Merge pull request #279 from DontShaveTheYak/develop

Release v0.7.0

Author: shadycuz

src/cf2tf/conversion/expressions.py

@@ -359,19 +359,68 @@ def get_att(template: "TemplateConverter", values: Any):
         values (Any): The values passed to the function.
 
     Raises:
-        TypeError: If values is not a list.
-        ValueError: If length of values is not 3.
-        TypeError: If the logicalNameOfResource and attributeName are not str.
-        KeyError: If the logicalNameOfResource is not found in the template.
+        TypeError: If values is not a String.
 
     Returns:
-        str: Terraform equivalent expression.
+        LiteralType: Terraform equivalent expression.
     """
 
-    if not isinstance(values, List):
-        raise TypeError(
-            f"Fn::GetAtt - The values must be a List, not {type(values).__name__}."
+    if isinstance(values, (str, StringType)):
+        return _get_att_string(template, values)
+
+    if isinstance(values, list):
+        return _get_att_list(template, values)
+
+    raise TypeError(
+        f"Fn::GetAtt - The value must be a String or List, not {type(values).__name__}."
+    )
+
+
+def _get_att_string(template: "TemplateConverter", values: Any):
+    """Converts AWS GetAtt intrinsic function to it's Terraform equivalent.
+
+    Args:
+        template (Configuration): The template being tested.
+        values (Any): The values passed to the function.
+
+    Raises:
+        ValueError: If the value doesn't contain a resource id and an attribute.
+
+    Returns:
+        LiteralType: Terraform equivalent expression.
+    """
+
+    if "." not in values:
+        raise ValueError(
+            "Fn::GetAtt - The value must contain a resource id and an attribute."
         )
+
+    parts = values.split(".")
+
+    resouce_id = parts[0]
+
+    attributes = ".".join(parts[1:])
+
+    result = _get_att_list(template, [resouce_id, attributes])
+
+    return result
+
+
+def _get_att_list(template: "TemplateConverter", values: Any):
+    """Converts AWS GetAtt intrinsic function to it's Terraform equivalent.
+
+    Args:
+        template (Configuration): The template being tested.
+        values (Any): The values passed to the function.
+
+    Raises:
+        ValueError: If the values length is not 2.
+        TypeError: If the values are not strings.
+
+    Returns:
+        LiteralType: Terraform equivalent expression.
+    """
+
     if not len(values) == 2:
         raise ValueError(
             (
@@ -712,7 +761,7 @@ def replace_var(m):
 
             attributes = ".".join(parts[1:])
 
-            result = get_att(template, [resouce_id, attributes])
+            result = _get_att_list(template, [resouce_id, attributes])
         else:
             result = ref(template, var)
 
@@ -775,7 +824,7 @@ def replace_var(m) -> str:
 
             attributes = ".".join(parts[1:])
 
-            result = get_att(template, [resouce_id, attributes])
+            result = _get_att_list(template, [resouce_id, attributes])
         else:
             result = ref(template, var)
 
@@ -982,6 +1031,7 @@ def wrap_in_curlys(input: str):
         **ALLOWED_NESTED_CONDITIONS,
         "Fn::Join": join,
         "Fn::Select": select,
+        "Fn::Sub": sub,
     },
     "Fn::If": {
         "Fn::Base64": base64,
@@ -993,6 +1043,7 @@ def wrap_in_curlys(input: str):
         "Fn::Select": select,
         "Fn::Sub": sub,
         "Ref": ref,
+        "Fn::Split": split,
     },
     "Fn::Not": ALLOWED_NESTED_CONDITIONS,
     "Fn::Or": ALLOWED_NESTED_CONDITIONS,
@@ -1001,6 +1052,7 @@ def wrap_in_curlys(input: str):
     "Fn::Cidr": {
         "Fn::Select": select,
         "Ref": ref,
+        "Fn::GetAtt": get_att,
     },
     "Fn::FindInMap": {
         "Fn::FindInMap": find_in_map,

src/cf2tf/convert.py

@@ -173,10 +173,7 @@ def resolve_values(  # noqa: max-complexity=13
                 # This takes care of keys that not intrinsic functions,
                 #  except for the condition func
                 if "Fn::" not in key and key != "Condition":
-                    data[key] = self.resolve_values(
-                        value,
-                        allowed_func,
-                    )
+                    data[key] = self.resolve_values(value, allowed_func, prev_func)
                     continue
 
                 # Takes care of the tricky 'Condition' key
@@ -194,23 +191,24 @@ def resolve_values(  # noqa: max-complexity=13
                         return functions.condition(self, value)
 
                     # Normal key like in an IAM role
-                    data[key] = self.resolve_values(
-                        value,
-                        allowed_func,
-                    )
+                    data[key] = self.resolve_values(value, allowed_func, prev_func)
                     continue
 
                 if key not in allowed_func:
                     raise ValueError(f"{key} not allowed to be nested in {prev_func}.")
 
+                prev_func = key
+
                 value = self.resolve_values(
-                    value, functions.ALLOWED_FUNCTIONS[key], key
+                    value, functions.ALLOWED_FUNCTIONS[key], prev_func
                 )
 
                 try:
                     return allowed_func[key](self, value)
-                except Exception:
-                    return CommentType(f"Unable to resolve {key} with value: {value}")
+                except Exception as e:
+                    return CommentType(
+                        f"Unable to resolve {key} with value: {value} because {e}"
+                    )
 
             return MapType(data)
         elif isinstance(data, list):

tests/test_conversion/test_expressions.py

@@ -298,11 +298,20 @@ def test_find_in_map(fake_tc: TemplateConverter):
 
 
 def test_get_att(fake_tc: TemplateConverter):
-    # Test that it will only take a list
+
     with pytest.raises(TypeError) as type_error:
         expressions.get_att(fake_tc, {})
 
-    assert "Fn::GetAtt - The values must be a List, not dict." in str(type_error)
+    assert "Fn::GetAtt - The value must be a String or List, not dict." in str(
+        type_error
+    )
+    # Test that string must be in the correct format
+    with pytest.raises(ValueError) as value_error:
+        expressions.get_att(fake_tc, "foo")
+
+    assert "Fn::GetAtt - The value must contain a resource id and an attribute." in str(
+        value_error
+    )
 
     # Test that list size must be two
     with pytest.raises(ValueError) as value_error:
@@ -343,6 +352,10 @@ def test_get_att(fake_tc: TemplateConverter):
 
     assert result == expected_result
 
+    result = expressions.get_att(fake_tc, f"{resource_id}.{test_attr}")
+
+    assert result == expected_result
+
 
 def test_get_att_nested(fake_tc: TemplateConverter):
     """Test that nested cloudformation attributes work."""
@@ -394,7 +407,7 @@ def test_get_att_nested(fake_tc: TemplateConverter):
 
     expected_result = f"aws_cloudformation_stack.{resource_id}.{test_attr.lower()}"
 
-    result = expressions.get_att(fake_tc, [resource_id, test_attr])
+    result = expressions.get_att(fake_tc, f"{resource_id}.{test_attr}")
 
     assert result == expected_result