Return 400 Bad Request for extra capability keys longer than 64 chars

Length of extra capability keys is limited to 64 characters in the DB
schema. However, the host create API can create a host based on a
request that has a longer extra capability key, only to return a 500
Internal Server Error.

With this patch, the API checks the key length before creating a host
and returns a 400 Bad Request status code if it is too long.

Change-Id: I2cf4ede787e0f65385376832ce410d694df094ff
Closes-Bug: #1709639

blazar/manager/exceptions.py

@@ -153,6 +153,11 @@ class MissingParameter(exceptions.BlazarException):
     msg_fmt = _("Missing parameter %(param)s")
 
 
+class ExtraCapabilityTooLong(exceptions.BlazarException):
+    code = 400
+    msg_fmt = _("Extra capability key too long")
+
+
 class InvalidState(exceptions.BlazarException):
     code = 409
     msg_fmt = _("Invalid State %(state)s for %(id)s")

blazar/plugins/oshosts/host_plugin.py

@@ -341,6 +341,10 @@ class PhysicalHostPlugin(base.BasePlugin, nova.NovaClientWrapper):
             extra_capabilities = dict(
                 (key, host_values[key]) for key in extra_capabilities_keys
             )
+
+            if any([len(key) > 64 for key in extra_capabilities_keys]):
+                raise manager_ex.ExtraCapabilityTooLong()
+
             pool = nova.ReservationPool()
             pool.add_computehost(self.freepool_name,
                                  host_details['service_name'])

blazar/tests/plugins/test_physical_host_plugin.py

@@ -221,6 +221,19 @@ class PhysicalHostPluginTestCase(tests.TestCase):
         self.db_host_extra_capability_create.assert_called_once_with(fake_capa)
         self.assertEqual(host, fake_host)
 
+    def test_create_host_with_capabilities_too_long(self):
+        fake_host = self.fake_host.copy()
+        fake_host.update({'foo': 'bar'})
+        # NOTE(sbauza): 'id' will be pop'd, we need to keep track of it
+        fake_request = fake_host.copy()
+        long_key = ""
+        for i in range(65):
+            long_key += "0"
+        fake_request[long_key] = "foo"
+        self.assertRaises(manager_exceptions.ExtraCapabilityTooLong,
+                          self.fake_phys_plugin.create_computehost,
+                          fake_request)
+
     def test_create_host_without_trust_id(self):
         self.assertRaises(manager_exceptions.MissingTrustId,
                           self.fake_phys_plugin.create_computehost, {})