ScaleIO Volume Plugin - volume attribute updates

This commit introduces the following updates and fixes:
- Enable scaleIO volume multip-mapping based on accessMode
- No longer uses "default" as default values for storagepool & protection domain
- validates capacity when capacity is zero
- Better naming for PV and volume
- make mount ro when accessModes contains ROM

pkg/volume/scaleio/sio_util.go

@@ -68,11 +68,13 @@ var (
 	nsSep       = "%"
 	sdcRootPath = "/opt/emc/scaleio/sdc/bin"
 
-	secretNotFoundErr       = errors.New("secret not found")
-	configMapNotFoundErr    = errors.New("configMap not found")
-	gatewayNotProvidedErr   = errors.New("gateway not provided")
-	secretRefNotProvidedErr = errors.New("secret ref not provided")
-	systemNotProvidedErr    = errors.New("secret not provided")
+	secretNotFoundErr              = errors.New("secret not found")
+	configMapNotFoundErr           = errors.New("configMap not found")
+	gatewayNotProvidedErr          = errors.New("ScaleIO gateway not provided")
+	secretRefNotProvidedErr        = errors.New("secret ref not provided")
+	systemNotProvidedErr           = errors.New("ScaleIO system not provided")
+	storagePoolNotProvidedErr      = errors.New("ScaleIO storage pool not provided")
+	protectionDomainNotProvidedErr = errors.New("ScaleIO protection domain not provided")
 )
 
 // mapScaleIOVolumeSource maps attributes from a ScaleIOVolumeSource to config
@@ -107,6 +109,12 @@ func validateConfigs(config map[string]string) error {
 	if config[confKey.system] == "" {
 		return systemNotProvidedErr
 	}
+	if config[confKey.storagePool] == "" {
+		return storagePoolNotProvidedErr
+	}
+	if config[confKey.protectionDomain] == "" {
+		return protectionDomainNotProvidedErr
+	}
 
 	return nil
 }
@@ -119,8 +127,6 @@ func applyConfigDefaults(config map[string]string) {
 		b = false
 	}
 	config[confKey.sslEnabled] = strconv.FormatBool(b)
-	config[confKey.protectionDomain] = defaultString(config[confKey.protectionDomain], "default")
-	config[confKey.storagePool] = defaultString(config[confKey.storagePool], "default")
 	config[confKey.storageMode] = defaultString(config[confKey.storageMode], "ThinProvisioned")
 	config[confKey.fsType] = defaultString(config[confKey.fsType], "xfs")
 	b, err = strconv.ParseBool(config[confKey.readOnly])