Allow tsi to be enabled via config option

tsdb/config.go

@@ -51,7 +51,7 @@ const (
 type Config struct {
 	Dir    string `toml:"dir"`
 	Engine string `toml:"-"`
-	Index  string `toml:"-"`
+	Index  string `toml:"index-version"`
 
 	// General WAL configuration options
 	WALDir string `toml:"wal-dir"`

tsdb/index.go

@@ -76,12 +76,12 @@ func RegisteredIndexes() []string {
 // If the path does not exist then the DefaultFormat is used.
 func NewIndex(id uint64, path string, options EngineOptions) (Index, error) {
 	// Create a new index.
-	if _, err := os.Stat(path); os.IsNotExist(err) {
+	if _, err := os.Stat(path); os.IsNotExist(err) && options.Config.Index != "inmem" {
 		return newIndexFuncs[options.IndexVersion](id, path, options), nil
 	}
 
 	// Use default format.
-	format := DefaultIndex
+	format := options.Config.Index
 
 	// Lookup index by format.
 	fn := newIndexFuncs[format]

tsdb/index/tsi1/index.go

@@ -14,6 +14,12 @@ import (
 	"github.com/influxdata/influxdb/tsdb"
 )
 
+func init() {
+	tsdb.RegisterIndex("tsi1", func(id uint64, path string, opt tsdb.EngineOptions) tsdb.Index {
+		return &Index{Path: path}
+	})
+}
+
 // File extensions.
 const (
 	LogFileExt   = ".tsi.log"

tsdb/shard.go

@@ -245,6 +245,11 @@ func (s *Shard) Open() error {
 
 		// Initialize underlying index.
 		ipath := filepath.Join(s.path, "index")
+		// Create directory.
+		if err := os.MkdirAll(ipath, 0700); err != nil {
+			return err
+		}
+
 		idx, err := NewIndex(s.id, ipath, s.options)
 		if err != nil {
 			return err