Change VM customization to use a YAML output file instead of XML.

As part of the virt-v2v migration, we inspect the OS type and disk paths.
Until now, this has been done with the XML output file. Due to the change
to YAML format, this process needs to be adapted as well.
Since we cannot use external libraries in the virt-v2v directory,
it was implemented using bufio.

Signed-off-by: Bella Khizgiyaev <bkhizgiy@redhat.com>

virt-v2v/cold/entrypoint.go

@@ -82,18 +82,8 @@ func main() {
 	}
 }
 
-func getVmDiskPaths(domain *OvaVmconfig) []string {
-	var resp []string
-	for _, disk := range domain.Devices.Disks {
-		if disk.Source.File != "" {
-			resp = append(resp, disk.Source.File)
-		}
-	}
-	return resp
-}
-
-func customizeVM(source string, xmlFilePath string) error {
-	domain, err := GetDomainFromXml(xmlFilePath)
+func customizeVM(source string, yamlFilePath string) error {
+	vmConfig, err := GetVmConfigYaml(yamlFilePath)
 	if err != nil {
 		fmt.Printf("Error mapping xml to domain: %v\n", err)
 
@@ -102,7 +92,7 @@ func customizeVM(source string, xmlFilePath string) error {
 	}
 
 	// Get operating system.
-	operatingSystem := domain.Metadata.LibOsInfo.V2VOS.ID
+	operatingSystem := vmConfig.OSInfo
 	if operatingSystem == "" {
 		fmt.Printf("Warning: no operating system found")
 
@@ -112,15 +102,13 @@ func customizeVM(source string, xmlFilePath string) error {
 		fmt.Printf("Operating System ID: %s\n", operatingSystem)
 	}
 
-	// Get domain disks.
-	disks := getVmDiskPaths(domain)
-	if len(disks) == 0 {
+	if len(vmConfig.DiskPaths) == 0 {
 		fmt.Printf("Warning: no V2V domain disks found")
 
 		// No customization when no disks found.
 		return nil
 	} else {
-		fmt.Printf("V2V domain disks: %v\n", disks)
+		fmt.Printf("V2V domain disks: %v\n", vmConfig.DiskPaths)
 	}
 
 	// Customization for vSphere source.
@@ -129,7 +117,7 @@ func customizeVM(source string, xmlFilePath string) error {
 		if strings.Contains(operatingSystem, "win") {
 			t := EmbedTool{filesystem: &scriptFS}
 
-			err = CustomizeWindows(disks, DIR, &t)
+			err = CustomizeWindows(vmConfig.DiskPaths, DIR, &t)
 			if err != nil {
 				fmt.Println("Error customizing disk image:", err)
 				return err
@@ -140,7 +128,7 @@ func customizeVM(source string, xmlFilePath string) error {
 		if !strings.Contains(operatingSystem, "win") {
 			t := EmbedTool{filesystem: &scriptFS}
 
-			err = CustomizeLinux(CustomizeDomainExec, disks, DIR, &t)
+			err = CustomizeLinux(CustomizeDomainExec, vmConfig.DiskPaths, DIR, &t)
 			if err != nil {
 				fmt.Println("Error customizing disk image:", err)
 				return err

virt-v2v/cold/yaml-reader.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+type VmConfig struct {
+	OSInfo    string
+	DiskPaths []string
+}
+
+// ReadYAMLFile reads the YAML file and extracts the HostDisk paths and osinfo label.
+func GetVmConfigYaml(filePath string) (*VmConfig, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("error opening YAML file: %w", err)
+	}
+	defer file.Close()
+
+	config := &VmConfig{}
+	scanner := bufio.NewScanner(file)
+	var inLabels, inVolumes bool
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		if strings.HasPrefix(line, "labels:") {
+			inLabels = true
+			continue
+		}
+
+		if inLabels {
+			if strings.HasPrefix(line, "libguestfs.org/osinfo:") {
+				config.OSInfo = strings.TrimSpace(strings.TrimPrefix(line, "libguestfs.org/osinfo:"))
+			}
+			if !strings.HasPrefix(line, "libguestfs.org/") {
+				inLabels = false
+			}
+		}
+
+		if strings.Contains(line, "volumes:") {
+			inVolumes = true
+			continue
+		}
+		if inVolumes {
+			if strings.Contains(line, "hostDisk:") {
+				scanner.Scan()
+				pathLine := strings.TrimSpace(scanner.Text())
+				if strings.HasPrefix(pathLine, "path:") {
+					pathValue := strings.TrimSpace(strings.TrimPrefix(pathLine, "path:"))
+					if pathValue != "" {
+						config.DiskPaths = append(config.DiskPaths, pathValue)
+					}
+				}
+			}
+			if strings.Contains(line, "- name:") {
+				inVolumes = false
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error reading YAML file: %w", err)
+	}
+
+	return config, nil
+}