[PATCH net-next v2 10/14] tools: ynl: load jsonschema on demand

[Jakub Kicinski <kuba@xxxxxxxxxx>]

The CLI script tries to validate jsonschema by default.
It's seems better to validate too many times than too few.
However, when copying the scripts to random servers having
to install jsonschema is tedious. Load jsonschema via
importlib, and let the user opt out.

Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
---
 tools/net/ynl/cli.py        |  4 ++++
 tools/net/ynl/lib/nlspec.py | 11 ++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/tools/net/ynl/cli.py b/tools/net/ynl/cli.py
index 05d1f4069ce1..e64f1478764f 100755
--- a/tools/net/ynl/cli.py
+++ b/tools/net/ynl/cli.py
@@ -13,6 +13,7 @@ from lib import YnlFamily
     parser = argparse.ArgumentParser(description='YNL CLI sample')
     parser.add_argument('--spec', dest='spec', type=str, required=True)
     parser.add_argument('--schema', dest='schema', type=str)
+    parser.add_argument('--no-schema', action='store_true')
     parser.add_argument('--json', dest='json_text', type=str)
     parser.add_argument('--do', dest='do', type=str)
     parser.add_argument('--dump', dest='dump', type=str)
@@ -20,6 +21,9 @@ from lib import YnlFamily
     parser.add_argument('--subscribe', dest='ntf', type=str)
     args = parser.parse_args()
 
+    if args.no_schema:
+        args.schema = ''
+
     attrs = {}
     if args.json_text:
         attrs = json.loads(args.json_text)
diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
index 4aa3b1ad97f0..e204679ad8b7 100644
--- a/tools/net/ynl/lib/nlspec.py
+++ b/tools/net/ynl/lib/nlspec.py
@@ -1,12 +1,16 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 import collections
-import jsonschema
+import importlib
 import os
 import traceback
 import yaml
 
 
+# To be loaded dynamically as needed
+jsonschema = None
+
+
 class SpecElement:
     """Netlink spec element.
 
@@ -197,9 +201,14 @@ import yaml
         if schema_path is None:
             schema_path = os.path.dirname(os.path.dirname(spec_path)) + f'/{self.proto}.yaml'
         if schema_path:
+            global jsonschema
+
             with open(schema_path, "r") as stream:
                 schema = yaml.safe_load(stream)
 
+            if jsonschema is None:
+                jsonschema = importlib.import_module("jsonschema")
+
             jsonschema.validate(self.yaml, schema)
 
         self.attr_sets = collections.OrderedDict()
-- 
2.39.1