use different names for each disk. closes #14

4 files changed, 40 insertions, 2 deletions

diff --git a/libvirt/disk_def.go b/libvirt/disk_def.go
index 41e8d5f2..88a9f76a 100644
--- a/libvirt/disk_def.go
+++ b/libvirt/disk_def.go
@@ -37,8 +37,6 @@ func newDefDisk() defDisk {
 	disk.Type = "volume"
 	disk.Device = "disk"
 	disk.Format.Type = "qcow2"
-
-	disk.Target.Dev = "sda"
 	disk.Target.Bus = "virtio"
 
 	return disk
diff --git a/libvirt/resource_libvirt_domain.go b/libvirt/resource_libvirt_domain.go
index 8752a574..7d26e1b9 100644
--- a/libvirt/resource_libvirt_domain.go
+++ b/libvirt/resource_libvirt_domain.go
@@ -65,6 +65,7 @@ func resourceLibvirtDomainCreate(d *schema.ResourceData, meta interface{}) error
 	for i := 0; i < disksCount; i++ {
 		prefix := fmt.Sprintf("disk.%d", i)
 		disk := newDefDisk()
+		disk.Target.Dev = fmt.Sprintf("sd%s", DiskLetterForIndex(i))
 
 		volumeKey := d.Get(prefix + ".volume_id").(string)
 		diskVolume, err := virConn.LookupStorageVolByKey(volumeKey)
diff --git a/libvirt/utils.go b/libvirt/utils.go
new file mode 100644
index 00000000..335003a9
--- /dev/null
+++ b/libvirt/utils.go
@@ -0,0 +1,21 @@
+package libvirt
+
+import (
+	"fmt"
+)
+
+var diskLetters []rune = []rune("abcdefghijklmnopqrstuvwxyz")
+
+func DiskLetterForIndex(i int) string {
+
+	q := i / len(diskLetters)
+	r := i % len(diskLetters)
+	letter := diskLetters[r]
+
+	if q == 0 {
+		return fmt.Sprintf("%c", letter)
+	}
+
+	return fmt.Sprintf("%s%c", DiskLetterForIndex(q - 1), letter)
+}
+
diff --git a/libvirt/utils_test.go b/libvirt/utils_test.go
new file mode 100644
index 00000000..6e945fac
--- /dev/null
+++ b/libvirt/utils_test.go
@@ -0,0 +1,18 @@
+package libvirt
+
+import (
+	"testing"
+)
+
+func TestDiskLetterForIndex(t *testing.T) {
+
+	diskNumbers := []int{0, 1, 2, 3, 4, 16, 24, 25, 26, 30, 300}
+	names := []string{"a", "b", "c", "d", "e", "q", "y", "z", "aa", "ae", "ko"}
+
+	for i, diskNumber := range(diskNumbers) {
+		ret := DiskLetterForIndex(diskNumber)
+		if ret != names[i] {
+			t.Errorf("Expected %s, got %s for disk %d", names[i], ret, diskNumber)
+		}
+	}
+}