diff --git a/cmd/devenv/generate.go b/cmd/devenv/generate.go
index 2324141..c71d50b 100644
--- a/cmd/devenv/generate.go
+++ b/cmd/devenv/generate.go
@@ -31,6 +31,7 @@ var (
 	configDir string // Input directory for developer configs
 	dryRun    bool
 	allDevs   bool
+	noCleanup bool
 )
 
 var generateCmd = &cobra.Command{
@@ -75,6 +76,7 @@ func init() {
 	generateCmd.Flags().StringVar(&configDir, "config-dir", "./developers", "Directory containing developer configuration files")
 	generateCmd.Flags().BoolVar(&dryRun, "dry-run", false, "Show what would be generated without creating files")
 	generateCmd.Flags().BoolVar(&allDevs, "all-developers", false, "Generate manifests for all developers")
+	generateCmd.Flags().BoolVar(&noCleanup, "no-cleanup", false, "Preserve files from previous runs instead of removing unplanned outputs")
 
 }
 
@@ -266,12 +268,11 @@ func generateSingleDeveloper(developerName string) {
 }
 
 func generateSystemManifests(cfg *config.BaseConfig, outputDir string) error {
-	// Create template renderer
-	renderer := templates.NewSystemRenderer(outputDir)
+	postRenderOpts := templates.NewPostRenderOptions(!noCleanup)
+	spec := templates.BuildSystemGenerationSpec(cfg, outputDir, postRenderOpts)
 
-	// Render all main templates
-	if err := renderer.RenderAll(cfg); err != nil {
-		return fmt.Errorf("failed to render templates: %w", err)
+	if err := generateManifests(spec); err != nil {
+		return err
 	}
 
 	fmt.Printf("🎉 Successfully generated system manifests\n")
@@ -281,12 +282,11 @@ func generateSystemManifests(cfg *config.BaseConfig, outputDir string) error {
 
 // generateDeveloperManifests creates Kubernetes manifests for a developer
 func generateDeveloperManifests(cfg *config.DevEnvConfig, outputDir string) error {
-	// Create template renderer
-	renderer := templates.NewDevRenderer(outputDir)
+	postRenderOpts := templates.NewPostRenderOptions(!noCleanup)
+	spec := templates.BuildDevGenerationSpec(cfg, outputDir, postRenderOpts)
 
-	// Render all main templates
-	if err := renderer.RenderAll(cfg); err != nil {
-		return fmt.Errorf("failed to render templates: %w", err)
+	if err := generateManifests(spec); err != nil {
+		return err
 	}
 
 	fmt.Printf("🎉 Successfully generated manifests for %s\n", cfg.Name)
@@ -294,6 +294,20 @@ func generateDeveloperManifests(cfg *config.DevEnvConfig, outputDir string) erro
 	return nil
 }
 
+func generateManifests[T config.BaseConfig | config.DevEnvConfig](spec templates.GenerationSpec[T]) error {
+	renderer := templates.NewRenderer(spec.OutputDir, spec.TemplateRoot, spec.Plan.TemplateNames, spec.Config)
+
+	if err := renderer.RenderAll(); err != nil {
+		return fmt.Errorf("failed to render templates: %w", err)
+	}
+
+	if err := templates.RunPostRender(spec.OutputDir, spec.Plan, spec.PostRenderOptions); err != nil {
+		return fmt.Errorf("failed to run post-render steps: %w", err)
+	}
+
+	return nil
+}
+
 // Helper function to print config summary
 func printConfigSummary(cfg *config.DevEnvConfig) {
 	fmt.Printf("\nConfiguration Summary:\n")
diff --git a/internal/config/types.go b/internal/config/types.go
index 7dbd14e..6bea234 100644
--- a/internal/config/types.go
+++ b/internal/config/types.go
@@ -222,6 +222,21 @@ func (c *DevEnvConfig) NodePort() int {
 	return c.SSHPort
 }
 
+// HasHTTPPort reports whether HTTP exposure is configured.
+func (c *DevEnvConfig) HasHTTPPort() bool {
+	return c != nil && c.HTTPPort != 0
+}
+
+// HasHostName reports whether a non-empty ingress hostname is configured.
+func (c *DevEnvConfig) HasHostName() bool {
+	return c != nil && strings.TrimSpace(c.HostName) != ""
+}
+
+// ShouldRenderIngress reports whether ingress can be safely rendered.
+func (c *DevEnvConfig) ShouldRenderIngress() bool {
+	return c.HasHTTPPort() && c.HasHostName()
+}
+
 // VolumeMounts returns the configured volume mount specifications.
 // Returns the slice of VolumeMount configurations for binding local directories
 // into the developer environment container.
diff --git a/internal/config/validation.go b/internal/config/validation.go
index cabf662..4d051f5 100644
--- a/internal/config/validation.go
+++ b/internal/config/validation.go
@@ -250,6 +250,22 @@ func ValidateDevEnvConfig(config *DevEnvConfig) error {
 		return fmt.Errorf("gpu must be >= 0")
 	}
 
+	if config.HasHTTPPort() && !config.HasHostName() {
+		return fmt.Errorf("hostName is required when httpPort is set")
+	}
+
+	if config.EnableAuth && config.SkipAuth {
+		return fmt.Errorf("enableAuth and skipAuth cannot both be true")
+	}
+
+	if config.EnableAuth && strings.TrimSpace(config.AuthURL) == "" {
+		return fmt.Errorf("authURL is required when enableAuth is true")
+	}
+
+	if config.EnableAuth && strings.TrimSpace(config.AuthSignIn) == "" {
+		return fmt.Errorf("authSignIn is required when enableAuth is true")
+	}
+
 	return nil
 }
 
diff --git a/internal/config/validation_test.go b/internal/config/validation_test.go
index 08d5a4f..1a5f428 100644
--- a/internal/config/validation_test.go
+++ b/internal/config/validation_test.go
@@ -347,3 +347,73 @@ func TestValidateDevEnvConfig_VolumeMountPaths(t *testing.T) {
 		assert.Contains(t, err.Error(), "ContainerPath")
 	})
 }
+
+func TestValidateDevEnvConfig_IngressDependencies(t *testing.T) {
+	newCfg := func() *DevEnvConfig {
+		return &DevEnvConfig{
+			Name: "alice",
+			BaseConfig: BaseConfig{
+				SSHPublicKey: "ssh-ed25519 AAAAB3NzaC1lZDI1NTE5AAAA user@host",
+			},
+		}
+	}
+
+	t.Run("requires hostName when httpPort is set", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.HTTPPort = 8080
+
+		err := ValidateDevEnvConfig(cfg)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "hostName is required when httpPort is set")
+	})
+
+	t.Run("allows httpPort with hostName", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.HTTPPort = 8080
+		cfg.HostName = "devenv.example.com"
+
+		require.NoError(t, ValidateDevEnvConfig(cfg))
+	})
+
+	t.Run("requires authURL when enableAuth is true", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.EnableAuth = true
+		cfg.AuthSignIn = "https://auth.example.com/start"
+
+		err := ValidateDevEnvConfig(cfg)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "authURL is required when enableAuth is true")
+	})
+
+	t.Run("requires authSignIn when enableAuth is true", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.EnableAuth = true
+		cfg.AuthURL = "https://auth.example.com/auth"
+
+		err := ValidateDevEnvConfig(cfg)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "authSignIn is required when enableAuth is true")
+	})
+
+	t.Run("allows enableAuth with auth URLs", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.EnableAuth = true
+		cfg.AuthURL = "https://auth.example.com/auth"
+		cfg.AuthSignIn = "https://auth.example.com/start"
+
+		require.NoError(t, ValidateDevEnvConfig(cfg))
+	})
+
+	t.Run("rejects enableAuth with skipAuth", func(t *testing.T) {
+		cfg := newCfg()
+		cfg.EnableAuth = true
+		cfg.SkipAuth = true
+		cfg.AuthURL = "https://auth.example.com/auth"
+		cfg.AuthSignIn = "https://auth.example.com/start"
+
+		err := ValidateDevEnvConfig(cfg)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "enableAuth and skipAuth cannot both be true")
+	})
+
+}
diff --git a/internal/templates/generation_spec.go b/internal/templates/generation_spec.go
new file mode 100644
index 0000000..3513a2f
--- /dev/null
+++ b/internal/templates/generation_spec.go
@@ -0,0 +1,31 @@
+package templates
+
+import "github.com/nauticalab/devenv-engine/internal/config"
+
+type GenerationSpec[T config.BaseConfig | config.DevEnvConfig] struct {
+	Config            *T
+	Plan              RenderPlan
+	OutputDir         string
+	TemplateRoot      string
+	PostRenderOptions PostRenderOptions
+}
+
+func BuildDevGenerationSpec(cfg *config.DevEnvConfig, outputDir string, postRenderOpts PostRenderOptions) GenerationSpec[config.DevEnvConfig] {
+	return GenerationSpec[config.DevEnvConfig]{
+		Config:            cfg,
+		Plan:              BuildDevRenderPlan(cfg),
+		OutputDir:         outputDir,
+		TemplateRoot:      "template_files/dev",
+		PostRenderOptions: postRenderOpts,
+	}
+}
+
+func BuildSystemGenerationSpec(cfg *config.BaseConfig, outputDir string, postRenderOpts PostRenderOptions) GenerationSpec[config.BaseConfig] {
+	return GenerationSpec[config.BaseConfig]{
+		Config:            cfg,
+		Plan:              BuildSystemRenderPlan(),
+		OutputDir:         outputDir,
+		TemplateRoot:      "template_files/system",
+		PostRenderOptions: postRenderOpts,
+	}
+}
diff --git a/internal/templates/plan.go b/internal/templates/plan.go
new file mode 100644
index 0000000..b426935
--- /dev/null
+++ b/internal/templates/plan.go
@@ -0,0 +1,41 @@
+package templates
+
+import "github.com/nauticalab/devenv-engine/internal/config"
+
+var devBaseTemplates = []string{"statefulset", "service", "env-vars", "startup-scripts"}
+
+var devOptionalTemplates = []string{"ingress"}
+
+var devManagedTemplates = append(append([]string{}, devBaseTemplates...), devOptionalTemplates...)
+
+var systemBaseTemplates = []string{"namespace"}
+
+var systemManagedTemplates = append([]string{}, systemBaseTemplates...)
+
+// RenderPlan defines template selection and ownership.
+type RenderPlan struct {
+	TemplateNames    []string
+	ManagedTemplates []string
+}
+
+// BuildDevRenderPlan computes the template set from config before rendering.
+func BuildDevRenderPlan(cfg *config.DevEnvConfig) RenderPlan {
+	templateNames := append([]string{}, devBaseTemplates...)
+
+	if cfg != nil && cfg.ShouldRenderIngress() {
+		templateNames = append(templateNames, "ingress")
+	}
+
+	return RenderPlan{
+		TemplateNames:    templateNames,
+		ManagedTemplates: append([]string{}, devManagedTemplates...),
+	}
+}
+
+// BuildSystemRenderPlan computes the template set for system-level manifests.
+func BuildSystemRenderPlan() RenderPlan {
+	return RenderPlan{
+		TemplateNames:    append([]string{}, systemBaseTemplates...),
+		ManagedTemplates: append([]string{}, systemManagedTemplates...),
+	}
+}
diff --git a/internal/templates/plan_test.go b/internal/templates/plan_test.go
new file mode 100644
index 0000000..9338c4c
--- /dev/null
+++ b/internal/templates/plan_test.go
@@ -0,0 +1,103 @@
+package templates
+
+import (
+	"testing"
+
+	"github.com/nauticalab/devenv-engine/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildDevRenderPlan(t *testing.T) {
+	t.Run("excludes ingress when HTTP port is unset", func(t *testing.T) {
+		cfg := &config.DevEnvConfig{}
+
+		plan := BuildDevRenderPlan(cfg)
+
+		assert.Equal(t, expectedDevTemplateNames(false), plan.TemplateNames)
+		assert.Equal(t, copyTemplateNames(devManagedTemplates), plan.ManagedTemplates)
+	})
+
+	t.Run("includes ingress when HTTP port is set", func(t *testing.T) {
+		cfg := &config.DevEnvConfig{HTTPPort: 8080, BaseConfig: config.BaseConfig{HostName: "devenv.example.com"}}
+
+		plan := BuildDevRenderPlan(cfg)
+
+		assert.Equal(t, expectedDevTemplateNames(true), plan.TemplateNames)
+		assert.Equal(t, copyTemplateNames(devManagedTemplates), plan.ManagedTemplates)
+	})
+
+	t.Run("excludes ingress when hostName is missing", func(t *testing.T) {
+		cfg := &config.DevEnvConfig{HTTPPort: 8080}
+
+		plan := BuildDevRenderPlan(cfg)
+
+		assert.Equal(t, expectedDevTemplateNames(false), plan.TemplateNames)
+		assert.Equal(t, copyTemplateNames(devManagedTemplates), plan.ManagedTemplates)
+	})
+}
+
+func TestBuildDevRenderPlan_Contract(t *testing.T) {
+	t.Run("http disabled", func(t *testing.T) {
+		plan := BuildDevRenderPlan(&config.DevEnvConfig{})
+		assert.Equal(t, []string{"statefulset", "service", "env-vars", "startup-scripts"}, plan.TemplateNames)
+		assert.Equal(t, []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"}, plan.ManagedTemplates)
+	})
+
+	t.Run("http enabled", func(t *testing.T) {
+		plan := BuildDevRenderPlan(&config.DevEnvConfig{HTTPPort: 8080, BaseConfig: config.BaseConfig{HostName: "devenv.example.com"}})
+		assert.Equal(t, []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"}, plan.TemplateNames)
+		assert.Equal(t, []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"}, plan.ManagedTemplates)
+	})
+}
+
+func TestBuildSystemRenderPlan(t *testing.T) {
+	plan := BuildSystemRenderPlan()
+
+	assert.Equal(t, copyTemplateNames(systemBaseTemplates), plan.TemplateNames)
+	assert.Equal(t, copyTemplateNames(systemManagedTemplates), plan.ManagedTemplates)
+}
+
+func TestBuildSystemRenderPlan_Contract(t *testing.T) {
+	plan := BuildSystemRenderPlan()
+	assert.Equal(t, []string{"namespace"}, plan.TemplateNames)
+	assert.Equal(t, []string{"namespace"}, plan.ManagedTemplates)
+}
+
+func TestRenderPlans_TargetTemplatesAreManaged(t *testing.T) {
+	t.Run("dev plan", func(t *testing.T) {
+		plan := BuildDevRenderPlan(&config.DevEnvConfig{HTTPPort: 8080, BaseConfig: config.BaseConfig{HostName: "devenv.example.com"}})
+		requireTargetSubsetOfManaged(t, plan.TemplateNames, plan.ManagedTemplates)
+	})
+
+	t.Run("system plan", func(t *testing.T) {
+		plan := BuildSystemRenderPlan()
+		requireTargetSubsetOfManaged(t, plan.TemplateNames, plan.ManagedTemplates)
+	})
+}
+
+func requireTargetSubsetOfManaged(t *testing.T, targetTemplates []string, managedTemplates []string) {
+	t.Helper()
+
+	managedSet := make(map[string]struct{}, len(managedTemplates))
+	for _, templateName := range managedTemplates {
+		managedSet[templateName] = struct{}{}
+	}
+
+	for _, templateName := range targetTemplates {
+		_, ok := managedSet[templateName]
+		require.Truef(t, ok, "target template %q is not managed", templateName)
+	}
+}
+
+func expectedDevTemplateNames(includeOptional bool) []string {
+	templateNames := copyTemplateNames(devBaseTemplates)
+	if includeOptional {
+		templateNames = append(templateNames, devOptionalTemplates...)
+	}
+	return templateNames
+}
+
+func copyTemplateNames(templateNames []string) []string {
+	return append([]string{}, templateNames...)
+}
diff --git a/internal/templates/post_render.go b/internal/templates/post_render.go
new file mode 100644
index 0000000..a691ae4
--- /dev/null
+++ b/internal/templates/post_render.go
@@ -0,0 +1,54 @@
+package templates
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type PostRenderOptions struct {
+	CleanupUnplanned bool
+}
+
+func NewPostRenderOptions(cleanupUnplanned bool) PostRenderOptions {
+	return PostRenderOptions{CleanupUnplanned: cleanupUnplanned}
+}
+
+// RunPostRender executes post-render steps for a completed render pass.
+func RunPostRender(outputDir string, plan RenderPlan, opts PostRenderOptions) error {
+	if opts.CleanupUnplanned {
+		if err := runPostRenderCleanup(outputDir, plan); err != nil {
+			return fmt.Errorf("cleanup unplanned outputs: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// runPostRenderCleanup removes managed outputs that are no longer planned.
+func runPostRenderCleanup(outputDir string, plan RenderPlan) error {
+	planned := make(map[string]struct{}, len(plan.TemplateNames))
+	for _, templateName := range plan.TemplateNames {
+		planned[templateName] = struct{}{}
+	}
+
+	for _, templateName := range plan.ManagedTemplates {
+		if _, ok := planned[templateName]; ok {
+			continue
+		}
+		if err := removeOutput(outputDir, templateName); err != nil {
+			return fmt.Errorf("failed to remove output for template %s: %w", templateName, err)
+		}
+	}
+
+	return nil
+}
+
+func removeOutput(outputDir string, templateName string) error {
+	outputPath := filepath.Join(outputDir, fmt.Sprintf("%s.yaml", templateName))
+	err := os.Remove(outputPath)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}
diff --git a/internal/templates/post_render_test.go b/internal/templates/post_render_test.go
new file mode 100644
index 0000000..2055240
--- /dev/null
+++ b/internal/templates/post_render_test.go
@@ -0,0 +1,81 @@
+package templates
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRunPostRender_RemovesUnplannedManagedOutputs(t *testing.T) {
+	tempDir := t.TempDir()
+	staleIngress := filepath.Join(tempDir, "ingress.yaml")
+	require.NoError(t, os.WriteFile(staleIngress, []byte("stale"), 0o644))
+
+	plan := RenderPlan{
+		TemplateNames:    []string{"statefulset", "service", "env-vars", "startup-scripts"},
+		ManagedTemplates: []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"},
+	}
+
+	err := RunPostRender(tempDir, plan, NewPostRenderOptions(true))
+	require.NoError(t, err)
+
+	_, err = os.Stat(staleIngress)
+	assert.ErrorIs(t, err, os.ErrNotExist)
+}
+
+func TestRunPostRender_PreservesPlannedOutputs(t *testing.T) {
+	tempDir := t.TempDir()
+	plannedIngress := filepath.Join(tempDir, "ingress.yaml")
+	require.NoError(t, os.WriteFile(plannedIngress, []byte("planned"), 0o644))
+
+	plan := RenderPlan{
+		TemplateNames:    []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"},
+		ManagedTemplates: []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"},
+	}
+
+	err := RunPostRender(tempDir, plan, NewPostRenderOptions(true))
+	require.NoError(t, err)
+
+	content, err := os.ReadFile(plannedIngress)
+	require.NoError(t, err)
+	assert.Equal(t, "planned", string(content))
+}
+
+func TestRunPostRender_IgnoresUnmanagedOutputs(t *testing.T) {
+	tempDir := t.TempDir()
+	unmanagedFile := filepath.Join(tempDir, "notes.yaml")
+	require.NoError(t, os.WriteFile(unmanagedFile, []byte("keep"), 0o644))
+
+	plan := RenderPlan{
+		TemplateNames:    []string{"namespace"},
+		ManagedTemplates: []string{"namespace"},
+	}
+
+	err := RunPostRender(tempDir, plan, NewPostRenderOptions(true))
+	require.NoError(t, err)
+
+	content, err := os.ReadFile(unmanagedFile)
+	require.NoError(t, err)
+	assert.Equal(t, "keep", string(content))
+}
+
+func TestRunPostRender_PreservesStaleOutputsWhenCleanupDisabled(t *testing.T) {
+	tempDir := t.TempDir()
+	staleIngress := filepath.Join(tempDir, "ingress.yaml")
+	require.NoError(t, os.WriteFile(staleIngress, []byte("stale"), 0o644))
+
+	plan := RenderPlan{
+		TemplateNames:    []string{"statefulset", "service", "env-vars", "startup-scripts"},
+		ManagedTemplates: []string{"statefulset", "service", "env-vars", "startup-scripts", "ingress"},
+	}
+
+	err := RunPostRender(tempDir, plan, PostRenderOptions{CleanupUnplanned: false})
+	require.NoError(t, err)
+
+	content, err := os.ReadFile(staleIngress)
+	require.NoError(t, err)
+	assert.Equal(t, "stale", string(content))
+}
diff --git a/internal/templates/renderer.go b/internal/templates/renderer.go
index 665b9be..b5cef60 100644
--- a/internal/templates/renderer.go
+++ b/internal/templates/renderer.go
@@ -12,11 +12,6 @@ import (
 	"github.com/nauticalab/devenv-engine/internal/config"
 )
 
-var devTemplatesToRender = []string{"statefulset", "service", "env-vars",
-	"startup-scripts", "ingress"}
-
-var systemTemplatesToRender = []string{"namespace"}
-
 // Embed all devTemplates and scripts at compile time
 //
 //go:embed template_files
@@ -27,22 +22,29 @@ type Renderer[T config.BaseConfig | config.DevEnvConfig] struct {
 	outputDir       string
 	templateRoot    string
 	targetTemplates []string
+	config          *T
 }
 
-// NewRenderer creates a new template renderer
-func NewDevRenderer(outputDir string) *Renderer[config.DevEnvConfig] {
-	return NewRendererWithFS[config.DevEnvConfig](outputDir, "template_files/dev", devTemplatesToRender)
+// NewDevRenderer is a convenience wrapper for dev-specific render tests and
+// direct callers. If the codebase standardizes on GenerationSpec + NewRenderer,
+// consider removing this wrapper.
+func NewDevRenderer(outputDir string, cfg *config.DevEnvConfig, templateNames []string) *Renderer[config.DevEnvConfig] {
+	return NewRenderer[config.DevEnvConfig](outputDir, "template_files/dev", templateNames, cfg)
 }
 
-func NewSystemRenderer(outputDir string) *Renderer[config.BaseConfig] {
-	return NewRendererWithFS[config.BaseConfig](outputDir, "template_files/system", systemTemplatesToRender)
+// NewSystemRenderer is a convenience wrapper for system-specific direct callers.
+// If the codebase standardizes on GenerationSpec + NewRenderer, consider
+// removing this wrapper.
+func NewSystemRenderer(outputDir string, cfg *config.BaseConfig, templateNames []string) *Renderer[config.BaseConfig] {
+	return NewRenderer[config.BaseConfig](outputDir, "template_files/system", templateNames, cfg)
 }
 
-func NewRendererWithFS[T config.BaseConfig | config.DevEnvConfig](outputDir string, templateRoot string, targetTemplates []string) *Renderer[T] {
+func NewRenderer[T config.BaseConfig | config.DevEnvConfig](outputDir string, templateRoot string, targetTemplates []string, cfg *T) *Renderer[T] {
 	return &Renderer[T]{
 		outputDir:       outputDir,
 		templateRoot:    templateRoot,
 		targetTemplates: targetTemplates,
+		config:          cfg,
 	}
 }
 
@@ -85,7 +87,7 @@ func templateFuncs(templateRoot string) template.FuncMap {
 	}
 }
 
-func (r *Renderer[T]) RenderTemplate(templateName string, config *T) error {
+func (r *Renderer[T]) RenderTemplate(templateName string) error {
 	// Get the template content from embedded files
 	templateContent, err := templates.ReadFile(filepath.Join(r.templateRoot, fmt.Sprintf("manifests/%s.tmpl", templateName)))
 	if err != nil {
@@ -115,7 +117,7 @@ func (r *Renderer[T]) RenderTemplate(templateName string, config *T) error {
 	defer outputFile.Close()
 
 	// Execute template with DevEnvConfig - simple and clean!
-	if err := tmpl.Execute(outputFile, config); err != nil {
+	if err := tmpl.Execute(outputFile, r.config); err != nil {
 		return fmt.Errorf("failed to render template %s: %w", templateName, err)
 	}
 
@@ -123,11 +125,12 @@ func (r *Renderer[T]) RenderTemplate(templateName string, config *T) error {
 	return nil
 }
 
-func (r *Renderer[T]) RenderAll(config *T) error {
+func (r *Renderer[T]) RenderAll() error {
 	for _, templateName := range r.targetTemplates {
-		if err := r.RenderTemplate(templateName, config); err != nil {
+		if err := r.RenderTemplate(templateName); err != nil {
 			return fmt.Errorf("failed to render template %s: %w", templateName, err)
 		}
 	}
+
 	return nil
 }
diff --git a/internal/templates/renderer_test.go b/internal/templates/renderer_test.go
index 2d9053c..3c1c055 100644
--- a/internal/templates/renderer_test.go
+++ b/internal/templates/renderer_test.go
@@ -24,9 +24,10 @@ func TestRenderTemplate(t *testing.T) {
 				"ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC7... testuser@example.com",
 				"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAI... testuser2@example.com",
 			},
-			UID:   2000,
-			Image: "ubuntu:22.04",
+			UID:       2000,
+			Image:     "ubuntu:22.04",
 			Namespace: "devenv-test",
+			HostName:  "devenv.example.com",
 			Packages: config.PackageConfig{
 				Python: []string{"numpy", "pandas"},
 				APT:    []string{"vim", "curl"},
@@ -66,10 +67,10 @@ func TestRenderTemplate(t *testing.T) {
 			tempDir := t.TempDir()
 
 			// Create renderer
-			renderer := NewDevRenderer(tempDir)
+			renderer := NewDevRenderer(tempDir, testConfig, BuildDevRenderPlan(testConfig).TemplateNames)
 
 			// Render template
-			err := renderer.RenderTemplate(templateName, testConfig)
+			err := renderer.RenderTemplate(templateName)
 			require.NoError(t, err, "Failed to render template %s", templateName)
 
 			// Read the generated output
@@ -105,36 +106,100 @@ func TestRenderTemplate(t *testing.T) {
 
 // TestRenderAll tests the RenderAll function that renders all templates
 func TestRenderAll(t *testing.T) {
-	// Create minimal test configuration
-	testConfig := &config.DevEnvConfig{
-		Name: "minimal",
-		BaseConfig: config.BaseConfig{
-			SSHPublicKey: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC7... minimal@example.com",
-			Namespace:   "devenv-test",
-		},
-		SSHPort: 30002,
-	}
+	t.Run("includes ingress when HTTP port is set", func(t *testing.T) {
+		testConfig := &config.DevEnvConfig{
+			Name: "minimal",
+			BaseConfig: config.BaseConfig{
+				SSHPublicKey: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC7... minimal@example.com",
+				Namespace:    "devenv-test",
+				HostName:     "devenv.example.com",
+			},
+			SSHPort:  30002,
+			HTTPPort: 8080,
+		}
+
+		tempDir := t.TempDir()
+		renderer := NewDevRenderer(tempDir, testConfig, BuildDevRenderPlan(testConfig).TemplateNames)
+
+		err := renderer.RenderAll()
+		require.NoError(t, err, "RenderAll should not return error")
+
+		expectedFiles := templateNamesToFiles(BuildDevRenderPlan(testConfig).TemplateNames)
+
+		for _, filename := range expectedFiles {
+			filePath := filepath.Join(tempDir, filename)
+			_, err := os.Stat(filePath)
+			assert.NoError(t, err, "Expected file %s should exist", filename)
+
+			content, err := os.ReadFile(filePath)
+			require.NoError(t, err)
+			assert.NotEmpty(t, content, "File %s should not be empty", filename)
+		}
+	})
+
+	t.Run("skips ingress when HTTP port is unset", func(t *testing.T) {
+		testConfig := &config.DevEnvConfig{
+			Name: "minimal",
+			BaseConfig: config.BaseConfig{
+				SSHPublicKey: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC7... minimal@example.com",
+				Namespace:    "devenv-test",
+			},
+			SSHPort: 30002,
+		}
 
-	tempDir := t.TempDir()
-	renderer := NewDevRenderer(tempDir)
+		tempDir := t.TempDir()
+		renderer := NewDevRenderer(tempDir, testConfig, BuildDevRenderPlan(testConfig).TemplateNames)
+
+		err := renderer.RenderAll()
+		require.NoError(t, err, "RenderAll should not return error")
 
-	// Test RenderAll
-	err := renderer.RenderAll(testConfig)
-	require.NoError(t, err, "RenderAll should not return error")
+		expectedFiles := templateNamesToFiles(BuildDevRenderPlan(testConfig).TemplateNames)
+		for _, filename := range expectedFiles {
+			filePath := filepath.Join(tempDir, filename)
+			_, err := os.Stat(filePath)
+			assert.NoError(t, err, "Expected file %s should exist", filename)
+		}
 
-	// Verify all expected files were created
-	expectedFiles := []string{"statefulset.yaml", "service.yaml", "env-vars.yaml", "startup-scripts.yaml", "ingress.yaml"}
+		_, err = os.Stat(filepath.Join(tempDir, "ingress.yaml"))
+		assert.ErrorIs(t, err, os.ErrNotExist, "ingress.yaml should not be generated without HTTP port")
+	})
 
-	for _, filename := range expectedFiles {
-		filePath := filepath.Join(tempDir, filename)
-		_, err := os.Stat(filePath)
-		assert.NoError(t, err, "Expected file %s should exist", filename)
+	t.Run("preserves stale ingress when render fails", func(t *testing.T) {
+		testConfig := &config.DevEnvConfig{
+			Name: "minimal",
+			BaseConfig: config.BaseConfig{
+				SSHPublicKey: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC7... minimal@example.com",
+				Namespace:    "devenv-test",
+			},
+			SSHPort: 30002,
+		}
+
+		tempDir := t.TempDir()
+		staleIngress := filepath.Join(tempDir, "ingress.yaml")
+		require.NoError(t, os.WriteFile(staleIngress, []byte("stale"), 0o644))
+
+		renderer := NewRenderer[config.DevEnvConfig](
+			tempDir,
+			"template_files/dev",
+			[]string{"nonexistent-template"},
+			testConfig,
+		)
+
+		err := renderer.RenderAll()
+		require.Error(t, err)
+
+		content, readErr := os.ReadFile(staleIngress)
+		require.NoError(t, readErr)
+		assert.Equal(t, "stale", string(content), "stale ingress.yaml should be preserved when render fails")
+	})
+}
 
-		// Verify file is not empty
-		content, err := os.ReadFile(filePath)
-		require.NoError(t, err)
-		assert.NotEmpty(t, content, "File %s should not be empty", filename)
+func templateNamesToFiles(templateNames []string) []string {
+	files := make([]string, 0, len(templateNames))
+	for _, templateName := range templateNames {
+		files = append(files, templateName+".yaml")
 	}
+	return files
 }
 
 // TestRenderTemplate_ErrorCases tests error handling in template rendering
@@ -148,17 +213,19 @@ func TestRenderTemplate_ErrorCases(t *testing.T) {
 
 	t.Run("invalid template name", func(t *testing.T) {
 		tempDir := t.TempDir()
-		renderer := NewDevRenderer(tempDir)
+		renderer := NewDevRenderer(tempDir, testConfig, BuildDevRenderPlan(testConfig).TemplateNames)
 
-		err := renderer.RenderTemplate("nonexistent", testConfig)
+		err := renderer.RenderTemplate("nonexistent")
 		assert.Error(t, err, "Should return error for invalid template")
 	})
 
 	t.Run("invalid output directory", func(t *testing.T) {
-		// Use a path that can't be created (assuming /root is not writable in test)
-		renderer := NewDevRenderer("/root/impossible/path")
+		// Make the parent path a file so MkdirAll fails deterministically.
+		parentFile := filepath.Join(t.TempDir(), "not-a-directory")
+		require.NoError(t, os.WriteFile(parentFile, []byte("x"), 0o644))
+		renderer := NewDevRenderer(filepath.Join(parentFile, "child"), testConfig, BuildDevRenderPlan(testConfig).TemplateNames)
 
-		err := renderer.RenderTemplate("configmap", testConfig)
+		err := renderer.RenderTemplate("env-vars")
 		assert.Error(t, err, "Should return error for invalid output directory")
 	})
 }
diff --git a/internal/templates/testdata/golden/ingress.yaml b/internal/templates/testdata/golden/ingress.yaml
index 4d0c5ba..d8b00e6 100644
--- a/internal/templates/testdata/golden/ingress.yaml
+++ b/internal/templates/testdata/golden/ingress.yaml
@@ -10,7 +10,7 @@ metadata:
 spec:
   ingressClassName: nginx
   rules:
-    - host: testuser.
+    - host: testuser.devenv.example.com
       http:
         paths:
           - path: /
@@ -22,5 +22,5 @@ spec:
                   name: http
   tls:
     - hosts:
-        - "*."
+        - "*.devenv.example.com"
       secretName: http-testuser-tls