mirror: do not assign an elected mirror automatically

When Subiquity starts, we no longer assign the elected mirror. This
means that marking the mirror model configured without selecting a
mirror is possible, and will cause trouble during install.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

subiquity/models/mirror.py

@@ -86,9 +86,9 @@ class MirrorModel(object):
     def __init__(self):
         self.config = copy.deepcopy(DEFAULT)
         self.disabled_components: Set[str] = set()
-        self.primary_elected = PrimarySection.new_from_default(parent=self)
+        self.primary_elected: Optional[PrimarySection] = None
         self.primary_candidates: List[PrimarySection] = [
-            self.primary_elected,
+            PrimarySection.new_from_default(parent=self),
         ]
 
         self.primary_staged: Optional[PrimarySection] = None
@@ -104,8 +104,6 @@ class MirrorModel(object):
             self.primary_candidates = [
                     PrimarySection(data.pop("primary"), parent=self)
                     ]
-            # TODO do not mark primary elected.
-            self.primary_elected = self.primary_candidates[0]
         merge_config(self.config, data)
 
     def _get_apt_config_common(self) -> Dict[str, Any]:
@@ -124,6 +122,8 @@ class MirrorModel(object):
         return config
 
     def get_apt_config_elected(self) -> Dict[str, Any]:
+        assert self.primary_elected is not None
+
         config = self._get_apt_config_common()
         config["primary"] = self.primary_elected.config
         return config
@@ -169,5 +169,9 @@ class MirrorModel(object):
 
     def make_autoinstall(self):
         config = self._get_apt_config_common()
-        config["primary"] = self.primary_elected.config
+        if self.primary_elected is not None:
+            config["primary"] = self.primary_elected.config
+        else:
+            # In an offline autoinstall, there is no elected mirror.
+            config["primary"] = self.primary_candidates[0].config
         return config

subiquity/models/tests/test_mirror.py

@@ -79,11 +79,13 @@ class TestPrimarySection(unittest.TestCase):
 class TestMirrorModel(unittest.TestCase):
     def setUp(self):
         self.model = MirrorModel()
+        self.candidate = self.model.primary_candidates[0]
+        self.model.primary_staged = self.candidate
 
     def test_set_country(self):
         self.model.set_country("CC")
         self.assertIn(
-            self.model.primary_candidates[0].get_mirror(),
+            self.candidate.get_mirror(),
             [
                 "http://CC.archive.ubuntu.com/ubuntu",
                 "http://CC.ports.ubuntu.com/ubuntu-ports",
@@ -96,20 +98,22 @@ class TestMirrorModel(unittest.TestCase):
         self.assertEqual(candidate.get_mirror(), "http://mymirror.invalid/")
 
     def test_default_disable_components(self):
-        config = self.model.get_apt_config_elected()
+        config = self.model.get_apt_config_staged()
         self.assertEqual([], config['disable_components'])
 
     def test_from_autoinstall(self):
         # autoinstall loads to the config directly
         data = {'disable_components': ['non-free']}
         self.model.load_autoinstall_data(data)
-        config = self.model.get_apt_config_elected()
+        self.candidate = self.model.primary_candidates[0]
+        self.model.primary_staged = self.candidate
+        config = self.model.get_apt_config_staged()
         self.assertEqual(['non-free'], config['disable_components'])
 
     def test_disable_add(self):
         expected = ['things', 'stuff']
         self.model.disable_components(expected.copy(), add=True)
-        actual = self.model.get_apt_config_elected()['disable_components']
+        actual = self.model.get_apt_config_staged()['disable_components']
         actual.sort()
         expected.sort()
         self.assertEqual(expected, actual)
@@ -119,7 +123,7 @@ class TestMirrorModel(unittest.TestCase):
         to_remove = ['things', 'stuff']
         expected = ['a', 'b']
         self.model.disable_components(to_remove, add=False)
-        actual = self.model.get_apt_config_elected()['disable_components']
+        actual = self.model.get_apt_config_staged()['disable_components']
         actual.sort()
         expected.sort()
         self.assertEqual(expected, actual)

subiquity/server/controllers/tests/test_mirror.py

@@ -52,6 +52,8 @@ class TestMirrorController(unittest.IsolatedAsyncioTestCase):
 
     def test_make_autoinstall(self):
         self.controller.model = MirrorModel()
+        self.controller.model.primary_elected = \
+            self.controller.model.primary_candidates[0]
         config = self.controller.make_autoinstall()
         self.assertIn("disable_components", config.keys())
         self.assertIn("primary", config.keys())