Allow manually running a health check, and make other adjustments to the health check trigger (#11002)

* Full finalize the planned work for health checks of execution nodes

* Implementation of instance health_check endpoint

* Also do version conditional to node_type

* Do not use receptor mesh to check main cluster nodes health

* Fix bugs from testing health check of cluster nodes, add doc

* Add a few fields to health check serializer missed before

* Light refactoring of error field processing

* Fix errors clearing error, write more unit tests

* Update health check info in docs

* Bump migration of health check after rebase

* Mark string for translation

* Add related health_check link for system auditors too

* Handle health_check cluster node timeout, add errors for peer judgement

awx/api/serializers.py

@@ -4786,6 +4786,9 @@ class InstanceSerializer(BaseSerializer):
             "hostname",
             "created",
             "modified",
+            "last_seen",
+            "last_health_check",
+            "errors",
             'capacity_adjustment',
             "version",
             "capacity",
@@ -4806,6 +4809,8 @@ class InstanceSerializer(BaseSerializer):
         res = super(InstanceSerializer, self).get_related(obj)
         res['jobs'] = self.reverse('api:instance_unified_jobs_list', kwargs={'pk': obj.pk})
         res['instance_groups'] = self.reverse('api:instance_instance_groups_list', kwargs={'pk': obj.pk})
+        if self.context['request'].user.is_superuser or self.context['request'].user.is_system_auditor:
+            res['health_check'] = self.reverse('api:instance_health_check', kwargs={'pk': obj.pk})
         return res
 
     def get_consumed_capacity(self, obj):
@@ -4818,6 +4823,13 @@ class InstanceSerializer(BaseSerializer):
             return float("{0:.2f}".format(((float(obj.capacity) - float(obj.consumed_capacity)) / (float(obj.capacity))) * 100))
 
 
+class InstanceHealthCheckSerializer(BaseSerializer):
+    class Meta:
+        model = Instance
+        read_only_fields = ('uuid', 'hostname', 'version', 'last_health_check', 'errors', 'cpu', 'memory', 'cpu_capacity', 'mem_capacity', 'capacity')
+        fields = read_only_fields
+
+
 class InstanceGroupSerializer(BaseSerializer):
 
     show_capabilities = ['edit', 'delete']