fix(validation): success threshold can only be equal to one when setting liveness probe. Error properly

Kubernetes has this restriction, catch it before it ever makes it that far.

Introducing jmespath now to later use in other places as well

Fixes #873

Author: helgi

rootfs/api/serializers.py

@@ -3,6 +3,7 @@
 """
 
 import json
+import jmespath
 import re
 import jsonschema
 import idna
@@ -337,6 +338,15 @@ def validate_healthcheck(self, data):
                 raise serializers.ValidationError(
                     "could not validate {}: {}".format(value, e.message))
 
+        # http://kubernetes.io/docs/api-reference/v1/definitions/#_v1_probe
+        # liveness only supports successThreshold=1, no other value
+        # This is not in the schema since readiness supports other values
+        threshold = jmespath.search('livenessProbe.successThreshold', data)
+        if threshold is not None and threshold != 1:
+            raise serializers.ValidationError(
+                'livenessProbe successThreshold can only be 1'
+            )
+
         return data
 
 

rootfs/api/tests/test_config.py

@@ -833,7 +833,9 @@ def test_config_healthchecks(self, mock_requests):
         self.assertIn('readinessProbe', resp.data['healthcheck'])
         self.assertEqual(resp.data['healthcheck'], readiness_probe['healthcheck'])
 
-        liveness_probe = {'healthcheck': {'livenessProbe': {'httpGet': {'port': 5000}}}}
+        liveness_probe = {'healthcheck': {'livenessProbe':
+                                          {'httpGet': {'port': 5000},
+                                           'successThreshold': 1}}}
         resp = self.client.post(
             '/v2/apps/{app_id}/config'.format(**locals()),
             liveness_probe)
@@ -879,6 +881,16 @@ def test_config_healthchecks_validations(self, mock_requests):
         )
         self.assertEqual(resp.status_code, 400, response.data)
 
+        # set liveness success threshold to a non-1 value
+        # Don't set one of the mandatory value
+        resp = self.client.post(
+            '/v2/apps/{app_id}/config'.format(**locals()),
+            {'healthcheck': {'livenessProbe':
+                             {'httpGet': {'path': '/', 'port': 5000},
+                              'successThreshold': 5}}}
+        )
+        self.assertEqual(resp.status_code, 400, response.data)
+
     def test_config_healthchecks_legacy(self, mock_requests):
         """
         Test that when a user uses `deis config:set HEALTHCHECK_URL=/`, the config

rootfs/requirements.txt

@@ -6,6 +6,7 @@ django-guardian==1.4.4
 djangorestframework==3.4.0
 docker-py==1.9.0
 gunicorn==19.6.0
+jmespath==0.9.0
 jsonfield==1.0.3
 morph==0.1.2
 ndg-httpsclient==0.4.2