[VVP] Flag duplicate parameters in .env files

Also some minor tweaks to preload generation so it doesn't fail on
partial heat templates

Change-Id: If39288dde645b0b53a338e7672336807ffa1b6d7
Issue-ID: VVP-284
Signed-off-by: Lovett, Trevor <trevor.lovett@att.com>

2 files changed, 35 insertions, 14 deletions

diff --git a/ice_validator/tests/utils/vm_types.py b/ice_validator/tests/utils/vm_types.py
index e0ea7e7..12fc5a2 100644
--- a/ice_validator/tests/utils/vm_types.py
+++ b/ice_validator/tests/utils/vm_types.py
@@ -99,7 +99,7 @@ def get_vm_type_for_nova_server(resource):
     vm_types = get_vm_types_for_resource(resource)
 
     # if more than one vm_type was identified, return None
-    if len(vm_types) > 1:
+    if not vm_types or len(vm_types) > 1:
         return None
 
     return vm_types.pop()
diff --git a/ice_validator/tests/utils/yaml_custom_utils.py b/ice_validator/tests/utils/yaml_custom_utils.py
index 6b99dea..597352a 100644
--- a/ice_validator/tests/utils/yaml_custom_utils.py
+++ b/ice_validator/tests/utils/yaml_custom_utils.py
@@ -38,22 +38,43 @@
 #
 
 from yaml.constructor import ConstructorError
+from yaml.nodes import MappingNode
 
+try:
+    from yaml import CLoader as SafeLoader
+except ImportError:
+    from yaml import SafeLoader
 
-def raise_duplicates_keys(loader, node, deep=False):
-    """Raise error when duplicate keys found in yaml file."""
 
-    mapping = {}
-    for key_node, value_node in node.value:
-        key = loader.construct_object(key_node, deep=deep)
-        value = loader.construct_object(value_node, deep=deep)
-        if key in mapping:
+class UniqueKeyLoader(SafeLoader):
+    def construct_mapping(self, node, deep=False):
+        if not isinstance(node, MappingNode):
             raise ConstructorError(
-                "while constructing a mapping",
+                None,
+                None,
+                "expected a mapping node, but found %s" % node.id,
                 node.start_mark,
-                "found duplicate key (%s)" % key,
-                key_node.start_mark,
             )
-        mapping[key] = value
-
-    return loader.construct_mapping(node, deep)
+        mapping = {}
+        for key_node, value_node in node.value:
+            key = self.construct_object(key_node, deep=deep)
+            try:
+                hash(key)
+            except TypeError as exc:
+                raise ConstructorError(
+                    "while constructing a mapping",
+                    node.start_mark,
+                    "found unacceptable key (%s)" % exc,
+                    key_node.start_mark,
+                )
+            # check for duplicate keys
+            if key in mapping:
+                raise ConstructorError(
+                    "while constructing a mapping",
+                    node.start_mark,
+                    "found duplicate key",
+                    key_node.start_mark,
+                )
+            value = self.construct_object(value_node, deep=deep)
+            mapping[key] = value
+        return mapping