Merge ~alexsander-souza/maas:lp2063835_to_3_5 into maas:3.5

[Alexsander de Souza]

fix(bootresources): handle incomplete files

if a resource was partially downloaded at the time of the migration,
discard the large object and schedule it for downloading again.

(cherry picked from commit 811612c009dc8c095c3b99062563801e3a991967)

[Alexsander de Souza (alexsander-souza)]

self-approve back-port

review: Approve

[MAAS Lander (maas-lander)]

UNIT TESTS
-b lp2063835_to_3_5 lp:~alexsander-souza/maas/+git/maas into -b 3.5 lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: f404a65479d80959847e1131d467a7af15561b0b

review: Approve

diff --git a/src/maasserver/bootresources.py b/src/maasserver/bootresources.py
index 1f3562f..2e9678e 100644
--- a/src/maasserver/bootresources.py
+++ b/src/maasserver/bootresources.py
@@ -1272,13 +1272,12 @@ def export_images_from_db(region: RegionController, target_dir: Path):
                 )
 
             total_size = file.largefile.total_size
-            if file.largefile.size != total_size:
-                msg(f"skipping, size is {file.largefile.size} of {total_size}")
-                oids_to_delete.add(file.largefile.content.oid)
-                continue
-
             if lfile.valid:
                 msg("skipping, file already present")
+                set_sync_status()
+            elif file.largefile.size != total_size:
+                # we need to download this again
+                msg(f"ignoring, size is {file.largefile.size} of {total_size}")
             else:
                 lfile.unlink()
                 msg("writing")
@@ -1287,10 +1286,9 @@ def export_images_from_db(region: RegionController, target_dir: Path):
                     lfile.store() as dfd,
                 ):
                     shutil.copyfileobj(sfd, dfd)
-                    oids_to_delete.add(file.largefile.content.oid)
-
-            set_sync_status()
+                set_sync_status()
 
+            oids_to_delete.add(file.largefile.content.oid)
             largefile_ids_to_delete.add(file.largefile_id)
             # need to unset it because the post-delete signal will otherwise
             # try to delete the largefile object, which is already handled
diff --git a/src/tests/maasserver/test_bootresources.py b/src/tests/maasserver/test_bootresources.py
index 2daeb48..5b14735 100644
--- a/src/tests/maasserver/test_bootresources.py
+++ b/src/tests/maasserver/test_bootresources.py
@@ -196,6 +196,34 @@ class TestExportImagesFromDB:
             cursor.execute("SELECT loid FROM pg_largeobject")
             assert cursor.fetchall() == []
 
+    def test_partial_largfile(self, controller, image_store_dir, factory):
+        resource = factory.make_BootResource(
+            name="ubuntu/jammy",
+            architecture="s390x/generic",
+        )
+        resource_set = factory.make_BootResourceSet(
+            resource=resource,
+            version="20230901",
+            label="stable",
+        )
+        resource_file = make_boot_resource_file_with_content_largefile(
+            factory,
+            resource_set=resource_set,
+            filename="boot-initrd",
+            content=b"some content",
+        )
+        largefile = resource_file.largefile
+        largefile.size = 0
+        largefile.save()
+
+        export_images_from_db(controller, image_store_dir)
+
+        assert reload_object(largefile) is None
+        # largeobject also gets deleted
+        with connection.cursor() as cursor:
+            cursor.execute("SELECT loid FROM pg_largeobject")
+            assert cursor.fetchall() == []
+
     def test_no_largefile_ignore(self, controller, image_store_dir, factory):
         resource = factory.make_BootResource(
             name="ubuntu/jammy",