Fixing typing issues in config parser

registrar/config.py

@@ -16,7 +16,7 @@ import yaml
 ENV_PATTERN = re.compile(r".*?\${(\w+)}.*?")
 
 
-def constructor_env_variables(loader: yaml.Loader, node: str):
+def constructor_env_variables(loader: yaml.Loader, node):
     """Extracts the environment variable from the node's value
 
     Args:
@@ -28,18 +28,19 @@ def constructor_env_variables(loader: yaml.Loader, node: str):
         variable
     """
     value = loader.construct_scalar(node)
-    match = ENV_PATTERN.findall(value)  # to find all env variables in line
-    if match:
-        full_value = value
-        for g in match:
-            env_variable = os.environ.get(
-                g,
-            )
-            if env_variable is not None:
-                full_value = full_value.replace(f"${{{g}}}", env_variable)
-            else:
-                return None
-        return full_value
+    if isinstance(value, str):
+        match = ENV_PATTERN.findall(value)  # to find all env variables in line
+        if match:
+            full_value = value
+            for g in match:
+                env_variable = os.environ.get(
+                    g,
+                )
+                if env_variable is not None:
+                    full_value = full_value.replace(f"${{{g}}}", env_variable)
+                else:
+                    return None
+            return full_value
     return value