed'] = True
-                iter_node = iter_node['metadata']['parent']
+        parent_node_type_relationship = getattr(parent, self.relationship)
+        parent_node_type_relationship.add(sub)
+        parent.save()
 
+        graph = WorkflowDAG(parent.workflow_job_template)
+        if graph.has_cycle():
+            parent_node_type_relationship.remove(sub)
+            return {"Error": _("Cycle detected.")}
         return None
 
 

awx/main/scheduler/dag_simple.py

@@ -23,9 +23,9 @@ class SimpleDAG(object):
         def run_status(obj):
             dnr = "RUN"
             status = "NA"
-            if obj.job:
+            if hasattr(obj, 'job') and obj.job and hasattr(obj.job, 'status'):
                 status = obj.job.status
-            if obj.do_not_run is True:
+            if hasattr(obj, 'do_not_run') and obj.do_not_run is True:
                 dnr = "DNR"
             return "{}_{}_{}".format(dnr, status, obj.id)
 
@@ -36,7 +36,7 @@ class SimpleDAG(object):
         for n in self.nodes:
             obj = n['node_object']
             status = "NA"
-            if obj.job:
+            if hasattr(obj, 'job') and obj.job:
                 status = obj.job.status
             color = 'black'
             if status == 'successful':
@@ -65,8 +65,12 @@ class SimpleDAG(object):
     def add_edge(self, from_obj, to_obj, label=None):
         from_obj_ord = self.find_ord(from_obj)
         to_obj_ord = self.find_ord(to_obj)
-        if from_obj_ord is None or to_obj_ord is None:
-            raise LookupError("Object not found")
+        if from_obj_ord is None and to_obj_ord is None:
+            raise LookupError("From object {} and to object not found".format(from_obj, to_obj))
+        elif from_obj_ord is None:
+            raise LookupError("From object not found {}".format(from_obj))
+        elif to_obj_ord is None:
+            raise LookupError("To object not found {}".format(to_obj))
         self.edges.append((from_obj_ord, to_obj_ord, label))
 
     def add_edges(self, edgelist):
@@ -116,3 +120,29 @@ class SimpleDAG(object):
             if len(self.get_dependents(n['node_object'])) < 1:
                 roots.append(n)
         return roots
+
+    def has_cycle(self):
+        node_objs = [node['node_object'] for node in self.get_root_nodes()]
+        nodes_visited = set([])
+        path = set([])
+        stack = node_objs
+        path_direction = 'DOWN'
+
+        while stack:
+            node_obj = stack.pop()
+
+            children = self.get_dependencies(node_obj)
+            for child in children:
+                if child['node_object'] not in nodes_visited:
+                    stack.append(child['node_object'])
+            if node_obj in path:
+                return True
+
+            if not children:
+                path_direction = 'UP'
+
+            if path_direction == 'DOWN':
+                path.add(node_obj)
+            elif path_direction == 'UP':
+                path.discard(node_obj)
+        return False

awx/main/scheduler/dag_workflow.py

@@ -12,8 +12,14 @@ class WorkflowDAG(SimpleDAG):
         if workflow_job:
             self._init_graph(workflow_job)
 
-    def _init_graph(self, workflow_job):
-        node_qs = workflow_job.workflow_job_nodes
+    def _init_graph(self, workflow_job_or_jt):
+        if hasattr(workflow_job_or_jt, 'workflow_job_template_nodes'):
+            node_qs = workflow_job_or_jt.workflow_job_template_nodes
+        elif hasattr(workflow_job_or_jt, 'workflow_job_nodes'):
+            node_qs = workflow_job_or_jt.workflow_job_nodes
+        else:
+            raise RuntimeError("Unexpected object {} {}".format(type(workflow_job_or_jt), workflow_job_or_jt))
+
         workflow_nodes = node_qs.prefetch_related('success_nodes', 'failure_nodes', 'always_nodes').all()
         for workflow_node in workflow_nodes:
             self.add_node(workflow_node)