imorove the way extenders are applied

Signed-off-by: Mikhail Scherba <mikhail.scherba@flant.com>

pkg/addon-operator/operator.go

@@ -25,7 +25,7 @@ import (
 	"github.com/flant/addon-operator/pkg/module_manager/models/hooks/kind"
 	"github.com/flant/addon-operator/pkg/module_manager/models/modules"
 	"github.com/flant/addon-operator/pkg/module_manager/models/modules/events"
-	"github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders"
+	kube_config_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/kube_config"
 	"github.com/flant/addon-operator/pkg/task"
 	"github.com/flant/addon-operator/pkg/utils"
 	"github.com/flant/kube-client/client"
@@ -964,7 +964,7 @@ func (op *AddonOperator) StartModuleManagerEventHandler() {
 						eventLogEntry.Debugf("ModuleManagerEventHandler-KubeConfigChanged: GlobalSectionChanged %v, ModuleValuesChanged %s, ModuleEnabledStateChanged %s", event.GlobalSectionChanged, event.ModuleValuesChanged, event.ModuleEnabledStateChanged)
 						newModulesStateChanged := []string{}
 						for _, module := range event.ModuleEnabledStateChanged {
-							stateChanged, err := op.ModuleManager.StateChangedByExtender(extenders.KubeConfigExtender, module)
+							stateChanged, err := op.ModuleManager.StateChangedByExtender(kube_config_extender.Name, module)
 							if err != nil {
 								eventLogEntry.Errorf("Couldn't determine the %s module's new state via KubeConfig extender: %s", module, err)
 								continue

pkg/app/app.go

@@ -42,6 +42,9 @@ var (
 
 	// StrictModeEnabled fail with error if MODULES_DIR/values.yaml does not exist
 	StrictModeEnabled = false
+
+	// AppliedExtenders defines the list and the order of applied module extenders
+	AppliedExtenders = ""
 )
 
 const (
@@ -128,16 +131,21 @@ func DefineStartCommandFlags(kpApp *kingpin.Application, cmd *kingpin.CmdClause)
 		Default("").
 		StringVar(&AdmissionServerCertsDir)
 
-	cmd.Flag("admission-server-enabled", "Flat to enable admission http server.").
+	cmd.Flag("admission-server-enabled", "Flag to enable admission http server.").
 		Envar("ADDON_OPERATOR_ADMISSION_SERVER_ENABLED").
 		Default("false").
 		BoolVar(&AdmissionServerEnabled)
 
-	cmd.Flag("strict-check-values-mode-enabled", "Flat to enable admission http server.").
+	cmd.Flag("strict-check-values-mode-enabled", "Flag to enable strict-check-values mode.").
 		Envar("STRICT_CHECK_VALUES_MODE_ENABLED").
 		Default("false").
 		BoolVar(&StrictModeEnabled)
 
+	cmd.Flag("applied-module-extenders", "Flag to define which module extenders to apply").
+		Envar("ADDON_OPERATOR_APPLIED_MODULE_EXTENDERS").
+		Default(AppliedExtenders).
+		StringVar(&AppliedExtenders)
+
 	sh_app.DefineKubeClientFlags(cmd)
 	sh_app.DefineJqFlags(cmd)
 	sh_app.DefineLoggingFlags(cmd)

pkg/module_manager/module_manager.go

@@ -14,6 +14,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/flant/addon-operator/pkg/addon-operator/converge"
+	"github.com/flant/addon-operator/pkg/app"
 	"github.com/flant/addon-operator/pkg/helm"
 	"github.com/flant/addon-operator/pkg/helm_resources_manager"
 	. "github.com/flant/addon-operator/pkg/hook/types"
@@ -27,10 +28,10 @@ import (
 	"github.com/flant/addon-operator/pkg/module_manager/models/moduleset"
 	"github.com/flant/addon-operator/pkg/module_manager/scheduler"
 	"github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders"
-	"github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/dynamically_enabled"
+	dynamic_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/dynamically_enabled"
 	kube_config_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/kube_config"
-	"github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/script_enabled"
-	"github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/static"
+	script_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/script_enabled"
+	static_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/static"
 	"github.com/flant/addon-operator/pkg/task"
 	"github.com/flant/addon-operator/pkg/utils"
 	. "github.com/flant/shell-operator/pkg/hook/binding_context"
@@ -282,7 +283,7 @@ func (mm *ModuleManager) Init() error {
 		return err
 	}
 
-	staticExtender, err := static.NewExtender(mm.ModulesDir)
+	staticExtender, err := static_extender.NewExtender(mm.ModulesDir)
 	if err != nil {
 		return err
 	}
@@ -300,7 +301,7 @@ func (mm *ModuleManager) Init() error {
 		return err
 	}
 
-	scriptEnabledExtender, err := script_enabled.NewExtender(mm.TempDir)
+	scriptEnabledExtender, err := script_extender.NewExtender(mm.TempDir)
 	if err != nil {
 		return err
 	}
@@ -309,6 +310,11 @@ func (mm *ModuleManager) Init() error {
 		return err
 	}
 
+	// by this point we must have all required scheduler extenders attached
+	if err := mm.moduleScheduler.ApplyExtenders(app.AppliedExtenders); err != nil {
+		return err
+	}
+
 	return mm.registerModules()
 }
 
@@ -789,7 +795,7 @@ func (mm *ModuleManager) LoopByBinding(binding BindingType, fn func(gh *hooks.Gl
 	return nil
 }
 
-func (mm *ModuleManager) runDynamicEnabledLoop(extender *dynamically_enabled.Extender) {
+func (mm *ModuleManager) runDynamicEnabledLoop(extender *dynamic_extender.Extender) {
 	for report := range mm.global.EnabledReportChannel() {
 		err := mm.applyEnabledPatch(report.Patch, extender)
 		report.Done <- err
@@ -798,7 +804,7 @@ func (mm *ModuleManager) runDynamicEnabledLoop(extender *dynamically_enabled.Ext
 
 // applyEnabledPatch changes "dynamicEnabled" map with patches.
 // TODO: can add some optimization here
-func (mm *ModuleManager) applyEnabledPatch(enabledPatch utils.ValuesPatch, extender *dynamically_enabled.Extender) error {
+func (mm *ModuleManager) applyEnabledPatch(enabledPatch utils.ValuesPatch, extender *dynamic_extender.Extender) error {
 	for _, op := range enabledPatch.Operations {
 		// Extract module name from json patch: '"path": "/moduleNameEnabled"'
 		modName := strings.TrimSuffix(op.Path, "Enabled")
@@ -830,13 +836,13 @@ func (mm *ModuleManager) applyEnabledPatch(enabledPatch utils.ValuesPatch, exten
 
 // DynamicEnabledChecksum returns checksum for dynamicEnabled map
 func (mm *ModuleManager) DynamicEnabledChecksum() string {
-	jsonBytes, _ := json.Marshal(mm.moduleScheduler.DumpExtender(extenders.DynamicallyEnabledExtender))
+	jsonBytes, _ := json.Marshal(mm.moduleScheduler.DumpExtender(dynamic_extender.Name))
 	return utils_checksum.CalculateChecksum(string(jsonBytes))
 }
 
 func (mm *ModuleManager) DumpDynamicEnabled() string {
 	dump := "["
-	for k, v := range mm.moduleScheduler.DumpExtender(extenders.DynamicallyEnabledExtender) {
+	for k, v := range mm.moduleScheduler.DumpExtender(dynamic_extender.Name) {
 		dump += fmt.Sprintf("%s(%t), ", k, v)
 	}
 	return dump + "]"

pkg/module_manager/module_manager_hooks.go

@@ -10,7 +10,7 @@ import (
 
 	"github.com/flant/addon-operator/pkg/module_manager/models/hooks"
 	"github.com/flant/addon-operator/pkg/module_manager/models/modules"
-	dynamically_enabled_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/dynamically_enabled"
+	dynamic_extender "github.com/flant/addon-operator/pkg/module_manager/scheduler/extenders/dynamically_enabled"
 	"github.com/flant/addon-operator/pkg/utils"
 	"github.com/flant/shell-operator/pkg/hook/controller"
 	sh_op_types "github.com/flant/shell-operator/pkg/hook/types"
@@ -94,7 +94,7 @@ func (mm *ModuleManager) registerGlobalModule(globalValues utils.Values, configB
 	log.Infof(gm.GetSchemaStorage().GlobalSchemasDescription())
 
 	// applies a scheduler extender to follow which modules get enabled/disabled by dynamic patches
-	dynamicExtender := dynamically_enabled_extender.NewExtender()
+	dynamicExtender := dynamic_extender.NewExtender()
 	if err := mm.moduleScheduler.AddExtender(dynamicExtender); err != nil {
 		return err
 	}

pkg/module_manager/scheduler/extenders/dynamically_enabled/dynamic.go

@@ -9,6 +9,10 @@ import (
 	"github.com/flant/addon-operator/pkg/module_manager/scheduler/node"
 )
 
+const (
+	Name extenders.ExtenderName = "DynamicallyEnabled"
+)
+
 type Extender struct {
 	l             sync.RWMutex
 	modulesStatus map[string]bool
@@ -41,7 +45,7 @@ func (e *Extender) UpdateStatus(moduleName, operation string, value bool) {
 }
 
 func (e *Extender) Name() extenders.ExtenderName {
-	return extenders.DynamicallyEnabledExtender
+	return Name
 }
 
 func (e *Extender) Filter(module node.ModuleInterface) (*bool, error) {
@@ -59,8 +63,5 @@ func (e *Extender) IsNotifier() bool {
 	return false
 }
 
-//func (e *Extender) SetNotifyChannel(_ context.Context, _ chan extenders.ExtenderEvent) {
-//}
-
 func (e *Extender) Order() {
 }

pkg/module_manager/scheduler/extenders/extenders.go

@@ -35,10 +35,3 @@ type ResettableExtender interface {
 	// Reset resets the extender's cache
 	Reset()
 }
-
-const (
-	StaticExtender             ExtenderName = "Static"
-	DynamicallyEnabledExtender ExtenderName = "DynamicallyEnabled"
-	KubeConfigExtender         ExtenderName = "KubeConfig"
-	ScriptEnabledExtender      ExtenderName = "ScriptEnabled"
-)

pkg/module_manager/scheduler/extenders/kube_config/kube_config.go

@@ -8,6 +8,10 @@ import (
 	"github.com/flant/addon-operator/pkg/module_manager/scheduler/node"
 )
 
+const (
+	Name extenders.ExtenderName = "KubeConfig"
+)
+
 type kubeConfigManager interface {
 	IsModuleEnabled(moduleName string) *bool
 	KubeConfigEventCh() chan config.KubeConfigEvent
@@ -31,7 +35,7 @@ func (e Extender) Dump() map[string]bool {
 }
 
 func (e Extender) Name() extenders.ExtenderName {
-	return extenders.KubeConfigExtender
+	return Name
 }
 
 func (e Extender) Filter(module node.ModuleInterface) (*bool, error) {

pkg/module_manager/scheduler/extenders/script_enabled/script.go

@@ -9,6 +9,10 @@ import (
 	"github.com/flant/addon-operator/pkg/module_manager/scheduler/node"
 )
 
+const (
+	Name extenders.ExtenderName = "ScriptEnabled"
+)
+
 type Extender struct {
 	tmpDir string
 
@@ -45,7 +49,7 @@ func (e *Extender) Dump() map[string]bool {
 }
 
 func (e *Extender) Name() extenders.ExtenderName {
-	return extenders.ScriptEnabledExtender
+	return Name
 }
 
 func (e *Extender) IsShutter() bool {

pkg/module_manager/scheduler/extenders/static/static.go

@@ -14,6 +14,10 @@ import (
 	"github.com/flant/addon-operator/pkg/utils"
 )
 
+const (
+	Name extenders.ExtenderName = "Static"
+)
+
 type Extender struct {
 	modulesStatus map[string]bool
 }
@@ -72,7 +76,7 @@ func (e Extender) Dump() map[string]bool {
 }
 
 func (e Extender) Name() extenders.ExtenderName {
-	return extenders.StaticExtender
+	return Name
 }
 
 func (e Extender) Filter(module node.ModuleInterface) (*bool, error) {
@@ -87,8 +91,5 @@ func (e *Extender) IsNotifier() bool {
 	return false
 }
 
-//func (e *Extender) SetNotifyChannel(_ context.Context, _ chan extenders.ExtenderEvent) {
-//}
-
 func (e Extender) Order() {
 }