oem: skip listing OEM metapkgs on ubuntu-server

OEM meta-packages have an attribute stating if they want the OEM kernel
or the "default" kernel to be installed alongside them.

That said, in the OEM archive, they expect the "default" OEM kernel to
be the HWE kernel. This is only true for ubuntu-desktop. Let's not
install OEM meta-packages on ubuntu-server for now.

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

subiquity/server/controllers/oem.py

@@ -94,6 +94,16 @@ class OEMController(SubiquityController):
     async def load_metapackages_list(self, context) -> None:
         with context.child("wait_apt"):
             await self._wait_apt.wait()
+
+        # Skip looking for OEM meta-packages if we are running ubuntu-server.
+        # OEM meta-packages expect the default kernel flavor to be HWE (which
+        # is only true for ubuntu-desktop).
+        if self.app.base_model.source.current.variant == "server":
+            log.debug("not listing OEM meta-packages since we are installing"
+                      " ubuntu-server")
+            self.model.metapkgs = []
+            return
+
         apt = self.app.controllers.Mirror.final_apt_configurer
         try:
             async with apt.overlay() as d:

subiquity/tests/api/test_api.py

@@ -1707,11 +1707,13 @@ class TestOEM(TestAPI):
                 resp = await inst.get('/oem', wait=True)
                 self.assertEqual(expected_pkgs, resp['metapackages'])
 
-    async def test_listing_certified(self):
-        expected_pkgs = ['oem-somerville-tentacool-meta']
+    async def _test_listing_certified(self, source_id: str,
+                                      expected: List[str]):
         with patch.dict(os.environ, {'SUBIQUITY_DEBUG': 'has-drivers'}):
-            async with start_server('examples/simple.json') as inst:
-                await inst.post('/source', source_id='ubuntu-server')
+            args = ['--source-catalog', 'examples/mixed-sources.yaml']
+            config = 'examples/simple.json'
+            async with start_server(config, extra_args=args) as inst:
+                await inst.post('/source', source_id=source_id)
                 names = ['locale', 'keyboard', 'source', 'network', 'proxy',
                          'mirror', 'storage']
                 await inst.post('/meta/mark_configured', endpoint_names=names)
@@ -1720,7 +1722,19 @@ class TestOEM(TestAPI):
                 await inst.get('/meta/status', cur='NEEDS_CONFIRMATION')
 
                 resp = await inst.get('/oem', wait=True)
-                self.assertEqual(expected_pkgs, resp['metapackages'])
+                self.assertEqual(expected, resp['metapackages'])
+
+    async def test_listing_certified_ubuntu_server(self):
+        # Listing of OEM meta-packages is intentionally disabled on
+        # ubuntu-server.
+        await self._test_listing_certified(
+                source_id='ubuntu-server',
+                expected=[])
+
+    async def test_listing_certified_ubuntu_desktop(self):
+        await self._test_listing_certified(
+                source_id='ubuntu-desktop',
+                expected=['oem-somerville-tentacool-meta'])
 
 
 class TestSource(TestAPI):