EC2 - Return custom error response for DescribeRouteTable/DescribeVPC (#4225)

moto/ec2/exceptions.py

@@ -2,6 +2,21 @@ from __future__ import unicode_literals
 from moto.core.exceptions import RESTError
 
 
+# DescribeRouteTable has a custom root-tag - <Response> vs <ErrorResponse>
+# TF complains if the roottag is incorrect
+CUSTOM_ERROR_RESPONSE = """<?xml version="1.0" encoding="UTF-8"?>
+<Response>
+  <Errors>
+    <Error>
+      <Code>{{error_type}}</Code>
+      <Message>{{message}}</Message>
+    </Error>
+  </Errors>
+  <{{request_id_tag}}>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</{{request_id_tag}}>
+</Response>
+"""
+
+
 class EC2ClientError(RESTError):
     code = 400
     # EC2 uses <RequestID> as tag name in the XML response
@@ -60,8 +75,14 @@ class InvalidKeyPairFormatError(EC2ClientError):
 
 class InvalidVPCIdError(EC2ClientError):
     def __init__(self, vpc_id):
+        kwargs = {}
+        kwargs.setdefault("template", "custom_response")
+        self.templates["custom_response"] = CUSTOM_ERROR_RESPONSE
+
         super(InvalidVPCIdError, self).__init__(
-            "InvalidVpcID.NotFound", "VpcID {0} does not exist.".format(vpc_id)
+            "InvalidVpcID.NotFound",
+            "VpcID {0} does not exist.".format(vpc_id),
+            **kwargs
         )
 
 
@@ -176,9 +197,14 @@ class InvalidPermissionDuplicateError(EC2ClientError):
 
 class InvalidRouteTableIdError(EC2ClientError):
     def __init__(self, route_table_id):
+        kwargs = {}
+        kwargs.setdefault("template", "custom_response")
+        self.templates["custom_response"] = CUSTOM_ERROR_RESPONSE
+
         super(InvalidRouteTableIdError, self).__init__(
             "InvalidRouteTableID.NotFound",
             "The routeTable ID '{0}' does not exist".format(route_table_id),
+            **kwargs
         )
 
 

tests/test_ec2/test_server.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 import re
 import sure  # noqa
+import xmltodict
 
 import moto.server as server
 from tests import EXAMPLE_AMI_ID
@@ -24,3 +25,51 @@ def test_ec2_server_get():
 
     res = test_client.get("/?Action=DescribeInstances")
     res.data.decode("utf-8").should.contain(instance_id)
+
+
+def test_ec2_get_unknown_vpc():
+    """
+    Ensure that this call returns the error format in the right format
+    Terraform will throw errors when destroying a VPC otherwise
+    :return:
+    """
+    backend = server.create_backend_app("ec2")
+    test_client = backend.test_client()
+
+    res = test_client.get(
+        "/?Action=DescribeVpcs&VpcId.1=vpc-unknown",
+        headers={"Host": "ec2.us-east-1.amazonaws.com"},
+    )
+
+    res.status_code.should.equal(400)
+    body = xmltodict.parse(res.data.decode("utf-8"), dict_constructor=dict)
+    body.should.have.key("Response")
+    body["Response"].should.have.key("Errors")
+    body["Response"]["Errors"].should.have.key("Error")
+    error = body["Response"]["Errors"]["Error"]
+    error["Code"].should.equal("InvalidVpcID.NotFound")
+    error["Message"].should.equal("VpcID {'vpc-unknown'} does not exist.")
+
+
+def test_ec2_get_unknown_route_table():
+    """
+    Ensure that this call returns the error format in the right format
+    Terraform will throw errors when destroying a RouteTable otherwise
+    :return:
+    """
+    backend = server.create_backend_app("ec2")
+    test_client = backend.test_client()
+
+    res = test_client.get(
+        "/?Action=DescribeRouteTables&RouteTableId.1=rtb-unknown",
+        headers={"Host": "ec2.us-east-1.amazonaws.com"},
+    )
+
+    res.status_code.should.equal(400)
+    body = xmltodict.parse(res.data.decode("utf-8"), dict_constructor=dict)
+    body.should.have.key("Response")
+    body["Response"].should.have.key("Errors")
+    body["Response"]["Errors"].should.have.key("Error")
+    error = body["Response"]["Errors"]["Error"]
+    error["Code"].should.equal("InvalidRouteTableID.NotFound")
+    error["Message"].should.equal("The routeTable ID 'rtb-unknown' does not exist")