Fix backup handling of images and systemd files.

This commit fixes several issues with the backup:

- podman inspect needs the full image path, not just the basename of
  it. In order to get the image that is currently used we read it from
  the systemd service config files.

- computing the list of systemd files ourselves is error prone and
  failed with instanciated services. Using `systemctl show -p` with the
  DropInPaths and FragmentPath is much safer.

Author: cbosdo

mgradm/cmd/backup/create/create.go

@@ -161,8 +161,13 @@ func gatherContainerImagesToBackup(skipImages bool) []string {
 
 	if !skipImages {
 		for _, service := range utils.UyuniServices {
-			if present, err := podman.IsImagePresent(service.Image.Name); err == nil && len(present) > 0 {
-				images = append(images, service.Image.Name)
+			serviceName, skip := findService(service.Name)
+			if skip {
+				continue
+			}
+			image := podman.GetServiceImage(serviceName)
+			if image != "" {
+				images = append(images, image)
 			}
 		}
 	}

mgradm/cmd/backup/create/systemd_utils.go

@@ -10,6 +10,7 @@ import (
 	"io"
 	"os"
 	"path"
+	"strings"
 
 	"github.com/rs/zerolog/log"
 	backup "github.com/uyuni-project/uyuni-tools/mgradm/cmd/backup/shared"
@@ -76,20 +77,19 @@ func gatherSystemdItems() []string {
 			continue
 		}
 
-		result = append(result, podman.GetServicePath(serviceName))
-		// For single mandatory replica following returns 0 so loop is skipped
-		for i := 0; i < systemd.CurrentReplicaCount(service.Name); i++ {
-			result = append(result, podman.GetServicePath(fmt.Sprintf("%s%d", serviceName, i)))
-		}
-		serviceConfDir := podman.GetServiceConfFolder(serviceName)
-		serviceFiles, err := os.ReadDir(serviceConfDir)
+		servicePath, err := systemd.GetServiceProperty(serviceName, podman.FragmentPath)
 		if err != nil {
-			log.Debug().Msgf("Service configuration directory %s not found, skipping", serviceConfDir)
-			continue
+			log.Error().Err(err).Msgf(L("failed to get the path to the %s service file"), serviceName)
+		} else {
+			result = append(result, servicePath)
 		}
-		result = append(result, serviceConfDir)
-		for _, entry := range serviceFiles {
-			result = append(result, path.Join(serviceConfDir, entry.Name()))
+
+		// Get the drop in files
+		dropIns, err := systemd.GetServiceProperty(serviceName, podman.DropInPaths)
+		if err != nil {
+			log.Error().Err(err).Msgf(L("failed to get the path to the %s service configuration files"), serviceName)
+		} else {
+			result = append(result, strings.Split(dropIns, " ")...)
 		}
 	}
 	return result

shared/podman/images.go

@@ -12,6 +12,7 @@ import (
 	"net/url"
 	"os"
 	"path"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -354,18 +355,21 @@ func DeleteImage(name string, dryRun bool) error {
 	return nil
 }
 
+var newRunner = utils.NewRunner
+
 // ExportImage saves a podman image based on its name to a specified directory.
 // outputDir option expects already existing directory.
 // If dryRun is set to true, nothing will be done, only messages logged to explain what would happen.
 func ExportImage(name string, outputDir string, dryRun bool) error {
 	exists := imageExists(name)
 	if exists {
-		saveCommand := []string{"podman", "image", "save", "--quiet", "-o", path.Join(outputDir, name+".tar"), name}
+		baseName, _, _ := strings.Cut(filepath.Base(name), ":")
+		saveCommand := []string{"podman", "image", "save", "--quiet", "-o", path.Join(outputDir, baseName+".tar"), name}
 		if dryRun {
 			log.Info().Msgf(L("Would run %s"), strings.Join(saveCommand, " "))
 		} else {
 			log.Info().Msgf(L("Run %s"), strings.Join(saveCommand, " "))
-			err := utils.RunCmd(saveCommand[0], saveCommand[1:]...)
+			_, err := newRunner(saveCommand[0], saveCommand[1:]...).Exec()
 			if err != nil {
 				return utils.Errorf(err, L("Failed to export image %s"), name)
 			}
@@ -385,7 +389,7 @@ func RestoreImage(imageFile string, dryRun bool) error {
 		log.Info().Msgf(L("Would run %s"), strings.Join(restoreCommand, " "))
 	} else {
 		log.Info().Msgf(L("Run %s"), strings.Join(restoreCommand, " "))
-		err := utils.RunCmd(restoreCommand[0], restoreCommand[1:]...)
+		_, err := newRunner(restoreCommand[0], restoreCommand[1:]...).Exec()
 		if err != nil {
 			return utils.Errorf(err, L("Failed to restore image %s"), imageFile)
 		}

shared/podman/interfaces.go

@@ -1,9 +1,17 @@
-// SPDX-FileCopyrightText: 2024 SUSE LLC
+// SPDX-FileCopyrightText: 2025 SUSE LLC
 //
 // SPDX-License-Identifier: Apache-2.0
 
 package podman
 
+const (
+	// FragmentPath is a systemd property containing the path of the service file.
+	FragmentPath = "FragmentPath"
+
+	// DropInPaths is a systemd property containing the paths of the service configuration file separated by a space.
+	DropInPaths = "DropInPaths"
+)
+
 // Systemd is an interface providing systemd operations.
 type Systemd interface {
 
@@ -65,4 +73,7 @@ type Systemd interface {
 
 	// GetServicesFromSystemdFiles return the uyuni enabled services as string list.
 	GetServicesFromSystemdFiles(systemdFileList string) []string
+
+	// GetServiceProperty returns the value of a systemd service property.
+	GetServiceProperty(service string, property string) (string, error)
 }

shared/podman/systemd.go

@@ -73,6 +73,18 @@ func GetServicePath(name string) string {
 	return path.Join(servicesPath, name+".service")
 }
 
+func (s SystemdImpl) GetServiceProperty(service string, property string) (string, error) {
+	serviceName := service
+	if strings.HasSuffix(service, "@") {
+		serviceName = service + "0"
+	}
+	out, err := newRunner("systemctl", "show", "-p", property, serviceName).Exec()
+	if err != nil {
+		return "", utils.Errorf(err, L("Failed to get the %[1]s property from %[2]s service"), property, service)
+	}
+	return strings.TrimPrefix(strings.TrimSpace(string(out)), property+"="), nil
+}
+
 // GetServiceConfFolder return the conf folder for systemd services.
 func GetServiceConfFolder(name string) string {
 	return path.Join(servicesPath, name+".service.d")

shared/podman/systemd_test.go

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2024 SUSE LLC
+// SPDX-FileCopyrightText: 2025 SUSE LLC
 //
 // SPDX-License-Identifier: Apache-2.0
 
@@ -91,3 +91,5 @@ Environment="PODMAN_EXTRA_ARGS="
 	actual = testutils.ReadFile(t, path.Join(serviceConfDir, "custom.conf"))
 	testutils.AssertEquals(t, "invalid custom.conf file", customFile, actual)
 }
+
+// TODO Add tests for GetServiceProperty

shared/podman/utils.go

@@ -146,10 +146,10 @@ func GetServiceImage(service string) string {
 		return ""
 	}
 
-	imageFinder := regexp.MustCompile(`UYUNI_IMAGE=(.*)`)
+	imageFinder := regexp.MustCompile(`UYUNI.*_IMAGE=(.*)`)
 	matches := imageFinder.FindStringSubmatch(string(out))
 	if len(matches) < 2 {
-		log.Warn().Msgf(L("no UYUNI_IMAGE defined in %s systemd service"), service)
+		log.Warn().Msgf(L("no UYUNI.*_IMAGE defined in %s systemd service"), service)
 		return ""
 	}
 	return matches[1]