backport: fix virt-v2v disk name generation

Makefile

@@ -84,7 +84,7 @@ all: test forklift-controller
 
 # Run tests
 test: generate fmt vet manifests validation-test
-	go test -coverprofile=cover.out ./pkg/... ./cmd/...
+	go test -coverprofile=cover.out ./pkg/... ./cmd/... ./virt-v2v/cold/...
 
 # Experimental e2e target
 e2e-sanity: e2e-sanity-ovirt e2e-sanity-vsphere

virt-v2v/cold/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 load(
     "@io_bazel_rules_docker//container:container.bzl",
     "container_image",
@@ -478,3 +478,9 @@ rpmtree(
     ],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "cold_test",
+    srcs = ["cold_test.go"],
+    embed = [":cold_lib"],
+)

virt-v2v/cold/cold_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestGenName(t *testing.T) {
+	cases := []struct {
+		diskNum  int
+		expected string
+	}{
+		{1, "a"},
+		{26, "z"},
+		{27, "aa"},
+		{28, "ab"},
+		{52, "az"},
+		{53, "ba"},
+		{55, "bc"},
+		{702, "zz"},
+		{754, "abz"},
+	}
+
+	for _, c := range cases {
+		got := genName(c.diskNum)
+		if got != c.expected {
+			t.Errorf("genName(%d) = %s; want %s", c.diskNum, got, c.expected)
+		}
+	}
+}

virt-v2v/cold/entrypoint.go

@@ -142,11 +142,15 @@ func genName(diskNum int) string {
 		return ""
 	}
 
-	letters := []int32("abcdefghijklmnopqrstuvwxyz")
+	letters := "abcdefghijklmnopqrstuvwxyz"
 	index := (diskNum - 1) % len(letters)
-	cycels := (diskNum - 1) % len(letters)
+	cycles := (diskNum - 1) / len(letters)
 
-	return genName(cycels) + string(letters[index])
+	if cycles == 0 {
+		return string(letters[index])
+	} else {
+		return genName(cycles) + string(letters[index])
+	}
 }
 
 func LinkDisks(diskKind string, num int) (err error) {