Merge pull request #5039 from konidev20/fix-gh-4806-forget-add-reason-for-oldest-snapshot-retained

forget: indicate why the oldest snapshot in a group is kept

doc/060_forget.rst

@@ -214,7 +214,8 @@ The ``forget`` command accepts the following policy options:
     run) and these snapshots will hence not be removed.
 
 .. note:: If there are not enough snapshots to keep one for each duration related
-    ``--keep-{within-,}*`` option, the oldest snapshot is kept additionally.
+    ``--keep-{within-,}*`` option, the oldest snapshot is kept additionally and 
+    marked as ``oldest`` in the output (e.g. ``oldest hourly snapshot``).
 
 .. note:: Specifying ``--keep-tag ''`` will match untagged snapshots only.
 

internal/restic/snapshot_policy.go

@@ -256,6 +256,9 @@ func ApplyPolicy(list Snapshots, p ExpirePolicy) (keep, remove Snapshots, reason
 				if val != b.Last || nr == len(list)-1 {
 					debug.Log("keep %v %v, bucker %v, val %v\n", cur.Time, cur.id.Str(), i, val)
 					keepSnap = true
+					if val == b.Last && nr == len(list)-1 {
+						b.reason = fmt.Sprintf("oldest %v", b.reason)
+					}
 					buckets[i].Last = val
 					if buckets[i].Count > 0 {
 						buckets[i].Count--
@@ -275,6 +278,9 @@ func ApplyPolicy(list Snapshots, p ExpirePolicy) (keep, remove Snapshots, reason
 					if val != b.Last || nr == len(list)-1 {
 						debug.Log("keep %v, time %v, ID %v, bucker %v, val %v %v\n", b.reason, cur.Time, cur.id.Str(), i, val, b.Last)
 						keepSnap = true
+						if val == b.Last && nr == len(list)-1 {
+							b.reason = fmt.Sprintf("oldest %v", b.reason)
+						}
 						bucketsWithin[i].Last = val
 						keepSnapReasons = append(keepSnapReasons, fmt.Sprintf("%v %v", b.reason, b.Within))
 					}

internal/restic/testdata/policy_keep_snapshots_16

@@ -68,7 +68,7 @@
         "paths": null
       },
       "matches": [
-        "yearly snapshot"
+        "oldest yearly snapshot"
       ],
       "counters": {
         "yearly": 6

internal/restic/testdata/policy_keep_snapshots_17

@@ -214,7 +214,7 @@
         "paths": null
       },
       "matches": [
-        "yearly snapshot"
+        "oldest yearly snapshot"
       ],
       "counters": {
         "yearly": 6

internal/restic/testdata/policy_keep_snapshots_35

@@ -165,7 +165,7 @@
         "paths": null
       },
       "matches": [
-        "yearly within 9999y"
+        "oldest yearly within 9999y"
       ],
       "counters": {}
     }

internal/restic/testdata/policy_keep_snapshots_39

@@ -238,8 +238,8 @@
         "paths": null
       },
       "matches": [
-        "monthly snapshot",
-        "yearly snapshot"
+        "oldest monthly snapshot",
+        "oldest yearly snapshot"
       ],
       "counters": {
         "monthly": -1,