From 076aaac87f6478a95bfb156bd674dfd0558f6782 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Elvira=20Garc=C3=ADa?= <egarciar@redhat.com>
Date: Thu, 1 Aug 2024 13:21:42 +0200
Subject: [PATCH] Add a function to trim scope out of ipv6 addr

Currently, is_valid_ipv6 accepts ipv6 addresses with scope. However,
there are functions that won't accept an address with scope. An example
of this would be the netaddress.IPAdress() function used in Neutron.

Related-Bug: #2073894
Change-Id: If2757dfc91f5b4c8257dee49d6da1e216b3e7cd8
---
 oslo_utils/netutils.py                        | 25 +++++++++++++++++++
 oslo_utils/tests/test_netutils.py             | 10 ++++++++
 .../notes/bug-2073894-2e11ca85984b7bb7.yaml   |  7 ++++++
 3 files changed, 42 insertions(+)
 create mode 100644 releasenotes/notes/bug-2073894-2e11ca85984b7bb7.yaml

diff --git a/oslo_utils/netutils.py b/oslo_utils/netutils.py
index 017a416a..6e4c54c1 100644
--- a/oslo_utils/netutils.py
+++ b/oslo_utils/netutils.py
@@ -17,6 +17,7 @@
 Network-related utilities and helper functions.
 """
 
+import ipaddress
 import logging
 import os
 import re
@@ -148,6 +149,30 @@ def is_valid_ipv6(address):
         return False
 
 
+def get_noscope_ipv6(address):
+    """Take an IPv6 address and trim scope out if present.
+
+    :param address: Value to change
+    :type address: string
+    :returns: string
+
+    .. versionadded: 7.3.0:
+    """
+    # TODO(egarciar): Scope was added for IPv6Address on Python 3.9. Same for
+    # the removesuffix str method. Remove try/except when minimum required
+    # version for Python is 3.9
+    try:
+        _ipv6 = ipaddress.IPv6Address(address)
+        if _ipv6.scope_id:
+            address = address.removesuffix('%' + _ipv6.scope_id)
+        return address
+    except (ipaddress.AddressValueError, AttributeError):
+        if is_valid_ipv6(address):
+            parts = address.rsplit("%", 1)
+            return parts[0]
+        raise
+
+
 def is_valid_cidr(address):
     """Verify that address represents a valid CIDR address.
 
diff --git a/oslo_utils/tests/test_netutils.py b/oslo_utils/tests/test_netutils.py
index 82212991..b75f2f95 100644
--- a/oslo_utils/tests/test_netutils.py
+++ b/oslo_utils/tests/test_netutils.py
@@ -212,6 +212,16 @@ class NetworkUtilsTest(test_base.BaseTestCase):
 
         self.assertFalse(netutils.is_valid_ipv6(''))
 
+    def test_get_noscope_ipv6(self):
+        self.assertEqual('2001:db8::ff00:42:8329',
+                         netutils.get_noscope_ipv6('2001:db8::ff00:42:8329%1'))
+        self.assertEqual('ff02::5678',
+                         netutils.get_noscope_ipv6('ff02::5678%eth0'))
+        self.assertEqual('fe80::1', netutils.get_noscope_ipv6('fe80::1%eth0'))
+        self.assertEqual('::1', netutils.get_noscope_ipv6('::1%eth0'))
+        self.assertEqual('::1', netutils.get_noscope_ipv6('::1'))
+        self.assertRaises(ValueError, netutils.get_noscope_ipv6, '::132:::')
+
     def test_escape_ipv6(self):
         self.assertEqual('[1234::1234]', netutils.escape_ipv6('1234::1234'))
         self.assertEqual('127.0.0.1', netutils.escape_ipv6('127.0.0.1'))
diff --git a/releasenotes/notes/bug-2073894-2e11ca85984b7bb7.yaml b/releasenotes/notes/bug-2073894-2e11ca85984b7bb7.yaml
new file mode 100644
index 00000000..1e015bfa
--- /dev/null
+++ b/releasenotes/notes/bug-2073894-2e11ca85984b7bb7.yaml
@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    `Bug #2073894 <https://bugs.launchpad.net/oslo.utils/+bug/2073894>`_:
+    Added the netutils.get_noscope_ipv6() function in order to fix errors
+    related to IPv6 address formatting that can happen when using an IPv6
+    defined with scope.