torusctl: support specifying ring type by init command

cmd/torusctl/init.go

@@ -16,11 +16,12 @@ import (
 )
 
 var (
-	blockSize    uint64
-	blockSizeStr string
-	blockSpec    string
-	noMakeRing   bool
-	metaView     bool
+	blockSize     uint64
+	blockSizeStr  string
+	blockSpec     string
+	metaView      bool
+	initRingType  string
+	initRepFactor int
 )
 
 var initCommand = &cobra.Command{
@@ -33,8 +34,9 @@ var initCommand = &cobra.Command{
 func init() {
 	initCommand.Flags().StringVarP(&blockSizeStr, "block-size", "", "512KiB", "size of all data blocks in this storage cluster")
 	initCommand.Flags().StringVarP(&blockSpec, "block-spec", "", "crc", "default replication/error correction applied to blocks in this storage cluster")
-	initCommand.Flags().BoolVar(&noMakeRing, "no-ring", false, "do not create the default ring as part of init")
 	initCommand.Flags().BoolVar(&metaView, "view", false, "view metadata configured in this storage cluster")
+	initCommand.Flags().StringVar(&initRingType, "type", "ketama", "type of ring to create (empty, single, mod or ketama)")
+	initCommand.Flags().IntVarP(&initRepFactor, "replication", "r", 2, "number of replicas")
 }
 
 func initPreRun(cmd *cobra.Command, args []string) {
@@ -62,15 +64,34 @@ func initAction(cmd *cobra.Command, args []string) {
 		die("error parsing block-spec: %v", err)
 	}
 
-	cfg := flagconfig.BuildConfigFromFlags()
-	ringType := ring.Ketama
-	if noMakeRing {
+	var ringType torus.RingType
+	switch initRingType {
+	case "empty":
+		if initRepFactor != 0 {
+			die(`invalid number of replicas for empty ring. Use "--replication=0"`)
+		}
 		ringType = ring.Empty
+	case "single":
+		die(`Currently single ring type is not supported by init. Use torusctl ring manual-change after adding one node."`)
+		/*
+			if initRepFactor != 1 {
+				die(`invalid number of replicas for single ring. Use "--replication=1"`)
+			}
+			iRingType = ring.Single
+		*/
+	case "mod":
+		ringType = ring.Mod
+	case "ketama":
+		ringType = ring.Ketama
+	default:
+		die(`invalid ring type %s (try "empty", "mod", "single" or "ketama")`, initRingType)
 	}
-	err = torus.InitMDS("etcd", cfg, md, ringType)
+	cfg := flagconfig.BuildConfigFromFlags()
+	err = torus.InitMDS("etcd", cfg, md, ringType, initRepFactor)
 	if err != nil {
 		die("error writing metadata: %v", err)
 	}
+
 }
 
 func viewMetadata() {

cmd/torusd/main.go

@@ -157,7 +157,7 @@ func runServer(cmd *cobra.Command, args []string) {
 		err = torus.InitMDS("etcd", cfg, torus.GlobalMetadata{
 			BlockSize:        512 * 1024,
 			DefaultBlockSpec: blockset.MustParseBlockLayerSpec("crc,base"),
-		}, ring.Ketama)
+		}, ring.Ketama, 2)
 		if err != nil {
 			if err == torus.ErrExists {
 				fmt.Println("debug-init: Already exists")

metadata.go

@@ -99,7 +99,7 @@ func CreateMetadataService(name string, cfg Config) (MetadataService, error) {
 }
 
 // InitMDSFunc is the signature of a function which preformats a metadata service.
-type InitMDSFunc func(cfg Config, gmd GlobalMetadata, ringType RingType) error
+type InitMDSFunc func(cfg Config, gmd GlobalMetadata, ringType RingType, repFactor int) error
 
 var initMDSFuncs map[string]InitMDSFunc
 
@@ -118,9 +118,9 @@ func RegisterMetadataInit(name string, newFunc InitMDSFunc) {
 }
 
 // InitMDS calls the specific init function provided by a metadata package.
-func InitMDS(name string, cfg Config, gmd GlobalMetadata, ringType RingType) error {
+func InitMDS(name string, cfg Config, gmd GlobalMetadata, ringType RingType, repFactor int) error {
 	clog.Debugf("running InitMDS for service type: %s", name)
-	return initMDSFuncs[name](cfg, gmd, ringType)
+	return initMDSFuncs[name](cfg, gmd, ringType, repFactor)
 }
 
 type WipeMDSFunc func(cfg Config) error

metadata/etcd/global_funcs.go

@@ -11,15 +11,15 @@ import (
 	"golang.org/x/net/context"
 )
 
-func initEtcdMetadata(cfg torus.Config, gmd torus.GlobalMetadata, ringType torus.RingType) error {
+func initEtcdMetadata(cfg torus.Config, gmd torus.GlobalMetadata, ringType torus.RingType, repFactor int) error {
 	gmdbytes, err := json.Marshal(gmd)
 	if err != nil {
 		return err
 	}
 	emptyRing, err := ring.CreateRing(&models.Ring{
 		Type:              uint32(ringType),
 		Version:           1,
-		ReplicationFactor: 2,
+		ReplicationFactor: uint32(repFactor),
 	})
 	if err != nil {
 		return err