From 16812542f88ac2a14057d4e258e22103e847deab Mon Sep 17 00:00:00 2001
From: Ryan Petrello <rpetrell@redhat.com>
Date: Thu, 17 Oct 2019 16:51:30 -0400
Subject: [PATCH] implement a simple periodic pod reaper for container groups

see: https://github.com/ansible/awx/issues/4911
---
 awx/main/scheduler/kubernetes.py | 28 +++++++++++++++++++++++++++-
 awx/main/tasks.py                | 19 +++++++++++++++++++
 awx/settings/defaults.py         |  5 +++++
 3 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/awx/main/scheduler/kubernetes.py b/awx/main/scheduler/kubernetes.py
index 90f2849c3d..00f82a3859 100644
--- a/awx/main/scheduler/kubernetes.py
+++ b/awx/main/scheduler/kubernetes.py
@@ -1,3 +1,4 @@
+import collections
 import os
 import stat
 import time
@@ -47,6 +48,27 @@ class PodManager(object):
         else:
             logger.warn(f"Pod {self.pod_name} did not start. Status is {pod.status.phase}.")
 
+    @classmethod
+    def list_active_jobs(self, instance_group):
+        task = collections.namedtuple('Task', 'id instance_group')(
+            id='',
+            instance_group=instance_group
+        )
+        pm = PodManager(task)
+        try:
+            for pod in pm.kube_api.list_namespaced_pod(
+                pm.namespace,
+                label_selector='ansible-awx={}'.format(settings.INSTALL_UUID)
+            ).to_dict().get('items', []):
+                job = pod['metadata'].get('labels', {}).get('ansible-awx-job-id')
+                if job:
+                    try:
+                        yield int(job)
+                    except ValueError:
+                        pass
+        except Exception:
+            logger.exception('Failed to list pods for container group {}'.format(instance_group))
+
     def delete(self):
         return self.kube_api.delete_namespaced_pod(name=self.pod_name,
                                                    namespace=self.namespace,
@@ -71,7 +93,7 @@ class PodManager(object):
 
     @property
     def pod_name(self):
-        return f"job-{self.task.id}"
+        return f"awx-job-{self.task.id}"
 
     @property
     def pod_definition(self):
@@ -102,6 +124,10 @@ class PodManager(object):
 
         if self.task:
             pod_spec['metadata']['name'] = self.pod_name
+            pod_spec['metadata']['labels'] = {
+                'ansible-awx': settings.INSTALL_UUID,
+                'ansible-awx-job-id': str(self.task.id)
+            }
             pod_spec['spec']['containers'][0]['name'] = self.pod_name
 
         return pod_spec
diff --git a/awx/main/tasks.py b/awx/main/tasks.py
index 10aac79dd9..ff53cd00ac 100644
--- a/awx/main/tasks.py
+++ b/awx/main/tasks.py
@@ -458,6 +458,25 @@ def cluster_node_heartbeat():
                 logger.exception('Error marking {} as lost'.format(other_inst.hostname))
 
 
+@task(queue=get_local_queuename)
+def awx_k8s_reaper():
+    from awx.main.scheduler.kubernetes import PodManager # prevent circular import
+    for group in InstanceGroup.objects.filter(credential__isnull=False).iterator():
+        if group.is_containerized:
+            logger.debug("Checking for orphaned k8s pods for {}.".format(group))
+            for job in UnifiedJob.objects.filter(
+                pk__in=list(PodManager.list_active_jobs(group))
+            ).exclude(status__in=ACTIVE_STATES):
+                logger.debug('{} is no longer active, reaping orphaned k8s pod'.format(job.log_format))
+                try:
+                    PodManager(job).delete()
+                except Exception:
+                    logger.exception("Failed to delete orphaned pod {} from {}".format(
+                        job.log_format, group
+                    ))
+
+
+
 @task(queue=get_local_queuename)
 def awx_isolated_heartbeat():
     local_hostname = settings.CLUSTER_HOST_ID
diff --git a/awx/settings/defaults.py b/awx/settings/defaults.py
index 07c76f8b01..658d41d6b3 100644
--- a/awx/settings/defaults.py
+++ b/awx/settings/defaults.py
@@ -479,6 +479,11 @@ CELERYBEAT_SCHEDULE = {
         'schedule': timedelta(seconds=20),
         'options': {'expires': 20}
     },
+    'k8s_reaper': {
+        'task': 'awx.main.tasks.awx_k8s_reaper',
+        'schedule': timedelta(seconds=60),
+        'options': {'expires': 50,}
+    },
     # 'isolated_heartbeat': set up at the end of production.py and development.py
 }
 AWX_INCONSISTENT_TASK_INTERVAL = 60 * 3