add retention default and wire in s3 prune

pkg/cli/cmds/etcd_snapshot.go

@@ -122,7 +122,7 @@ func NewEtcdSnapshotSubcommands(delete, list, prune, save func(ctx *cli.Context)
 			Action:          prune,
 			Flags: append(EtcdSnapshotFlags, &cli.IntFlag{
 				Name:        "snapshot-retention",
-				Usage:       "(db) Number of snapshots to retain",
+				Usage:       "(db) Number of snapshots to retain. Default: 5",
 				Destination: &ServerConfig.EtcdSnapshotRetention,
 				Value:       defaultSnapshotRentention,
 			}),

pkg/cli/cmds/server.go

@@ -252,7 +252,7 @@ func NewServerCommand(action func(*cli.Context) error) cli.Command {
 			},
 			&cli.IntFlag{
 				Name:        "etcd-snapshot-retention",
-				Usage:       "(db) Number of snapshots to retain",
+				Usage:       "(db) Number of snapshots to retain Default: 5",
 				Destination: &ServerConfig.EtcdSnapshotRetention,
 				Value:       defaultSnapshotRentention,
 			},

pkg/etcd/etcd.go

@@ -978,6 +978,14 @@ func (e *ETCD) PruneSnapshots(ctx context.Context) error {
 		return errors.Wrap(err, "failed to get the snapshot dir")
 	}
 
+	if e.config.EtcdS3 {
+		if e.initS3IfNil(ctx); err != nil {
+			return err
+		}
+
+		return e.s3.snapshotRetention(ctx)
+	}
+
 	return snapshotRetention(e.config.EtcdSnapshotRetention, snapshotDir)
 }