MT#55988 buildinfo: fix migration of timestamp

* restore info from build.json files

Change-Id: Iaeb4d6dd2262c471197ef0de7e20c9d25e5f44e1

buildinfo/migrations/0004_buildinfo_datetime.py

@@ -10,6 +10,7 @@ def migrate_timestamps(apps, schema_editor):
     BuildInfo = apps.get_model("buildinfo", "BuildInfo")
     for info in BuildInfo.objects.all():
         info.datetime = get_datetime(info.timestamp)
+        info.save()
 
 
 class Migration(migrations.Migration):

buildinfo/migrations/0005_restore_timestamp_value.py

@@ -0,0 +1,31 @@
+# Generated by Django 3.2.15 on 2022-12-16 15:12
+import json
+
+from django.conf import settings
+from django.db import migrations
+
+from buildinfo.utils import get_datetime
+
+
+def restore_timestamps(apps, schema_editor):
+    BuildInfo = apps.get_model("buildinfo", "BuildInfo")
+    for info in BuildInfo.objects.all():
+        build_path = settings.JBI_BASEDIR.joinpath(
+            info.jobname, str(info.buildnumber), "build.json"
+        )
+        if build_path.exists():
+            with build_path.open("r") as f:
+                build_info = json.load(f)
+            info.datetime = get_datetime(build_info["timestamp"])
+            info.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("buildinfo", "0004_buildinfo_datetime"),
+    ]
+
+    operations = [
+        migrations.RunPython(restore_timestamps),
+    ]