From 544cd03f9d0abac70423db231397c2f4188b8cf8 Mon Sep 17 00:00:00 2001
From: James Peach <james.peach@konghq.com>
Date: Mon, 12 Jul 2021 11:19:23 +1000
Subject: [PATCH] chore(*) improve resource manager initialization readability
 (#2316)

Signed-off-by: James Peach <james.peach@konghq.com>
---
 pkg/core/bootstrap/bootstrap.go               | 47 ++++++++++++-------
 .../resources/manager/customizable_manager.go |  5 ++
 2 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/pkg/core/bootstrap/bootstrap.go b/pkg/core/bootstrap/bootstrap.go
index a937e1ac2442..eae60718318d 100644
--- a/pkg/core/bootstrap/bootstrap.go
+++ b/pkg/core/bootstrap/bootstrap.go
@@ -287,28 +287,36 @@ func initializeCaManagers(builder *core_runtime.Builder) error {
 
 func initializeResourceManager(cfg kuma_cp.Config, builder *core_runtime.Builder) error {
 	defaultManager := core_manager.NewResourceManager(builder.ResourceStore())
-	customManagers := map[core_model.ResourceType]core_manager.ResourceManager{}
-	customizableManager := core_manager.NewCustomizableResourceManager(defaultManager, customManagers)
+	customizableManager := core_manager.NewCustomizableResourceManager(defaultManager, nil)
 
 	meshValidator := mesh_managers.MeshValidator{
 		CaManagers: builder.CaManagers(),
 		Store:      builder.ResourceStore(),
 	}
-	meshManager := mesh_managers.NewMeshManager(builder.ResourceStore(), customizableManager, builder.CaManagers(), registry.Global(), meshValidator)
-	customManagers[mesh.MeshType] = meshManager
+	customizableManager.Customize(
+		mesh.MeshType,
+		mesh_managers.NewMeshManager(builder.ResourceStore(), customizableManager, builder.CaManagers(), registry.Global(), meshValidator),
+	)
 
-	dpManager := dataplane.NewDataplaneManager(builder.ResourceStore(), builder.Config().Multizone.Zone.Name)
-	customManagers[mesh.DataplaneType] = dpManager
+	customizableManager.Customize(
+		mesh.DataplaneType,
+		dataplane.NewDataplaneManager(builder.ResourceStore(), builder.Config().Multizone.Zone.Name),
+	)
 
-	dpInsightManager := dataplaneinsight.NewDataplaneInsightManager(builder.ResourceStore(), builder.Config().Metrics.Dataplane)
-	customManagers[mesh.DataplaneInsightType] = dpInsightManager
+	customizableManager.Customize(
+		mesh.DataplaneInsightType,
+		dataplaneinsight.NewDataplaneInsightManager(builder.ResourceStore(), builder.Config().Metrics.Dataplane),
+	)
 
-	zoneValidator := zone.Validator{Store: builder.ResourceStore()}
-	zoneManager := zone.NewZoneManager(builder.ResourceStore(), zoneValidator)
-	customManagers[system.ZoneType] = zoneManager
+	customizableManager.Customize(
+		system.ZoneType,
+		zone.NewZoneManager(builder.ResourceStore(), zone.Validator{Store: builder.ResourceStore()}),
+	)
 
-	zoneInsightManager := zoneinsight.NewZoneInsightManager(builder.ResourceStore(), builder.Config().Metrics.Zone)
-	customManagers[system.ZoneInsightType] = zoneInsightManager
+	customizableManager.Customize(
+		system.ZoneInsightType,
+		zoneinsight.NewZoneInsightManager(builder.ResourceStore(), builder.Config().Metrics.Zone),
+	)
 
 	var cipher secret_cipher.Cipher
 	switch cfg.Store.Type {
@@ -326,9 +334,16 @@ func initializeResourceManager(cfg kuma_cp.Config, builder *core_runtime.Builder
 	default:
 		secretValidator = secret_manager.NewSecretValidator(builder.CaManagers(), builder.ResourceStore())
 	}
-	secretManager := secret_manager.NewSecretManager(builder.SecretStore(), cipher, secretValidator)
-	customManagers[system.SecretType] = secretManager
-	customManagers[system.GlobalSecretType] = secret_manager.NewGlobalSecretManager(builder.SecretStore(), cipher)
+
+	customizableManager.Customize(
+		system.SecretType,
+		secret_manager.NewSecretManager(builder.SecretStore(), cipher, secretValidator),
+	)
+
+	customizableManager.Customize(
+		system.GlobalSecretType,
+		secret_manager.NewGlobalSecretManager(builder.SecretStore(), cipher),
+	)
 
 	builder.WithResourceManager(customizableManager)
 
diff --git a/pkg/core/resources/manager/customizable_manager.go b/pkg/core/resources/manager/customizable_manager.go
index 6f9ce0a584df..60ac8c3b473b 100644
--- a/pkg/core/resources/manager/customizable_manager.go
+++ b/pkg/core/resources/manager/customizable_manager.go
@@ -14,6 +14,9 @@ type CustomizableResourceManager interface {
 }
 
 func NewCustomizableResourceManager(defaultManager ResourceManager, customManagers map[model.ResourceType]ResourceManager) CustomizableResourceManager {
+	if customManagers == nil {
+		customManagers = map[model.ResourceType]ResourceManager{}
+	}
 	return &customizableResourceManager{
 		defaultManager: defaultManager,
 		customManagers: customManagers,
@@ -27,6 +30,8 @@ type customizableResourceManager struct {
 	customManagers map[model.ResourceType]ResourceManager
 }
 
+// Customize installs a new manager for the given type, overwriting any
+// existing manager for that type.
 func (m *customizableResourceManager) Customize(resourceType model.ResourceType, manager ResourceManager) {
 	m.customManagers[resourceType] = manager
 }