users: schema permit empty list to indicate create no users

When defining json schema in a63f45f7, we were a bit too strict by
setting `minItems: 1` on the `users:` list.

This schema definition regressed the ability to prevent default_user
creation with user-data.  Remove that schema constraint because the
code already supports this case.

4 files changed, 38 insertions, 29 deletions

diff --git a/cloudinit/config/cc_users_groups.py b/cloudinit/config/cc_users_groups.py
index 52f0b844..d64cae9e 100644
--- a/cloudinit/config/cc_users_groups.py
+++ b/cloudinit/config/cc_users_groups.py
@@ -146,6 +146,12 @@ meta: MetaSchema = {
           sudo: null
         """
         ),
+        dedent(
+            """\
+        # Avoid creating any ``default_user``.
+        users: []
+        """
+        ),
     ],
     "frequency": PER_INSTANCE,
     "activate_by_schema_keys": [],
diff --git a/cloudinit/config/schemas/schema-cloud-config-v1.json b/cloudinit/config/schemas/schema-cloud-config-v1.json
index 2a2d8631..3c2b90f9 100644
--- a/cloudinit/config/schemas/schema-cloud-config-v1.json
+++ b/cloudinit/config/schemas/schema-cloud-config-v1.json
@@ -3079,8 +3079,7 @@
                 "$ref": "#/$defs/users_groups.user"
               }
             ]
-          },
-          "minItems": 1
+          }
         }
       }
     },
diff --git a/tests/unittests/config/test_cc_users_groups.py b/tests/unittests/config/test_cc_users_groups.py
index 48f80ea8..635e0b63 100644
--- a/tests/unittests/config/test_cc_users_groups.py
+++ b/tests/unittests/config/test_cc_users_groups.py
@@ -358,7 +358,9 @@ class TestUsersGroupsSchema:
             ({"users": "oldstyle,default"}, does_not_raise(), None),
             ({"users": ["default"]}, does_not_raise(), None),
             ({"users": ["default", ["aaa", "bbb"]]}, does_not_raise(), None),
-            # no default user creation
+            # no user creation at all
+            ({"users": []}, does_not_raise(), None),
+            # different default user creation
             ({"users": ["foobar"]}, does_not_raise(), None),
             (
                 {"users": [{"name": "bbsw", "lock-passwd": True}]},
diff --git a/tests/unittests/distros/test_user_data_normalize.py b/tests/unittests/distros/test_user_data_normalize.py
index 67ea024b..fc9d72f1 100644
--- a/tests/unittests/distros/test_user_data_normalize.py
+++ b/tests/unittests/distros/test_user_data_normalize.py
@@ -44,7 +44,7 @@ class TestUGNormalize(TestCase):
                 {"bob": "users2"},
             ]
         }
-        (_users, groups) = self._norm(g, distro)
+        _users, groups = self._norm(g, distro)
         self.assertIn("ubuntu", groups)
         ub_members = groups["ubuntu"]
         self.assertEqual(sorted(["foo", "bar"]), sorted(ub_members))
@@ -57,7 +57,7 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "groups": ["bob"],
         }
-        (users, groups) = self._norm(ug_cfg, distro)
+        users, groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", groups)
         self.assertEqual({}, users)
 
@@ -66,7 +66,7 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "groups": "bob,joe,steve",
         }
-        (users, groups) = self._norm(ug_cfg, distro)
+        users, groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", groups)
         self.assertIn("joe", groups)
         self.assertIn("steve", groups)
@@ -75,7 +75,7 @@ class TestUGNormalize(TestCase):
     def test_more_groups(self):
         distro = self._make_distro("ubuntu")
         ug_cfg = {"groups": ["bob", "joe", "steve"]}
-        (users, groups) = self._norm(ug_cfg, distro)
+        users, groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", groups)
         self.assertIn("joe", groups)
         self.assertIn("steve", groups)
@@ -90,7 +90,7 @@ class TestUGNormalize(TestCase):
                 "steve": [],
             }
         }
-        (users, groups) = self._norm(ug_cfg, distro)
+        users, groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", groups)
         self.assertEqual(["s"], groups["bob"])
         self.assertEqual([], groups["joe"])
@@ -105,21 +105,21 @@ class TestUGNormalize(TestCase):
                 "default": True,
             }
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         ug_cfg = {
             "users": {
                 "default": "yes",
             }
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         ug_cfg = {
             "users": {
                 "default": "1",
             }
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
 
     def test_users_simple_dict_no(self):
@@ -129,14 +129,14 @@ class TestUGNormalize(TestCase):
                 "default": False,
             }
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertEqual({}, users)
         ug_cfg = {
             "users": {
                 "default": "no",
             }
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertEqual({}, users)
 
     def test_users_simple_csv(self):
@@ -144,7 +144,7 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "users": "joe,bob",
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("joe", users)
         self.assertIn("bob", users)
         self.assertEqual({"default": False}, users["joe"])
@@ -155,29 +155,31 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "users": ["joe", "bob"],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("joe", users)
         self.assertIn("bob", users)
         self.assertEqual({"default": False}, users["joe"])
         self.assertEqual({"default": False}, users["bob"])
+        users, _groups = self._norm({"users": []}, distro)
+        self.assertEqual({}, users)
 
     def test_users_old_user(self):
         distro = self._make_distro("ubuntu", bcfg)
         ug_cfg = {"user": "zetta", "users": "default"}
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertNotIn("bob", users)  # Bob is not the default now, zetta is
         self.assertIn("zetta", users)
         self.assertTrue(users["zetta"]["default"])
         self.assertNotIn("default", users)
         ug_cfg = {"user": "zetta", "users": "default, joe"}
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertNotIn("bob", users)  # Bob is not the default now, zetta is
         self.assertIn("joe", users)
         self.assertIn("zetta", users)
         self.assertTrue(users["zetta"]["default"])
         self.assertNotIn("default", users)
         ug_cfg = {"user": "zetta", "users": ["bob", "joe"]}
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         self.assertIn("joe", users)
         self.assertIn("zetta", users)
@@ -189,7 +191,7 @@ class TestUGNormalize(TestCase):
                 "joe": True,
             },
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         self.assertIn("joe", users)
         self.assertIn("zetta", users)
@@ -197,10 +199,10 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "user": "zetta",
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("zetta", users)
         ug_cfg = {}
-        (users, groups) = self._norm(ug_cfg, distro)
+        users, groups = self._norm(ug_cfg, distro)
         self.assertEqual({}, users)
         self.assertEqual({}, groups)
 
@@ -209,7 +211,7 @@ class TestUGNormalize(TestCase):
         ug_cfg = {
             "users": [{"name": "default", "blah": True}],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         self.assertEqual(
             ",".join(distro.get_default_user()["groups"]),
@@ -225,7 +227,7 @@ class TestUGNormalize(TestCase):
                 "default",
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         (name, config) = ug_util.extract_default(users)
         self.assertEqual(name, "bob")
@@ -252,7 +254,7 @@ class TestUGNormalize(TestCase):
                 "default",
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("bob", users)
         self.assertEqual(
             ",".join(distro.get_default_user()["groups"]),
@@ -268,7 +270,7 @@ class TestUGNormalize(TestCase):
                 {"name": "bob"},
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("joe", users)
         self.assertIn("bob", users)
         self.assertEqual({"tr_me": True, "default": False}, users["joe"])
@@ -282,7 +284,7 @@ class TestUGNormalize(TestCase):
                 {"name": "bob"},
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         self.assertIn("joe", users)
         self.assertIn("bob", users)
         self.assertEqual({"default": False}, users["joe"])
@@ -299,7 +301,7 @@ class TestUGNormalize(TestCase):
                 {"name": "joe", "snapuser": "joe@joe.com"},
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         for (user, config) in users.items():
             print("user=%s config=%s" % (user, config))
             username = distro.create_user(user, **config)
@@ -319,7 +321,7 @@ class TestUGNormalize(TestCase):
                 {"name": "joe", "snapuser": "joe@joe.com", "known": True},
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         for (user, config) in users.items():
             print("user=%s config=%s" % (user, config))
             username = distro.create_user(user, **config)
@@ -350,7 +352,7 @@ class TestUGNormalize(TestCase):
                 {"name": "joe", "groups": "users", "create_groups": True},
             ],
         }
-        (users, _groups) = self._norm(ug_cfg, distro)
+        users, _groups = self._norm(ug_cfg, distro)
         for (user, config) in users.items():
             print("user=%s config=%s" % (user, config))
             distro.add_user(user, **config)