Add Fn::ImportValue support

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -5,7 +5,7 @@ import boto
 import boto.s3
 import boto.s3.key
 from botocore.exceptions import ClientError
-from moto import mock_cloudformation, mock_s3
+from moto import mock_cloudformation, mock_s3, mock_sqs
 
 import json
 import sure  # noqa
@@ -80,9 +80,23 @@ dummy_output_template = {
     }
 }
 
+dummy_import_template = {
+    "AWSTemplateFormatVersion": "2010-09-09",
+    "Resources": {
+        "Queue": {
+            "Type": "AWS::SQS::Queue",
+            "Properties": {
+                "QueueName": {"Fn::ImportValue": 'My VPC ID'},
+                "VisibilityTimeout": 60,
+            }
+        }
+    }
+}
+
 dummy_template_json = json.dumps(dummy_template)
 dummy_update_template_json = json.dumps(dummy_template)
 dummy_output_template_json = json.dumps(dummy_output_template)
+dummy_import_template_json = json.dumps(dummy_import_template)
 
 
 @mock_cloudformation
@@ -501,3 +515,23 @@ def test_export_names_must_be_unique():
             StackName="test_stack",
             TemplateBody=dummy_output_template_json,
         )
+
+@mock_sqs
+@mock_cloudformation
+def test_stack_with_imports():
+    cf = boto3.resource('cloudformation', region_name='us-east-1')
+    ec2_resource = boto3.resource('sqs', region_name='us-east-1')
+
+    output_stack = cf.create_stack(
+        StackName="test_stack1",
+        TemplateBody=dummy_output_template_json,
+    )
+    import_stack = cf.create_stack(
+        StackName="test_stack2",
+        TemplateBody=dummy_import_template_json
+    )
+
+    output_stack.outputs.should.have.length_of(1)
+    output = output_stack.outputs[0]['OutputValue']
+    queue = ec2_resource.get_queue_by_name(QueueName=output)
+    queue.should_not.be.none

tests/test_cloudformation/test_stack_parsing.py

@@ -7,7 +7,7 @@ import sure  # noqa
 
 from moto.cloudformation.exceptions import ValidationError
 from moto.cloudformation.models import FakeStack
-from moto.cloudformation.parsing import resource_class_from_type, parse_condition
+from moto.cloudformation.parsing import resource_class_from_type, parse_condition, Export
 from moto.sqs.models import Queue
 from moto.s3.models import FakeBucket
 from boto.cloudformation.stack import Output
@@ -105,6 +105,38 @@ sub_template = {
     }
 }
 
+export_value_template = {
+    "AWSTemplateFormatVersion": "2010-09-09",
+    "Resources": {
+        "Queue": {
+            "Type": "AWS::SQS::Queue",
+            "Properties": {
+                "QueueName": {"Fn::Sub": '${AWS::StackName}-queue'},
+                "VisibilityTimeout": 60,
+            }
+        }
+    },
+    "Outputs": {
+        "Output1": {
+            "Value": "value",
+            "Export": {"Name": 'queue-us-west-1'}
+        }
+    }
+}
+
+import_value_template = {
+    "AWSTemplateFormatVersion": "2010-09-09",
+    "Resources": {
+        "Queue": {
+            "Type": "AWS::SQS::Queue",
+            "Properties": {
+                "QueueName": {"Fn::ImportValue": 'queue-us-west-1'},
+                "VisibilityTimeout": 60,
+            }
+        }
+    }
+}
+
 outputs_template = dict(list(dummy_template.items()) +
                         list(output_dict.items()))
 bad_outputs_template = dict(
@@ -120,6 +152,8 @@ get_attribute_outputs_template_json = json.dumps(
     get_attribute_outputs_template)
 split_select_template_json = json.dumps(split_select_template)
 sub_template_json = json.dumps(sub_template)
+export_value_template_json = json.dumps(export_value_template)
+import_value_template_json = json.dumps(import_value_template)
 
 
 def test_parse_stack_resources():
@@ -327,3 +361,22 @@ def test_sub():
     queue1 = stack.resource_map['Queue1']
     queue2 = stack.resource_map['Queue2']
     queue2.name.should.equal(queue1.name)
+
+
+def test_import():
+    export_stack = FakeStack(
+        stack_id="test_id",
+        name="test_stack",
+        template=export_value_template_json,
+        parameters={},
+        region_name='us-west-1')
+    import_stack = FakeStack(
+        stack_id="test_id",
+        name="test_stack",
+        template=import_value_template_json,
+        parameters={},
+        region_name='us-west-1',
+        cross_stack_resources={export_stack.exports[0].value: export_stack.exports[0]})
+
+    queue = import_stack.resource_map['Queue']
+    queue.name.should.equal("value")