Always append shard path in diags

This code is clearer -- simply append an empty path if the shard is not
local.

Fixes issue #2430

CHANGELOG.md

@@ -10,6 +10,7 @@
 - [#2426](https://github.com/influxdb/influxdb/pull/2426): Fix race condition around listener address in openTSDB server.
 - [#2426](https://github.com/influxdb/influxdb/pull/2426): Fix race condition around listener address in Graphite server.
 - [#2429](https://github.com/influxdb/influxdb/pull/2429): Ensure no field value is null.
+- [#2431](https://github.com/influxdb/influxdb/pull/2431): Always append shard path in diags. Thanks @marcosnils
 
 ### Features
 - [#2410](https://github.com/influxdb/influxdb/pull/2410) Allow configuration of Raft timers

cmd/influxd/server_integration_test.go

@@ -1464,6 +1464,11 @@ func TestSingleServerDiags(t *testing.T) {
 	nodes := createCombinedNodeCluster(t, testName, dir, 1, config)
 	defer nodes.Close()
 
+	// Ensure some data shards also exist.
+	createDatabase(t, testName, nodes, "mydb")
+	createRetentionPolicy(t, testName, nodes, "mydb", "myrp", len(nodes))
+	write(t, nodes[0], `{"database" : "mydb", "retentionPolicy" : "myrp", "points": [{"name": "cpu", "fields": {"value": 100}}]}`)
+
 	time.Sleep(1 * time.Second)
 }
 

server.go

@@ -3339,21 +3339,19 @@ func (s *Server) DiagnosticsAsRows() []*influxql.Row {
 	// Shards
 	shardsRow := &influxql.Row{Columns: []string{}}
 	shardsRow.Name = "shards_diag"
-	shardsRow.Columns = append(shardsRow.Columns, "time", "id", "dataNodes", "index")
+	shardsRow.Columns = append(shardsRow.Columns, "time", "id", "dataNodes", "index", "path")
 	shardsRow.Tags = tags
 	for _, sh := range s.shards {
 		var nodes []string
 		for _, n := range sh.DataNodeIDs {
 			nodes = append(nodes, strconv.FormatUint(n, 10))
 		}
-		shardsRow.Values = append(shardsRow.Values, []interface{}{now, strconv.FormatUint(sh.ID, 10),
-			strings.Join(nodes, ","), strconv.FormatUint(sh.Index(), 10)})
-
-		// Shard may not be local to this node.
+		var path string
 		if sh.store != nil {
-			shardsRow.Columns = append(shardsRow.Columns, "path")
-			shardsRow.Values[0] = append(shardsRow.Values[0], sh.store.Path())
+			path = sh.store.Path()
 		}
+		shardsRow.Values = append(shardsRow.Values, []interface{}{now, strconv.FormatUint(sh.ID, 10),
+			strings.Join(nodes, ","), strconv.FormatUint(sh.Index(), 10), path})
 	}
 
 	return []*influxql.Row{