Support numbers, boolean when doing a Sub parameter value (#1774)

aws-cloudformation · Nov 12, 2020 · a735424 · a735424
1 parent 34f34e4
commit a735424
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Showing 4 changed files with 16 additions and 4 deletions.
diff --git a/src/cfnlint/rules/functions/Sub.py b/src/cfnlint/rules/functions/Sub.py
@@ -85,8 +85,8 @@ def _test_parameters(self, parameters, cfn, tree):
                     message = 'Sub parameter should be an object of 1 for {0}'
                     matches.append(RuleMatch(
                         param_tree, message.format('/'.join(map(str, tree)))))
-            elif not isinstance(parameter_value_obj, six.string_types):
-                message = 'Sub parameter should be an object of 1 or string for {0}'
+            elif isinstance(parameter_value_obj, list):
+                message = 'Sub parameter value should be a string for {0}'
                 matches.append(RuleMatch(
                     param_tree, message.format('/'.join(map(str, tree)))))
 

diff --git a/test/fixtures/templates/bad/functions/sub.yaml b/test/fixtures/templates/bad/functions/sub.yaml
@@ -54,8 +54,10 @@ Resources:
     Properties:
       CidrBlock:
         Fn::Sub:
-        - "${myCidr}"
+        - "${myCidr}${number}"
         - myCidr: !Ref CidrBlock
+          number:
+          - bad
   LaunchConfiguration:
     Type: AWS::AutoScaling::LaunchConfiguration
     Properties:

diff --git a/test/fixtures/templates/good/functions/sub.yaml b/test/fixtures/templates/good/functions/sub.yaml
@@ -13,6 +13,8 @@ Parameters:
     Description: App Package
   mySubnets:
     Type: List<AWS::EC2::Subnet::Id>
+  CidrBlock:
+    Type: String
 Resources:
   myInstance:
     Type: AWS::EC2::Instance
@@ -64,6 +66,14 @@ Resources:
     Properties:
       ProductName: example
       ProvisioningArtifactName: v1
+  myVPc2:
+    Type: AWS::EC2::VPC
+    Properties:
+      CidrBlock:
+        Fn::Sub:
+        - "${myCidr}${number}"
+        - myCidr: !Ref CidrBlock
+          number: 1
 Outputs:
   OutputSub:
     Value: !Sub '${ProvisionedProduct.Outputs.Example}-example'
diff --git a/test/unit/rules/functions/test_sub.py b/test/unit/rules/functions/test_sub.py
@@ -23,4 +23,4 @@ def test_file_positive(self):
 
     def test_file_negative(self):
         """Test failure"""
-        self.helper_file_negative('test/fixtures/templates/bad/functions/sub.yaml', 15)
+        self.helper_file_negative('test/fixtures/templates/bad/functions/sub.yaml', 16)