Fix reports 500 on MySQL; enforcement report asset context

plugins/geenforce/api/routes.py

@@ -11,6 +11,7 @@ Two audiences:
 import ipaddress
 import os
 import time
+from datetime import datetime
 from functools import wraps
 
 from flask import Blueprint, request, Response, send_file, current_app, g
@@ -24,6 +25,9 @@ from shopdb.api import (
 
 SHAREROOT_SETTING = 'geenforce_share_root'
 
+# Sort floor for revisions with no lastseenat (they sort last regardless).
+_EPOCH = datetime.min
+
 from ..models import (
     ManifestScope, ManifestEntry, ManifestPublishedVersion,
     ManifestEnforcementReport, ManifestEnforcementResult, ManifestPayload,
@@ -1037,12 +1041,19 @@ def _attach_backup_state(facts, hostnames):
         return
     rows = (BackupRevision.query
             .filter(BackupRevision.sourcehostname.in_(hostnames))
-            .order_by(BackupRevision.lastseenat.desc().nullslast())
             .all())
+    # Newest confirmed first, ordered HERE rather than in SQL: putting nulls
+    # last needs ORDER BY ... NULLS LAST, which SQLite accepts and MySQL
+    # rejects outright - so the query passed every test and 500'd on the real
+    # database. Row counts here are one per host per kind, so sorting in Python
+    # costs nothing.
+    rows.sort(key=lambda revision: (revision.lastseenat is not None,
+                                    revision.lastseenat or _EPOCH),
+              reverse=True)
     for revision in rows:
         key = (revision.sourcehostname or '').lower()
         entry = facts.get(key)
-        # First row per host wins: ordered newest-confirmed first.
+        # First row per host wins.
         if entry and entry['backuplastseen'] is None:
             entry['backupkind'] = revision.backupkind
             entry['backuplastseen'] = (

tests/test_plugins/test_geenforce_publish_gate.py

@@ -151,3 +151,45 @@ def test_hosts_below_libversion_reports_the_floor(db):
         'gea-shopfloor-cmm', 'runtime', '2.6')
     assert hosts == ['A', 'B']
     assert floor == '2.3'
+
+
+# -- backup state on the reports table ---------------------------------------
+
+def test_backup_state_prefers_the_newest_confirmed_revision(db):
+    """A host with several revisions shows the most recently CONFIRMED one, and
+    a revision that has never been confirmed (lastseenat NULL) never wins.
+
+    Ordering happens in Python on purpose. Doing it in SQL needs
+    ORDER BY ... NULLS LAST, which SQLite accepts and MySQL rejects outright -
+    so it passed every test here and returned a 500 against the real database.
+    """
+    from datetime import timedelta
+
+    from plugins.backups.models import BackupRevision
+    from plugins.geenforce.api.routes import _attach_backup_state
+    from shopdb.api import Asset, AssetType
+
+    assettype = AssetType.query.first()
+    if not assettype:
+        assettype = AssetType(assettype='computer')
+        db.session.add(assettype)
+        db.session.flush()
+    asset = Asset(assetnumber='PC-1', name='PC-1',
+                  assettypeid=assettype.assettypeid)
+    db.session.add(asset)
+    db.session.flush()
+
+    now = datetime.now(timezone.utc).replace(tzinfo=None)
+    for kind, lastseen in (('ntlars', now - timedelta(days=9)),
+                           ('udc', now),
+                           ('files', None)):
+        db.session.add(BackupRevision(
+            assetid=asset.assetid, backupkind=kind, contenthash=kind * 8,
+            sourcehostname='WJPC01', lastseenat=lastseen, createdat=now))
+    db.session.flush()
+
+    facts = {'wjpc01': {'backupkind': None, 'backuplastseen': None}}
+    _attach_backup_state(facts, {'WJPC01'})
+
+    assert facts['wjpc01']['backupkind'] == 'udc'
+    assert facts['wjpc01']['backuplastseen'] is not None