feat(build, imageSpec): support template werf variables (%image%, %project%) for labels (#6724)

Signed-off-by: Yaroslav Pershin <62902094+iapershin@users.noreply.github.com>

Author: iapershin

Diff for: docs/pages_en/usage/build/images.md

@@ -520,6 +520,26 @@ imageSpec:
       PATH: "${PATH}:/app/bin"
 ```
 
+### Working with labels
+
+When working with labels, you can use templating. The following variables are currently available:
+
+- %image% – the name of the image
+- %project% – the name of the project
+
+```yaml
+project: test  
+configVersion: 1  
+---  
+image: backend  
+from: alpine:3.21  
+imageSpec:  
+  config:  
+    labels:   
+      frontend-version: "1.2.3"  
+      project-%project%: "%image%-image"  
+```
+
 ## Linking images
 
 ### Inheritance and importing files

Diff for: docs/pages_ru/usage/build/images.md

@@ -519,6 +519,26 @@ imageSpec:
       PATH: "${PATH}:/app/bin"
 ```
 
+### Работа с лейблами образов
+
+При работе с лейблами вы можете использовать шаблонизацию. На текущий момент доступны следующие переменные:
+
+ - `%image%` - имя образа
+ - `%project%` - имя проекта
+
+```yaml
+project: test
+configVersion: 1
+---
+image: backend
+from: alpine:3.21
+imageSpec:
+  config:
+    labels: 
+      frontend-version: "1.2.3"
+      project-%project%: "%image%-image"
+```
+
 ## Взаимодействие между образами
 
 ### Наследование и импортирование файлов

Diff for: pkg/build/stage/image_spec.go

@@ -1,8 +1,10 @@
 package stage
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"html/template"
 	"regexp"
 	"sort"
 	"strings"
@@ -17,6 +19,9 @@ import (
 )
 
 const (
+	labelTemplateImage           = "image"
+	labelTemplateProject         = "project"
+	labelTemplateDelimiter       = "%"
 	werfLabelsGlobalWarning      = "Removal of the werf labels requires explicit use of the clearWerfLabels directive. Some labels are purely informational, while others are essential for cleanup operations."
 	werfLabelsHostCleanupWarning = "Removal of the %s label will affect host auto cleanup. Proper work of auto cleanup is not guaranteed."
 )
@@ -78,9 +83,7 @@ func (s *ImageSpecStage) PrepareImage(ctx context.Context, _ Conveyor, _ contain
 			newConfig.ClearEntrypoint = newConfig.ClearEntrypoint || s.imageSpec.ClearEntrypoint
 		}
 
-		serviceLabels := s.stageImage.Image.GetBuildServiceLabels()
-		mergedLabels := util.MergeMaps(s.imageSpec.Labels, serviceLabels)
-		resultLabels, err := modifyLabels(ctx, mergedLabels, s.imageSpec.Labels, s.imageSpec.RemoveLabels, s.imageSpec.ClearWerfLabels)
+		resultLabels, err := s.modifyLabels(ctx, imageInfo.Labels, s.imageSpec.Labels, s.imageSpec.RemoveLabels, s.imageSpec.ClearWerfLabels)
 		if err != nil {
 			return fmt.Errorf("unable to modify labels: %s", err)
 		}
@@ -147,11 +150,30 @@ func (s *ImageSpecStage) GetDependencies(_ context.Context, _ Conveyor, _ contai
 	return util.Sha256Hash(args...), nil
 }
 
-func modifyLabels(ctx context.Context, labels, addLabels map[string]string, removeLabels []string, clearWerfLabels bool) (map[string]string, error) {
+func (s *ImageSpecStage) modifyLabels(ctx context.Context, labels, addLabels map[string]string, removeLabels []string, clearWerfLabels bool) (map[string]string, error) {
 	if labels == nil {
 		labels = make(map[string]string)
 	}
 
+	serviceLabels := s.stageImage.Image.GetBuildServiceLabels()
+	labels = util.MergeMaps(labels, serviceLabels)
+
+	processedAddLabels := make(map[string]string, len(addLabels))
+	data := labelsTemplateData{
+		Project: s.projectName,
+		Image:   s.imageName,
+	}
+
+	for key, value := range addLabels {
+		newKey, newValue, err := replaceLabelTemplate(key, value, data)
+		if err != nil {
+			return nil, err
+		}
+		processedAddLabels[newKey] = newValue
+	}
+
+	labels = util.MergeMaps(labels, processedAddLabels)
+
 	exactMatches := make(map[string]struct{})
 	var regexPatterns []*regexp.Regexp
 
@@ -206,11 +228,43 @@ func modifyLabels(ctx context.Context, labels, addLabels map[string]string, remo
 		global_warnings.GlobalWarningLn(ctx, fmt.Sprintf(werfLabelsHostCleanupWarning, strings.Join(cleanupWarnKeys, "','")))
 	}
 
-	for key, value := range addLabels {
-		labels[key] = value
+	return labels, nil
+}
+
+type labelsTemplateData struct {
+	Project string
+	Image   string
+}
+
+func replaceLabelTemplate(k, v string, data labelsTemplateData) (string, string, error) {
+	funcMap := template.FuncMap{
+		labelTemplateProject: func() string { return data.Project },
+		labelTemplateImage:   func() string { return data.Image },
 	}
 
-	return labels, nil
+	keyTmpl := template.New("key").Delims(labelTemplateDelimiter, labelTemplateDelimiter).Funcs(funcMap)
+	valueTmpl := template.New("value").Delims(labelTemplateDelimiter, labelTemplateDelimiter).Funcs(funcMap)
+
+	parsedKeyTmpl, err := keyTmpl.Parse(k)
+	if err != nil {
+		return "", "", err
+	}
+
+	parsedValueTmpl, err := valueTmpl.Parse(v)
+	if err != nil {
+		return "", "", err
+	}
+
+	var keyBuf, valueBuf bytes.Buffer
+
+	if err := parsedKeyTmpl.Execute(&keyBuf, data); err != nil {
+		return "", "", err
+	}
+
+	if err := parsedValueTmpl.Execute(&valueBuf, data); err != nil {
+		return "", "", err
+	}
+	return keyBuf.String(), valueBuf.String(), nil
 }
 
 func modifyEnv(env, removeKeys []string, addKeysMap map[string]string) ([]string, error) {

Diff for: pkg/build/stage/image_spec_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/werf/werf/v2/pkg/config"
+	"github.com/werf/werf/v2/pkg/container_backend"
 )
 
 func TestEnvExpander(t *testing.T) {
@@ -97,6 +98,7 @@ func TestModifyLabels(t *testing.T) {
 			clearWerfLabels: false,
 			expectedLabels: map[string]string{
 				"werf": "should-stay",
+				"stub": "true",
 			},
 		},
 		{
@@ -109,6 +111,7 @@ func TestModifyLabels(t *testing.T) {
 			clearWerfLabels: false,
 			expectedLabels: map[string]string{
 				"test-label": "bar",
+				"stub":       "true",
 			},
 		},
 		{
@@ -124,6 +127,7 @@ func TestModifyLabels(t *testing.T) {
 			expectedLabels: map[string]string{
 				"test-label": "bar",
 				"not-werf":   "keep",
+				"stub":       "true",
 			},
 		},
 		{
@@ -139,6 +143,7 @@ func TestModifyLabels(t *testing.T) {
 				"test-label": "bar",
 				"new":        "value",
 				"other":      "123",
+				"stub":       "true",
 			},
 		},
 		{
@@ -152,12 +157,15 @@ func TestModifyLabels(t *testing.T) {
 			removeLabels:    []string{"remove"},
 			clearWerfLabels: true,
 			addLabels: map[string]string{
-				"new": "added",
+				"new":                  "added",
+				"project-%project%-id": "image-%image%-name",
 			},
 			expectedLabels: map[string]string{
-				"test-label": "bar",
-				"keep":       "me",
-				"new":        "added",
+				"test-label":              "bar",
+				"keep":                    "me",
+				"new":                     "added",
+				"project-TEST-PROJECT-id": "image-TEST-IMAGE-name",
+				"stub":                    "true",
 			},
 		},
 	}
@@ -169,13 +177,31 @@ func TestModifyLabels(t *testing.T) {
 				labelsCopy[k] = v
 			}
 
-			modifiedLabels, err := modifyLabels(ctx, labelsCopy, tt.addLabels, tt.removeLabels, tt.clearWerfLabels)
+			s := ImageSpecStage{
+				BaseStage: &BaseStage{
+					projectName: "TEST-PROJECT",
+					imageName:   "TEST-IMAGE",
+					stageImage: &StageImage{
+						Image: NewLegacyImageStub(),
+					},
+				},
+			}
+
+			modifiedLabels, err := s.modifyLabels(ctx, labelsCopy, tt.addLabels, tt.removeLabels, tt.clearWerfLabels)
 			assert.NoError(t, err)
 			assert.Equal(t, tt.expectedLabels, modifiedLabels)
 		})
 	}
 }
 
+type MockImage struct {
+	Labels map[string]string
+}
+
+func (i *MockImage) Build(_ context.Context, _ container_backend.BuildOptions) error {
+	return nil
+}
+
 func TestModifyVolumes(t *testing.T) {
 	tests := []struct {
 		name           string

Diff for: pkg/build/stage/stubs.go

@@ -30,6 +30,12 @@ func (img *LegacyImageStub) Container() container_backend.LegacyContainer {
 	return img._Container
 }
 
+func (img *LegacyImageStub) GetBuildServiceLabels() map[string]string {
+	return map[string]string{
+		"stub": "true",
+	}
+}
+
 type LegacyContainerStub struct {
 	container_backend.LegacyContainer