Merge pull request #1546 from ConnorJC3/snow-mount

Grab snow device path via last character rather than trimming

pkg/driver/node_linux.go

@@ -101,7 +101,11 @@ func (d *nodeService) findDevicePath(devicePath, volumeID, partition string) (st
 
 	if util.IsSBE(d.metadata.GetRegion()) {
 		klog.V(5).InfoS("[Debug] Falling back to snow volume lookup", "devicePath", devicePath)
-		canonicalDevicePath = "/dev/vd" + strings.TrimPrefix(devicePath, "/dev/xvdb")
+		// Snow completely ignores the requested device path and mounts volumes starting at /dev/vda .. /dev/vdb .. etc
+		// Morph the device path to the snow form by chopping off the last letter and prefixing with /dev/vd
+		// VMs on snow devices are currently limited to 10 block devices each - if that ever exceeds 26 this will need
+		// to be adapted
+		canonicalDevicePath = "/dev/vd" + devicePath[len(devicePath)-1:]
 	}
 
 	if canonicalDevicePath == "" {

pkg/driver/node_linux_test.go

@@ -32,7 +32,7 @@ import (
 )
 
 func TestFindDevicePath(t *testing.T) {
-	devicePath := "/dev/xvdba"
+	devicePath := "/dev/xvdaa"
 	nvmeDevicePath := "/dev/nvme1n1"
 	snowDevicePath := "/dev/vda"
 	volumeID := "vol-test"
@@ -120,6 +120,20 @@ func TestFindDevicePath(t *testing.T) {
 			},
 			expectDevicePath: snowDevicePath,
 		},
+		{
+			name:       "success: non-standard snow device path",
+			devicePath: "/dev/sda",
+			volumeID:   volumeID,
+			partition:  "",
+			expectMock: func(mockMounter MockMounter, mockDeviceIdentifier MockDeviceIdentifier) {
+				gomock.InOrder(
+					mockMounter.EXPECT().PathExists(gomock.Eq("/dev/sda")).Return(false, nil),
+
+					mockDeviceIdentifier.EXPECT().Lstat(gomock.Eq(nvmeName)).Return(nil, os.ErrNotExist),
+				)
+			},
+			expectDevicePath: snowDevicePath,
+		},
 	}
 	// The partition variant of each case should be the same except the partition
 	// is expected to be appended to devicePath