Convert IPv6 addresses to lowercase in apply-patch (#2299)

Fixes sonic-net/sonic-buildimage#11622

- What I did
Convert IPv6 addresses to lowercase in apply-patch for remove op

- How I did it
python regex on 'remove' op in JSON patch input file

- How to verify it
Manual test of created bug, Unit test

config/main.py

@@ -1362,6 +1362,20 @@ def apply_patch(ctx, patch_file_path, format, dry_run, ignore_non_yang_tables, i
             patch_as_json = json.loads(text)
             patch = jsonpatch.JsonPatch(patch_as_json)
 
+        # convert IPv6 addresses to lowercase
+        for patch_line in patch:
+            if 'remove' == patch_line['op']:
+                match = re.search(r"(?P<prefix>/INTERFACE/\w+\|)(?P<ipv6_address>([a-fA-F0-9]{0,4}[:~]|::){1,7}[a-fA-F0-9]{0,4})"
+                                    "(?P<suffix>.*)", str.format(patch_line['path']))
+                if match:
+                    prefix = match.group('prefix')
+                    ipv6_address_str = match.group('ipv6_address')
+                    suffix = match.group('suffix')
+                    ipv6_address_str = ipv6_address_str.lower()
+                    click.secho("converted ipv6 address to lowercase {} with prefix {} in value: {}"
+                                .format(ipv6_address_str, prefix, patch_line['path']))
+                    patch_line['path'] = prefix + ipv6_address_str + suffix
+
         config_format = ConfigFormat[format.upper()]
         GenericUpdater().apply_patch(patch, config_format, verbose, dry_run, ignore_non_yang_tables, ignore_path)
 

tests/ip_config_input/patch_ipv6.test

@@ -0,0 +1,6 @@
+[
+    {
+        "path": "/INTERFACE/Ethernet12|FC00::1~1126", 
+        "op": "remove"
+    }
+]

tests/ip_config_test.py

@@ -1,3 +1,5 @@
+import json
+import jsonpatch
 import os
 import traceback
 from unittest import mock
@@ -8,6 +10,9 @@
 import show.main as show
 from utilities_common.db import Db
 
+test_path = os.path.dirname(os.path.abspath(__file__))
+ip_config_input_path = os.path.join(test_path, "ip_config_input")
+
 ERROR_MSG = "Error: IP address is not valid"
 
 class TestConfigIP(object):
@@ -157,6 +162,22 @@ def test_add_del_interface_shortened_ipv6_with_leading_zeros(self):
         assert result.exit_code != 0
         assert ('Ethernet68', '3000::1/64') not in db.cfgdb.get_table('INTERFACE')
 
+    def test_remove_interface_case_sensitive_mock_ipv6_w_apply_patch(self):
+        runner = CliRunner()
+        any_patch_as_json = [{"op": "remove", "path": "/INTERFACE/Ethernet12|FC00::1~1126"}]
+        any_patch = jsonpatch.JsonPatch(any_patch_as_json)
+        any_patch_as_text = json.dumps(any_patch_as_json)
+        ipv6_patch_file = os.path.join(ip_config_input_path, 'patch_ipv6.test')
+
+        # config apply-patch patch
+        mock_generic_updater = mock.Mock()
+        with mock.patch('config.main.GenericUpdater', return_value=mock_generic_updater):
+            with mock.patch('builtins.open', mock.mock_open(read_data=any_patch_as_text)):
+                result = runner.invoke(config.config.commands["apply-patch"], [ipv6_patch_file], catch_exceptions=False)
+        print(result.exit_code, result.output)
+        assert "converted ipv6 address to lowercase fc00::1~1126 with prefix /INTERFACE/Ethernet12| in value: /INTERFACE/Ethernet12|FC00::1~1126" in result.output
+
+
     @classmethod
     def teardown_class(cls):
         os.environ['UTILITIES_UNIT_TESTING'] = "0"