powerful configuration management

1 files changed, 31 insertions, 0 deletions

diff --git a/kvmd/yamlconf/loader.py b/kvmd/yamlconf/loader.py
new file mode 100644
index 00000000..cd7ae4fd
--- /dev/null
+++ b/kvmd/yamlconf/loader.py
@@ -0,0 +1,31 @@
+import os
+
+from typing import IO
+from typing import Any
+
+import yaml
+import yaml.loader
+import yaml.nodes
+
+
+# =====
+def load_yaml_file(path: str) -> Any:
+    with open(path) as yaml_file:
+        try:
+            return yaml.load(yaml_file, _YamlLoader)
+        except Exception:
+            # Reraise internal exception as standard ValueError and show the incorrect file
+            raise ValueError("Incorrect YAML syntax in file '{}'".format(path))
+
+
+class _YamlLoader(yaml.loader.Loader):  # pylint: disable=too-many-ancestors
+    def __init__(self, yaml_file: IO) -> None:
+        yaml.loader.Loader.__init__(self, yaml_file)
+        self.__root = os.path.dirname(yaml_file.name)
+
+    def include(self, node: yaml.nodes.Node) -> str:
+        path = os.path.join(self.__root, self.construct_scalar(node))  # pylint: disable=no-member
+        return load_yaml_file(path)
+
+
+_YamlLoader.add_constructor("!include", _YamlLoader.include)  # pylint: disable=no-member