Merge pull request #4 from zdc/T2117

Cloud-init: T2117: Updated to 20.1 version

1 files changed, 22 insertions, 0 deletions

diff --git a/cloudinit/safeyaml.py b/cloudinit/safeyaml.py
index 7bcf9dd3..d6f5f95b 100644
--- a/cloudinit/safeyaml.py
+++ b/cloudinit/safeyaml.py
@@ -6,6 +6,8 @@
 
 import yaml
 
+YAMLError = yaml.YAMLError
+
 
 class _CustomSafeLoader(yaml.SafeLoader):
     def construct_python_unicode(self, node):
@@ -17,7 +19,27 @@ _CustomSafeLoader.add_constructor(
     _CustomSafeLoader.construct_python_unicode)
 
 
+class NoAliasSafeDumper(yaml.dumper.SafeDumper):
+    """A class which avoids constructing anchors/aliases on yaml dump"""
+
+    def ignore_aliases(self, data):
+        return True
+
+
 def load(blob):
     return(yaml.load(blob, Loader=_CustomSafeLoader))
 
+
+def dumps(obj, explicit_start=True, explicit_end=True, noalias=False):
+    """Return data in nicely formatted yaml."""
+
+    return yaml.dump(obj,
+                     line_break="\n",
+                     indent=4,
+                     explicit_start=explicit_start,
+                     explicit_end=explicit_end,
+                     default_flow_style=False,
+                     Dumper=(NoAliasSafeDumper
+                             if noalias else yaml.dumper.Dumper))
+
 # vi: ts=4 expandtab