Add new API backward compatibility support

trains/backend_api/session/datamodel.py

@@ -128,11 +128,14 @@ class NonStrictDataModelMixin(object):
     :summary: supplies an __init__ method that warns about unused keywords
     """
     def __init__(self, **kwargs):
-        unexpected = [key for key in kwargs if not key.startswith('_')]
-        if unexpected:
-            message = '{}: unused keyword argument(s) {}' \
-                .format(type(self).__name__, unexpected)
-            warnings.warn(message, UnusedKwargsWarning)
+        # unexpected = [key for key in kwargs if not key.startswith('_')]
+        # if unexpected:
+        #     message = '{}: unused keyword argument(s) {}' \
+        #         .format(type(self).__name__, unexpected)
+        #     warnings.warn(message, UnusedKwargsWarning)
+
+        # ignore extra data warnings
+        pass
 
 
 class NonStrictDataModel(DataModel, NonStrictDataModelMixin):

trains/backend_api/session/response.py

@@ -1,5 +1,6 @@
 import requests
 
+import six
 import jsonmodels.models
 import jsonmodels.fields
 import jsonmodels.errors
@@ -8,14 +9,21 @@ from .apimodel import ApiModel
 from .datamodel import NonStrictDataModelMixin
 
 
+class FloatOrStringField(jsonmodels.fields.BaseField):
+
+    """String field."""
+
+    types = (float, six.string_types,)
+
+
 class Response(ApiModel, NonStrictDataModelMixin):
     pass
 
 
 class _ResponseEndpoint(jsonmodels.models.Base):
     name = jsonmodels.fields.StringField()
-    requested_version = jsonmodels.fields.FloatField()
-    actual_version = jsonmodels.fields.FloatField()
+    requested_version = FloatOrStringField()
+    actual_version = FloatOrStringField()
 
 
 class ResponseMeta(jsonmodels.models.Base):
@@ -42,8 +50,8 @@ class ResponseMeta(jsonmodels.models.Base):
 
     def __str__(self):
         if self.result_code == requests.codes.ok:
-            return "<%d: %s/v%.1f>" % (self.result_code, self.endpoint.name, self.endpoint.actual_version)
+            return "<%d: %s/v%s>" % (self.result_code, self.endpoint.name, self.endpoint.actual_version)
         elif self._is_valid:
-            return "<%d/%d: %s/v%.1f (%s)>" % (self.result_code, self.result_subcode, self.endpoint.name,
-                                               self.endpoint.actual_version, self.result_msg)
+            return "<%d/%d: %s/v%s (%s)>" % (self.result_code, self.result_subcode, self.endpoint.name,
+                                             self.endpoint.actual_version, self.result_msg)
         return "<%d/%d: %s (%s)>" % (self.result_code, self.result_subcode, self.endpoint.name, self.result_msg)

trains/backend_api/session/session.py

@@ -5,6 +5,7 @@ from socket import gethostname
 
 import requests
 import six
+import jwt
 from pyhocon import ConfigTree
 from requests.auth import HTTPBasicAuth
 
@@ -34,6 +35,8 @@ class Session(TokenManager):
     _session_initial_timeout = (1.0, 10)
     _session_timeout = (5.0, None)
 
+    api_version = '2.1'
+
     # TODO: add requests.codes.gateway_timeout once we support async commits
     _retry_codes = [
         requests.codes.bad_gateway,
@@ -127,6 +130,13 @@ class Session(TokenManager):
 
         self.refresh_token()
 
+        # update api version from server response
+        try:
+            api_version = jwt.decode(self.token, verify=False).get('api_version', Session.api_version)
+            Session.api_version = str(api_version)
+        except (jwt.DecodeError, ValueError):
+            pass
+
     def _send_request(
         self,
         service,