Implementation of #625

python/seldon_core/wrapper.py

@@ -19,6 +19,10 @@ def get_rest_microservice(user_model):
     app = Flask(__name__, static_url_path='')
     CORS(app)
 
+    if hasattr(user_model, 'model_error_handler'):
+        logger.info('Registering the custom error handler...')
+        app.register_blueprint(user_model.model_error_handler)
+
     @app.errorhandler(SeldonMicroserviceException)
     def handle_invalid_usage(error):
         response = jsonify(error.to_dict())

python/tests/test_application_exception_microservice.py

@@ -0,0 +1,93 @@
+import json
+import numpy as np
+from google.protobuf import json_format
+import base64
+import tensorflow as tf
+from tensorflow.core.framework.tensor_pb2 import TensorProto
+
+from seldon_core.wrapper import get_rest_microservice, SeldonModelGRPC, get_grpc_server
+from seldon_core.proto import prediction_pb2
+from seldon_core.user_model import SeldonComponent
+
+import flask
+from flask import jsonify
+
+class UserCustomException(Exception):
+    status_code = 404
+
+    def __init__(self, message, application_error_code,http_status_code):
+        Exception.__init__(self)
+        self.message = message
+        if http_status_code is not None:
+            self.status_code = http_status_code
+        self.application_error_code = application_error_code
+
+    def to_dict(self):
+        rv = {"status": {"status": self.status_code, "message": self.message,
+                         "app_code": self.application_error_code}}
+        return rv
+
+class UserObject(SeldonComponent):
+
+    model_error_handler = flask.Blueprint('error_handlers', __name__)
+
+    @model_error_handler.app_errorhandler(UserCustomException)
+    def handleCustomError(error):
+        response = jsonify(error.to_dict())
+        response.status_code = error.status_code
+        return response
+
+
+    def __init__(self, metrics_ok=True, ret_nparray=False, ret_meta=False):
+        self.metrics_ok = metrics_ok
+        self.ret_nparray = ret_nparray
+        self.nparray = np.array([1, 2, 3])
+        self.ret_meta = ret_meta
+
+    def predict(self, X, features_names, **kwargs):
+        raise UserCustomException('Test-Error-Msg',1402,402)
+        return X
+
+
+class UserObjectLowLevel(SeldonComponent):
+
+    model_error_handler = flask.Blueprint('error_handlers', __name__)
+
+    @model_error_handler.app_errorhandler(UserCustomException)
+    def handleCustomError(error):
+        response = jsonify(error.to_dict())
+        response.status_code = error.status_code
+        return response
+
+
+    def __init__(self, metrics_ok=True, ret_nparray=False):
+        self.metrics_ok = metrics_ok
+        self.ret_nparray = ret_nparray
+        self.nparray = np.array([1, 2, 3])
+
+    def predict_rest(self, request):
+        raise UserCustomException('Test-Error-Msg',1402,402)
+        return {"data": {"ndarray": [9, 9]}}
+
+
+def test_raise_exception():
+    user_object = UserObject()
+    app = get_rest_microservice(user_object)
+    client = app.test_client()
+    rv = client.get('/predict?json={"data":{"names":["a","b"],"ndarray":[[1,2]]}}')
+    j = json.loads(rv.data)
+    print(j)
+    assert rv.status_code == 402
+    assert j["status"]["app_code"] == 1402
+
+
+def test_raise_eception_lowlevel():
+    user_object = UserObjectLowLevel()
+    app = get_rest_microservice(user_object)
+    client = app.test_client()
+    rv = client.get('/predict?json={"data":{"ndarray":[1,2]}}')
+    j = json.loads(rv.data)
+    print(j)
+    assert rv.status_code == 402
+    assert j["status"]["app_code"] == 1402
+