[enh] new utils to read yaml files

doc/utils/filesystem.rst

@@ -3,6 +3,7 @@ File system operation utils
 
 .. autofunction:: moulinette.utils.filesystem.read_file
 .. autofunction:: moulinette.utils.filesystem.read_json
+.. autofunction:: moulinette.utils.filesystem.read_yaml
 .. autofunction:: moulinette.utils.filesystem.write_to_file
 .. autofunction:: moulinette.utils.filesystem.append_to_file
 .. autofunction:: moulinette.utils.filesystem.write_to_json

locales/en.json

@@ -41,6 +41,7 @@
     "cannot_write_file": "Could not write file {file:s} (reason: {error:s})",
     "unknown_error_reading_file": "Unknown error while trying to read file {file:s}",
     "corrupted_json": "Corrupted json read from {ressource:s} (reason: {error:s})",
+    "corrupted_yaml": "Corrupted yaml read from {ressource:s} (reason: {error:s})",
     "error_writing_file":  "Error when writing file {file:s}: {error:s}",
     "error_removing": "Error when removing {path:s}: {error:s}",
     "error_changing_file_permissions": "Error when changing permissions for {path:s}: {error:s}",

moulinette/utils/filesystem.py

@@ -1,4 +1,5 @@
 import os
+import yaml
 import errno
 import shutil
 import json
@@ -64,6 +65,28 @@ def read_json(file_path):
     return loaded_json
 
 
+def read_yaml(file_path):
+    """
+    Safely read a yaml file
+
+    Keyword argument:
+        file_path -- Path to the yaml file
+    """
+
+    # Read file
+    file_content = read_file(file_path)
+
+    # Try to load yaml to check if it's syntaxically correct
+    try:
+        loaded_yaml = yaml.safe_load(file_content)
+    except ValueError as e:
+        raise MoulinetteError(errno.EINVAL,
+                              m18n.g('corrupted_yaml',
+                                     ressource=file_path, error=str(e)))
+
+    return loaded_yaml
+
+
 def write_to_file(file_path, data, file_mode="w"):
     """
     Write a single string or a list of string to a text file.