From b45d66a03659f8e4780b6b55e51edcbd2f6f012d Mon Sep 17 00:00:00 2001
From: MKhatibzadeh <32599707+masihkhatibzadeh99@users.noreply.github.com>
Date: Fri, 7 Feb 2025 18:13:43 +0330
Subject: [PATCH] fix: Ensure fqdn is treated as string in get_hostname_fqdn
 (#5993)

Explicitly cast fqdn to a string before processing.

Reference:https://github.com/canonical/cloud-init/commit/b45d66a03659f8e4780b6b55e51edcbd2f6f012d
Conflict:not change .github-cla-signers

Fixes GH-5989

Co-authored-by: masih.khatibzdeh <masih.khatibzadeh@snapp.cab>
---
 cloudinit/util.py            |  2 +-
 tests/unittests/test_util.py | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/cloudinit/util.py b/cloudinit/util.py
index 20b6e2e9ef4..bfcc9c8edba 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1215,7 +1215,7 @@ def get_hostname_fqdn(cfg, cloud, metadata_only=False):
     is_default = False
     if "fqdn" in cfg:
         # user specified a fqdn.  Default hostname then is based off that
-        fqdn = cfg["fqdn"]
+        fqdn = str(cfg["fqdn"])
         hostname = get_cfg_option_str(cfg, "hostname", fqdn.split(".")[0])
     else:
         if "hostname" in cfg and cfg["hostname"].find(".") > 0:
diff --git a/tests/unittests/test_util.py b/tests/unittests/test_util.py
index 8a107191b0e..7d2383f2dd6 100644
--- a/tests/unittests/test_util.py
+++ b/tests/unittests/test_util.py
@@ -799,6 +799,22 @@ def test_get_hostname_fqdn_from_without_fqdn_or_hostname(self):
             mock.call(metadata_only=False),
         ] == cloud.get_hostname.call_args_list

+    def test_get_hostname_fqdn_from_numeric_fqdn(self):
+        """When cfg fqdn is numeric, ensure it is treated as a string."""
+        hostname, fqdn, _ = util.get_hostname_fqdn(
+            cfg={"fqdn": 12345}, cloud=None
+        )
+        self.assertEqual("12345", hostname)
+        self.assertEqual("12345", fqdn)
+
+    def test_get_hostname_fqdn_from_numeric_fqdn_with_domain(self):
+        """When cfg fqdn is numeric with a domain, ensure correct parsing."""
+        hostname, fqdn, _ = util.get_hostname_fqdn(
+            cfg={"fqdn": "12345.example.com"}, cloud=None
+        )
+        self.assertEqual("12345", hostname)
+        self.assertEqual("12345.example.com", fqdn)
+
     def test_get_hostname_fqdn_from_passes_metadata_only_to_cloud(self):
         """Calls to cloud.get_hostname pass the metadata_only parameter."""
         cloud = mock.MagicMock()
-- 
2.33.0

