The schema validation part was not working. I got it going with the
following changes. It then flags some problems in ethtool.yaml.

diff --git a/tools/net/ynl/samples/ethtool.py b/tools/net/ynl/samples/ethtool.py
index 63c8e29f8e5d..4c5a4629748d 100755
--- a/tools/net/ynl/samples/ethtool.py
+++ b/tools/net/ynl/samples/ethtool.py

@@ -14,7 +14,7 @@ def main():
     parser.add_argument('--ifindex', dest='ifindex', type=str)
     args = parser.parse_args()
 
-    ynl = YnlFamily(args.spec)
+    ynl = YnlFamily(args.spec, args.schema)
 
     if args.dev_name:
         channels = ynl.channels_get({'header': {'dev_name': args.dev_name}})

diff --git a/tools/net/ynl/samples/ynl.py b/tools/net/ynl/samples/ynl.py
index 59c178e063f1..35c894b0ec19 100644
--- a/tools/net/ynl/samples/ynl.py
+++ b/tools/net/ynl/samples/ynl.py

@@ -247,7 +247,7 @@ class YnlFamily:
             self.yaml = yaml.safe_load(stream)
 
         if schema:
-            with open(os.path.dirname(os.path.dirname(file_name)) + '/schema.yaml', "r") as stream:
+            with open(schema, "r") as stream:
                 schema = yaml.safe_load(stream)
 
             jsonschema.validate(self.yaml, schema)