From 880341ac05a6578e8d5746354fc169dca74f3a58 Mon Sep 17 00:00:00 2001
From: AlanCoding <arominge@redhat.com>
Date: Fri, 5 Apr 2019 13:10:08 -0400
Subject: [PATCH 1/2] avoid slicing if the inventory only has 1 host

---
 awx/main/models/inventory.py                 |  2 +-
 awx/main/models/jobs.py                      | 20 ++++++++++++--------
 awx/main/tests/functional/models/test_job.py | 12 +++++++++++-
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/awx/main/models/inventory.py b/awx/main/models/inventory.py
index 6004bebba4..dab2b395dc 100644
--- a/awx/main/models/inventory.py
+++ b/awx/main/models/inventory.py
@@ -256,7 +256,7 @@ class Inventory(CommonModelNameNotUnique, ResourceMixin, RelatedJobsMixin):
         if towervars:
             fetch_fields.append('enabled')
         hosts = self.hosts.filter(**hosts_kw).order_by('name').only(*fetch_fields)
-        if slice_count > 1:
+        if slice_count > 1 and slice_number > 0:
             offset = slice_number - 1
             hosts = hosts[offset::slice_count]
 
diff --git a/awx/main/models/jobs.py b/awx/main/models/jobs.py
index 2203b7e31a..7e8ceaf192 100644
--- a/awx/main/models/jobs.py
+++ b/awx/main/models/jobs.py
@@ -332,9 +332,19 @@ class JobTemplate(UnifiedJobTemplate, JobOptions, SurveyJobTemplateMixin, Resour
         '''
         return self.create_unified_job(**kwargs)
 
+    def get_effective_slice_ct(self, kwargs):
+        actual_inventory = self.inventory
+        if self.ask_inventory_on_launch and 'inventory' in kwargs:
+            actual_inventory = kwargs['inventory']
+        if actual_inventory:
+            return min(self.job_slice_count, actual_inventory.hosts.count())
+        else:
+            return self.job_slice_count
+
     def create_unified_job(self, **kwargs):
         prevent_slicing = kwargs.pop('_prevent_slicing', False)
-        slice_event = bool(self.job_slice_count > 1 and (not prevent_slicing))
+        slice_ct = self.get_effective_slice_ct(kwargs)
+        slice_event = bool(slice_ct > 1 and (not prevent_slicing))
         if slice_event:
             # A Slice Job Template will generate a WorkflowJob rather than a Job
             from awx.main.models.workflow import WorkflowJobTemplate, WorkflowJobNode
@@ -347,13 +357,7 @@ class JobTemplate(UnifiedJobTemplate, JobOptions, SurveyJobTemplateMixin, Resour
             kwargs['_eager_fields'].setdefault('job_slice_count', 1)
         job = super(JobTemplate, self).create_unified_job(**kwargs)
         if slice_event:
-            try:
-                wj_config = job.launch_config
-            except JobLaunchConfig.DoesNotExist:
-                wj_config = JobLaunchConfig()
-            actual_inventory = wj_config.inventory if wj_config.inventory else self.inventory
-            for idx in range(min(self.job_slice_count,
-                                 actual_inventory.hosts.count())):
+            for idx in range(slice_ct):
                 create_kwargs = dict(workflow_job=job,
                                      unified_job_template=self,
                                      ancestor_artifacts=dict(job_slice=idx + 1))
diff --git a/awx/main/tests/functional/models/test_job.py b/awx/main/tests/functional/models/test_job.py
index 385daaf915..31b430d268 100644
--- a/awx/main/tests/functional/models/test_job.py
+++ b/awx/main/tests/functional/models/test_job.py
@@ -1,6 +1,6 @@
 import pytest
 
-from awx.main.models import JobTemplate, Job, JobHostSummary, WorkflowJob
+from awx.main.models import JobTemplate, Job, JobHostSummary, WorkflowJob, Inventory
 
 
 @pytest.mark.django_db
@@ -96,3 +96,13 @@ class TestSlicingModels:
             assert node.limit is None  # data not saved in node prompts
             job = node.job
             assert job.limit == 'foobar'
+
+    def test_effective_slice_count(self, job_template, inventory, organization):
+        job_template.inventory = inventory
+        assert job_template.inventory.hosts.count() == 0
+        job_template.job_slice_count = 2
+        job_template.inventory.hosts.create(name='foo1')
+        assert job_template.get_effective_slice_ct({})
+        inventory2 = Inventory.objects.create(organization=organization, name='fooinv')
+        [inventory2.hosts.create(name='foo{}'.format(i)) for i in range(3)]
+        assert job_template.get_effective_slice_ct({'inventory': inventory2})

From cca9de9a3ed0bfdda07f82f6bd0af8282fe42866 Mon Sep 17 00:00:00 2001
From: AlanCoding <arominge@redhat.com>
Date: Fri, 5 Apr 2019 15:28:18 -0400
Subject: [PATCH 2/2] set default slice ct for special cases

---
 awx/main/models/jobs.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/awx/main/models/jobs.py b/awx/main/models/jobs.py
index 7e8ceaf192..88b67a7d68 100644
--- a/awx/main/models/jobs.py
+++ b/awx/main/models/jobs.py
@@ -352,6 +352,10 @@ class JobTemplate(UnifiedJobTemplate, JobOptions, SurveyJobTemplateMixin, Resour
             kwargs['_parent_field_name'] = "job_template"
             kwargs.setdefault('_eager_fields', {})
             kwargs['_eager_fields']['is_sliced_job'] = True
+        elif self.job_slice_count > 1 and (not prevent_slicing):
+            # Unique case where JT was set to slice but hosts not available
+            kwargs.setdefault('_eager_fields', {})
+            kwargs['_eager_fields']['job_slice_count'] = 1
         elif prevent_slicing:
             kwargs.setdefault('_eager_fields', {})
             kwargs['_eager_fields'].setdefault('job_slice_count', 1)