Merge "Always return a sorted list of drivers for configs" into stable/newton

glance_store/backend.py

@@ -132,7 +132,12 @@ def _list_opts():
     driver_opts = []
     mgr = extension.ExtensionManager('glance_store.drivers')
     # NOTE(zhiyan): Handle available drivers entry_points provided
-    drivers = [ext.name for ext in mgr]
+    # NOTE(nikhil): Return a sorted list of drivers so that the oslo config
+    # generator can use that order to keep generating configuration file in a
+    # consistent manner. If this order is not preserved, in some cases the
+    # downstream packagers may see a long diff of the changes though not
+    # relevant as only order has changed. See some more details at bug 1619487.
+    drivers = sorted([ext.name for ext in mgr])
     handled_drivers = []  # Used to handle backwards-compatible entries
     for store_entry in drivers:
         driver_cls = _load_store(None, store_entry, False)

releasenotes/notes/sorted-drivers-for-configs-a905f07d3bf9c973.yaml

@@ -0,0 +1,16 @@
+---
+prelude: >
+    Return list of store drivers in sorted order for
+    generating configs. More info in ``Upgrade Notes``
+    and ``Bug Fixes`` section.
+upgrade:
+  - This version of glance_store will result in Glance
+    generating the configs in a sorted (deterministic)
+    order. So, preferably store releases on or after this
+    should be used for generating any new configs if the
+    mismatched ordering of the configs results in an issue
+    in your environment.
+fixes:
+  - Bug 1619487 is fixed which was causing random order of
+    the generation of configs in Glance. See ``upgrade``
+    section for more details.