install: handle nvidia driver version != component version

Often (always?) the `ubuntu-drivers list --recommended` version is going
to be newer than what's actually available as a pc-kernel component.
Handle that version mismatch.

subiquity/server/controllers/install.py

@@ -675,15 +675,29 @@ def kernel_components(self) -> List[str]:
             return []
         info: VariationInfo = self.app.controllers.Filesystem._info
         kernel_components = info.available_kernel_components
+        nvidia_driver_offered: bool = False
+        # for first pass, accept the matching version, if that's an option
         for driver in sorted(self.app.controllers.Drivers.drivers, reverse=True):
             m = re.fullmatch("nvidia-driver-([0-9]+)", driver)
             if not m:
                 continue
+            nvidia_driver_offered = True
             v = m.group(1)
             ko = f"nvidia-{v}-ko"
             user = f"nvidia-{v}-user"
             if ko in kernel_components and user in kernel_components:
                 return [ko, user]
+        # if we don't match there, accept the newest reasonable version
+        if nvidia_driver_offered:
+            for component in sorted(kernel_components, reverse=True):
+                m = re.fullmatch("nvidia-([0-9]+)-ko", component)
+                if not m:
+                    continue
+                ko = component
+                v = m.group(1)
+                user = f"nvidia-{v}-user"
+                if user in kernel_components:
+                    return [ko, user]
         return []
 
     @with_context(

subiquity/server/controllers/tests/test_install.py

@@ -396,8 +396,12 @@ def setUp(self):
             (["nvidia-510-ko"], ["nvidia-driver-510"], []),
             # missing ko component
             (["nvidia-510-user"], ["nvidia-driver-510"], []),
-            # wrong driver version
-            (["nvidia-510-ko", "nvidia-510-user"], ["nvidia-driver-999"], []),
+            # mismatched component versions, nothing usable available
+            (
+                ["nvidia-2-ko", "nvidia-1-user"],
+                ["nvidia-driver-999"],
+                [],
+            ),
             # match
             (
                 ["nvidia-510-ko", "nvidia-510-user"],
@@ -415,6 +419,24 @@ def setUp(self):
                 ["nvidia-driver-2", "nvidia-driver-1"],
                 ["nvidia-2-ko", "nvidia-2-user"],
             ),
+            # wrong driver version
+            (
+                ["nvidia-510-ko", "nvidia-510-user"],
+                ["nvidia-driver-999"],
+                ["nvidia-510-ko", "nvidia-510-user"],
+            ),
+            # wrong driver version, use newer
+            (
+                ["nvidia-1-ko", "nvidia-2-user", "nvidia-2-ko", "nvidia-1-user"],
+                ["nvidia-driver-999"],
+                ["nvidia-2-ko", "nvidia-2-user"],
+            ),
+            # mismatched component versions, something usable available
+            (
+                ["nvidia-1-ko", "nvidia-2-ko", "nvidia-1-user"],
+                ["nvidia-driver-999"],
+                ["nvidia-1-ko", "nvidia-1-user"],
+            ),
         )
     )
     def test_kernel_components(self, comps, drivers, expected):