Use constants for gateway names to avoid bugs caused by spelling. (#10355)

cmd/gateway/azure/gateway-azure.go

@@ -73,7 +73,6 @@ const (
 	azureBlockSize             = 100 * humanize.MiByte
 	azureS3MinPartSize         = 5 * humanize.MiByte
 	metadataObjectNameTemplate = minio.GatewayMinioSysTmp + "multipart/v1/%s.%x/azure.json"
-	azureBackend               = "azure"
 	azureMarkerPrefix          = "{minio}"
 	metadataPartNamePrefix     = minio.GatewayMinioSysTmp + "multipart/v1/%s.%x"
 	maxPartsCount              = 10000
@@ -113,7 +112,7 @@ EXAMPLES:
 `
 
 	minio.RegisterGatewayCommand(cli.Command{
-		Name:               azureBackend,
+		Name:               minio.AzureBackendGateway,
 		Usage:              "Microsoft Azure Blob Storage",
 		Action:             azureGatewayMain,
 		CustomHelpTemplate: azureGatewayTemplate,
@@ -170,7 +169,7 @@ type Azure struct {
 
 // Name implements Gateway interface.
 func (g *Azure) Name() string {
-	return azureBackend
+	return minio.AzureBackendGateway
 }
 
 // NewGatewayLayer initializes azure blob storage client and returns AzureObjects.

cmd/gateway/gcs/gateway-gcs.go

@@ -91,8 +91,6 @@ const (
 
 	// Project ID key in credentials.json
 	gcsProjectIDKey = "project_id"
-
-	gcsBackend = "gcs"
 )
 
 func init() {
@@ -132,7 +130,7 @@ EXAMPLES:
 `
 
 	minio.RegisterGatewayCommand(cli.Command{
-		Name:               gcsBackend,
+		Name:               minio.GCSBackendGateway,
 		Usage:              "Google Cloud Storage",
 		Action:             gcsGatewayMain,
 		CustomHelpTemplate: gcsGatewayTemplate,
@@ -145,13 +143,13 @@ func gcsGatewayMain(ctx *cli.Context) {
 	projectID := ctx.Args().First()
 	if projectID == "" && os.Getenv("GOOGLE_APPLICATION_CREDENTIALS") == "" {
 		logger.LogIf(minio.GlobalContext, errGCSProjectIDNotFound, logger.Application)
-		cli.ShowCommandHelpAndExit(ctx, "gcs", 1)
+		cli.ShowCommandHelpAndExit(ctx, minio.GCSBackendGateway, 1)
 	}
 	if projectID != "" && !isValidGCSProjectIDFormat(projectID) {
 		reqInfo := (&logger.ReqInfo{}).AppendTags("projectID", ctx.Args().First())
 		contxt := logger.SetReqInfo(minio.GlobalContext, reqInfo)
 		logger.LogIf(contxt, errGCSInvalidProjectID, logger.Application)
-		cli.ShowCommandHelpAndExit(ctx, "gcs", 1)
+		cli.ShowCommandHelpAndExit(ctx, minio.GCSBackendGateway, 1)
 	}
 
 	minio.StartGateway(ctx, &GCS{projectID})
@@ -164,7 +162,7 @@ type GCS struct {
 
 // Name returns the name of gcs ObjectLayer.
 func (g *GCS) Name() string {
-	return gcsBackend
+	return minio.GCSBackendGateway
 }
 
 // NewGatewayLayer returns gcs ObjectLayer.

cmd/gateway/hdfs/gateway-hdfs.go

@@ -47,8 +47,6 @@ import (
 )
 
 const (
-	hdfsBackend = "hdfs"
-
 	hdfsSeparator = minio.SlashSeparator
 )
 
@@ -84,7 +82,7 @@ EXAMPLES:
 `
 
 	minio.RegisterGatewayCommand(cli.Command{
-		Name:               hdfsBackend,
+		Name:               minio.HDFSBackendGateway,
 		Usage:              "Hadoop Distributed File System (HDFS)",
 		Action:             hdfsGatewayMain,
 		CustomHelpTemplate: hdfsGatewayTemplate,
@@ -96,7 +94,7 @@ EXAMPLES:
 func hdfsGatewayMain(ctx *cli.Context) {
 	// Validate gateway arguments.
 	if ctx.Args().First() == "help" {
-		cli.ShowCommandHelpAndExit(ctx, hdfsBackend, 1)
+		cli.ShowCommandHelpAndExit(ctx, minio.HDFSBackendGateway, 1)
 	}
 
 	minio.StartGateway(ctx, &HDFS{args: ctx.Args()})
@@ -109,7 +107,7 @@ type HDFS struct {
 
 // Name implements Gateway interface.
 func (g *HDFS) Name() string {
-	return hdfsBackend
+	return minio.HDFSBackendGateway
 }
 
 func getKerberosClient() (*krb.Client, error) {

cmd/gateway/nas/gateway-nas.go

@@ -24,10 +24,6 @@ import (
 	"github.com/minio/minio/pkg/auth"
 )
 
-const (
-	nasBackend = "nas"
-)
-
 func init() {
 	const nasGatewayTemplate = `NAME:
   {{.HelpName}} - {{.Usage}}
@@ -61,7 +57,7 @@ EXAMPLES:
 `
 
 	minio.RegisterGatewayCommand(cli.Command{
-		Name:               nasBackend,
+		Name:               minio.NASBackendGateway,
 		Usage:              "Network-attached storage (NAS)",
 		Action:             nasGatewayMain,
 		CustomHelpTemplate: nasGatewayTemplate,
@@ -73,7 +69,7 @@ EXAMPLES:
 func nasGatewayMain(ctx *cli.Context) {
 	// Validate gateway arguments.
 	if !ctx.Args().Present() || ctx.Args().First() == "help" {
-		cli.ShowCommandHelpAndExit(ctx, nasBackend, 1)
+		cli.ShowCommandHelpAndExit(ctx, minio.NASBackendGateway, 1)
 	}
 
 	minio.StartGateway(ctx, &NAS{ctx.Args().First()})
@@ -86,7 +82,7 @@ type NAS struct {
 
 // Name implements Gateway interface.
 func (g *NAS) Name() string {
-	return nasBackend
+	return minio.NASBackendGateway
 }
 
 // NewGatewayLayer returns nas gatewaylayer.

cmd/gateway/s3/gateway-s3.go

@@ -40,10 +40,6 @@ import (
 	"github.com/minio/minio/pkg/bucket/policy"
 )
 
-const (
-	s3Backend = "s3"
-)
-
 func init() {
 	const s3GatewayTemplate = `NAME:
   {{.HelpName}} - {{.Usage}}
@@ -76,7 +72,7 @@ EXAMPLES:
 `
 
 	minio.RegisterGatewayCommand(cli.Command{
-		Name:               s3Backend,
+		Name:               minio.S3BackendGateway,
 		Usage:              "Amazon Simple Storage Service (S3)",
 		Action:             s3GatewayMain,
 		CustomHelpTemplate: s3GatewayTemplate,
@@ -109,7 +105,7 @@ type S3 struct {
 
 // Name implements Gateway interface.
 func (g *S3) Name() string {
-	return s3Backend
+	return minio.S3BackendGateway
 }
 
 const letterBytes = "abcdefghijklmnopqrstuvwxyz01234569"