feat: Allow helm templater plugin to get custom prefixes from kustomize

Author: liam-mackie

pkg/plugins/optional/helm/v2alpha/scaffolds/edit_kustomize.go

@@ -109,7 +109,8 @@ func (s *editKustomizeScaffolder) Scaffold() error {
 			slog.Warn("failed to remove stale generic ServiceMonitor", "path", staleSM, "error", rmErr)
 		}
 	}
-	chartConverter := kustomize.NewChartConverter(resources, s.config.GetProjectName(), s.outputDir)
+	namePrefix := resources.EstimatePrefix(s.config.GetProjectName())
+	chartConverter := kustomize.NewChartConverter(resources, s.config.GetProjectName(), namePrefix, s.outputDir)
 	deploymentConfig := chartConverter.ExtractDeploymentConfig()
 
 	// Create scaffold for standard Helm chart files
@@ -119,7 +120,8 @@ func (s *editKustomizeScaffolder) Scaffold() error {
 	chartFiles := []machinery.Builder{
 		&github.HelmChartCI{},                        // GitHub Actions workflow for chart testing
 		&templates.HelmChart{OutputDir: s.outputDir}, // Chart.yaml metadata
-		&templates.HelmValuesBasic{ // values.yaml with dynamic config
+		&templates.HelmValuesBasic{
+			// values.yaml with dynamic config
 			HasWebhooks:      hasWebhooks,
 			HasMetrics:       hasMetrics,
 			DeploymentConfig: deploymentConfig,
@@ -134,7 +136,20 @@ func (s *editKustomizeScaffolder) Scaffold() error {
 	// provide one via kustomize (../prometheus). This avoids duplicate objects
 	// with the same name within the Helm chart.
 	if !hasPrometheus {
-		chartFiles = append(chartFiles, &charttemplates.ServiceMonitor{OutputDir: s.outputDir})
+		// Find the metrics service name from parsed resources
+		metricsServiceName := namePrefix + "-controller-manager-metrics-service"
+		for _, svc := range resources.Services {
+			if strings.Contains(svc.GetName(), "metrics-service") {
+				metricsServiceName = svc.GetName()
+				break
+			}
+		}
+
+		chartFiles = append(chartFiles, &charttemplates.ServiceMonitor{
+			OutputDir:   s.outputDir,
+			NamePrefix:  namePrefix,
+			ServiceName: metricsServiceName,
+		})
 	}
 
 	// Generate template files from kustomize output

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/chart_converter.go

@@ -37,9 +37,9 @@ type ChartConverter struct {
 }
 
 // NewChartConverter creates a new chart converter with all necessary components
-func NewChartConverter(resources *ParsedResources, projectName, outputDir string) *ChartConverter {
+func NewChartConverter(resources *ParsedResources, projectName, namePrefix, outputDir string) *ChartConverter {
 	organizer := NewResourceOrganizer(resources)
-	templater := NewHelmTemplater(projectName)
+	templater := NewHelmTemplater(projectName, namePrefix)
 	writer := NewChartWriter(templater, outputDir)
 
 	return &ChartConverter{

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/chart_converter_test.go

@@ -55,7 +55,7 @@ var _ = Describe("ChartConverter", func() {
 		fs = machinery.Filesystem{FS: afero.NewMemMapFs()}
 
 		// Create converter
-		converter = NewChartConverter(resources, "test-project", "dist")
+		converter = NewChartConverter(resources, "test-project", "test-project", "dist")
 	})
 
 	Context("NewChartConverter", func() {

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/chart_writer.go

@@ -44,7 +44,8 @@ func NewChartWriter(templater *HelmTemplater, outputDir string) *ChartWriter {
 }
 
 // WriteResourceGroup writes a group of resources to a Helm template file
-func (w *ChartWriter) WriteResourceGroup(fs machinery.Filesystem, groupName string,
+func (w *ChartWriter) WriteResourceGroup(
+	fs machinery.Filesystem, groupName string,
 	resources []*unstructured.Unstructured,
 ) error {
 	// Special handling for namespace - write as single file
@@ -73,7 +74,8 @@ func (w *ChartWriter) writeNamespaceFile(fs machinery.Filesystem, namespace *uns
 }
 
 // writeGroupDirectory writes resources as files in a group-specific directory
-func (w *ChartWriter) writeGroupDirectory(fs machinery.Filesystem, groupName string,
+func (w *ChartWriter) writeGroupDirectory(
+	fs machinery.Filesystem, groupName string,
 	resources []*unstructured.Unstructured,
 ) error {
 	var finalContent bytes.Buffer
@@ -112,7 +114,8 @@ func (w *ChartWriter) shouldSplitFiles(groupName string) bool {
 }
 
 // writeSplitFiles writes each resource in the group to its own file
-func (w *ChartWriter) writeSplitFiles(fs machinery.Filesystem, groupName string,
+func (w *ChartWriter) writeSplitFiles(
+	fs machinery.Filesystem, groupName string,
 	resources []*unstructured.Unstructured,
 ) error {
 	// Create the group directory
@@ -142,7 +145,7 @@ func (w *ChartWriter) generateFileName(resource *unstructured.Unstructured, inde
 	// Try to use the resource name if available
 	if name := resource.GetName(); name != "" {
 		// Remove project prefix from the filename for cleaner file names
-		projectPrefix := w.templater.projectName + "-"
+		projectPrefix := w.templater.namePrefix + "-"
 		fileName := name
 		if strings.HasPrefix(name, projectPrefix) {
 			fileName = strings.TrimPrefix(name, projectPrefix)

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/helm_templater.go

@@ -48,12 +48,14 @@ const (
 // HelmTemplater handles converting YAML content to Helm templates
 type HelmTemplater struct {
 	projectName string
+	namePrefix  string
 }
 
 // NewHelmTemplater creates a new Helm templater
-func NewHelmTemplater(projectName string) *HelmTemplater {
+func NewHelmTemplater(projectName string, namePrefix string) *HelmTemplater {
 	return &HelmTemplater{
 		projectName: projectName,
+		namePrefix:  namePrefix,
 	}
 }
 
@@ -184,11 +186,16 @@ func (t *HelmTemplater) templateServiceMonitorNames(yamlContent string, resource
 
 	// Normalize suffix by stripping the project prefix if present
 	suffix := origName
-	prefix := t.projectName + "-"
+	prefix := t.namePrefix + "-"
 	if strings.HasPrefix(origName, prefix) {
 		suffix = strings.TrimPrefix(origName, prefix)
 	}
 
+	// If the prefix is not the project name, we should keep the original name intact
+	if prefix != t.projectName+"-" {
+		return yamlContent
+	}
+
 	// Only template if the intended target follows the conventional suffix
 	// This keeps any custom user-provided names intact
 	// For default scaffolding, suffix is typically "controller-manager-metrics-monitor"

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/helm_templater_test.go

@@ -28,6 +28,7 @@ var _ = Describe("HelmTemplater", func() {
 	BeforeEach(func() {
 		templater = &HelmTemplater{
 			projectName: "test-project",
+			namePrefix:  "test-project",
 		}
 	})
 
@@ -225,6 +226,43 @@ metadata:
 			Expect(result).To(ContainSubstring("{{- end }}"))
 		})
 
+		Describe("should generate ServiceMonitor name correctly", func() {
+			var serviceMonitorResource *unstructured.Unstructured
+			var content string
+
+			BeforeEach(func() {
+				serviceMonitorResource = &unstructured.Unstructured{}
+				serviceMonitorResource.SetAPIVersion("monitoring.coreos.com/v1")
+				serviceMonitorResource.SetKind("ServiceMonitor")
+				serviceMonitorResource.SetName("test-project-controller-manager-metrics-monitor")
+
+				// Test content must end with a newline
+				// If not, the `name` regex in the ServiceMonitor replacement will never match
+				content = `apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: test-project-controller-manager-metrics-monitor
+`
+			})
+
+			It("should use chart.name template when namePrefix and project name are the same", func() {
+				result := templater.ApplyHelmSubstitutions(content, serviceMonitorResource)
+				// If the namePrefix and default chart name match, should use chart.name template
+				Expect(result).To(ContainSubstring("{{ include \"chart.name\" . }}"),
+					"Should use chart.name template when namePrefix and project name match")
+			})
+			It("should preserve the original name when the namePrefix and project name differ", func() {
+				templaterDiff := &HelmTemplater{
+					projectName: "project-with-a-long-name",
+					namePrefix:  "test-project",
+				}
+				result := templaterDiff.ApplyHelmSubstitutions(content, serviceMonitorResource)
+				// If the namePrefix and default chart name differ, should use namePrefix variable
+				Expect(result).ToNot(ContainSubstring("{{ include \"chart.name\" . }}"),
+					"Should not use chart.name template when namePrefix and project name differ")
+			})
+		})
+
 		It("should add metrics conditional for metrics services", func() {
 			serviceResource := &unstructured.Unstructured{}
 			serviceResource.SetAPIVersion("v1")

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/parser.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strings"
 
 	"gopkg.in/yaml.v3"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -151,3 +152,26 @@ func (p *Parser) categorizeResource(obj *unstructured.Unstructured, resources *P
 		resources.Other = append(resources.Other, obj)
 	}
 }
+
+func (pr *ParsedResources) EstimatePrefix(projectName string) string {
+	prefix := projectName
+	if pr.Deployment != nil {
+		if name := pr.Deployment.GetName(); name != "" {
+			deploymentPrefix, found := strings.CutSuffix(name, "-controller-manager")
+			if found {
+				prefix = deploymentPrefix
+			}
+		}
+	}
+	// Double check that the prefix is also the prefix for the service names
+	for _, svc := range pr.Services {
+		if name := svc.GetName(); name != "" {
+			if !strings.HasPrefix(name, prefix) {
+				// If not, fallback to just project name
+				prefix = projectName
+				break
+			}
+		}
+	}
+	return prefix
+}

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/kustomize/parser_test.go

@@ -283,4 +283,42 @@ spec:
 			Expect(issuer.GetKind()).To(Equal("Issuer"))
 		})
 	})
+
+	Context("with custom prefix", func() {
+		BeforeEach(func() {
+			yamlContent := `---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: ln-controller-manager
+  namespace: long-name-test-system
+spec:
+  replicas: 1
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: ln-controller-manager-metrics-service
+  namespace: long-name-test-system
+spec:
+  ports:
+  - name: https
+    port: 8443
+    targetPort: 8443
+  selector:
+    control-plane: ln-controller-manager
+`
+			err := os.WriteFile(tempFile, []byte(yamlContent), 0o600)
+			Expect(err).NotTo(HaveOccurred())
+
+			parser = NewParser(tempFile)
+		})
+
+		It("should use the correct prefix", func() {
+			resources, err := parser.Parse()
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(resources.EstimatePrefix("long-name")).To(Equal("ln"))
+		})
+	})
 })

pkg/plugins/optional/helm/v2alpha/scaffolds/internal/templates/chart-templates/servicemonitor.go

@@ -29,7 +29,12 @@ var _ machinery.Template = &ServiceMonitor{}
 // ServiceMonitor scaffolds a ServiceMonitor for Prometheus monitoring in the Helm chart
 type ServiceMonitor struct {
 	machinery.TemplateMixin
-	machinery.ProjectNameMixin
+
+	// Prefix
+	NamePrefix string
+
+	// ServiceName is the full name of the metrics service, derived from Kustomize
+	ServiceName string
 
 	// OutputDir specifies the output directory for the chart
 	OutputDir string
@@ -59,7 +64,7 @@ metadata:
   labels:
     {{ "{{- include \"chart.labels\" . | nindent 4 }}" }}
     control-plane: controller-manager
-  name: {{ .ProjectName }}-controller-manager-metrics-monitor
+  name: {{ .NamePrefix }}-controller-manager-metrics-monitor
   namespace: {{ "{{ .Release.Namespace }}" }}
 spec:
   endpoints:
@@ -69,7 +74,7 @@ spec:
       bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
       tlsConfig:
         {{ "{{- if .Values.certManager.enable }}" }}
-        serverName: {{ .ProjectName }}-controller-manager-metrics-service.{{ "{{ .Release.Namespace }}" }}.svc
+        serverName: {{ .ServiceName }}.{{ "{{ .Release.Namespace }}" }}.svc
         # Apply secure TLS configuration with cert-manager
         insecureSkipVerify: false
         ca: