modify /etc/cloud/cloud.cfg for Debian

pkg/distros/debian.go

@@ -2,6 +2,7 @@ package distros
 
 import (
 	"bufio"
+	"bytes"
 	"errors"
 	"fmt"
 	"net/http"
@@ -71,10 +72,55 @@ func (mgr *DebianTemplateManager) DownloadTemplate(version, codename string) (pa
 	return mgr.DownloadTemplateGeneric(filename, url)
 }
 
+func (mgr *DebianTemplateManager) replaceFailsafeMirrorsInCloudCfg(handle *guestfs.Guestfs) error {
+	// In Debian 12 (bookworm), /etc/cloud/cloud.cfg has the following snippet:
+	//
+	// system_info:
+	//   package_mirrors:
+	//     - arches: [default]
+	//       failsafe:
+	//         primary: https://deb.debian.org/debian
+	//         security: https://deb.debian.org/debian-security
+	//
+	// Since we can't override the system_info settings, we need to overwrite this file.
+	filePaths := []string{"/etc/cloud/cloud.cfg"}
+	// To be safe, we check other config files under /etc/cloud/cloud.cfg.d as well.
+	extraFilePaths, err := handle.Glob_expand("/etc/cloud/cloud.cfg.d/*.cfg", nil)
+	if err != nil {
+		return fmt.Errorf("Could not expand glob /etc/cloud/cloud.cfg.d/*.cfg: %w", err)
+	}
+	filePaths = append(filePaths, extraFilePaths...)
+	debMirrorUrlRegex := regexp.MustCompile(`https?://deb\.debian\.org`)
+	replacement := []byte("http://" + mgr.cfg.MirrorHost)
+	for _, filePath := range filePaths {
+		mgr.logger.Debug().Str("file", filePath).Msg("Checking for deb.debian.org URLs")
+		content, err := handle.Read_file(filePath)
+		if err != nil {
+			return fmt.Errorf("Could not read %s: %w", filePath, err)
+		}
+		newContent := debMirrorUrlRegex.ReplaceAll(content, replacement)
+		if bytes.Equal(content, newContent) {
+			continue
+		}
+		mgr.logger.Debug().Str("file", filePath).Msg("Replacing deb.debian.org URLs")
+		err = handle.Write(filePath, newContent)
+		if err != nil {
+			return fmt.Errorf("Could not write to %s: %w", filePath, err)
+		}
+	}
+	return nil
+}
+
 func (mgr *DebianTemplateManager) CommandToUpdatePackageCache() []string {
 	return debianCommandToUpdatePackageCache()
 }
 
 func (mgr *DebianTemplateManager) PerformDistroSpecificModifications(handle *guestfs.Guestfs) error {
-	return mgr.replaceDebianMirrorUrls(handle)
+	if err := mgr.replaceFailsafeMirrorsInCloudCfg(handle); err != nil {
+		return err
+	}
+	if err := mgr.replaceDebianMirrorUrls(handle); err != nil {
+		return err
+	}
+	return nil
 }