From c48069ce8814b06a1204b3e985ba02780a9a6ca8 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <me@cschwarz.com>
Date: Thu, 5 Oct 2017 20:34:35 +0200
Subject: [PATCH] retention grid: interva length monotonicity: exception for
 keep=all

fixes #6
---
 cmd/config_prune_grid.go | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/cmd/config_prune_grid.go b/cmd/config_prune_grid.go
index 0556e55..9af89c1 100644
--- a/cmd/config_prune_grid.go
+++ b/cmd/config_prune_grid.go
@@ -80,13 +80,22 @@ func parseGridPrunePolicy(e map[string]interface{}) (p *GridPrunePolicy, err err
 	// Assert intervals are of increasing length (not necessarily required, but indicates config mistake)
 	lastDuration := time.Duration(0)
 	for i := range intervals {
+
 		if intervals[i].Length < lastDuration {
-			err = fmt.Errorf("retention grid interval length must be monotonically increasing:"+
-				"interval %d is shorter than %d", i+1, i)
+			// If all intervals before were keep=all, this is ok
+			allPrevKeepCountAll := true
+			for j := i - 1; allPrevKeepCountAll && j >= 0; j-- {
+				allPrevKeepCountAll = intervals[j].KeepCount == util.RetentionGridKeepCountAll
+			}
+			if allPrevKeepCountAll {
+				goto isMonotonicIncrease
+			}
+			err = errors.New("retention grid interval length must be monotonically increasing")
 			return
-		} else {
-			lastDuration = intervals[i].Length
 		}
+	isMonotonicIncrease:
+		lastDuration = intervals[i].Length
+
 	}
 	p.RetentionGrid = util.NewRetentionGrid(intervals)