fix: fresh objects for Synchronization executions

- snapshots are updated without Event tasks until success Synchronization execution
- fix documentation for "Group" binding context

.github/workflows/tests.yaml

@@ -280,7 +280,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest]
-        k8s_version: [1.16, 1.17]
+        k8s_version: [1.19, 1.20]
     runs-on: ${{ matrix.os }}
     env:
       ACTIONS_ALLOW_UNSECURE_COMMANDS: true

HOOKS.md

@@ -693,13 +693,13 @@ kubernetes:
 
 #### "Synchronization" binding context for group
 
-During startup, the hook will be executed with the "Synchronization" binding context with `snapshots` JSON object:
+During startup, the hook will be executed with the "Group" binding context with `snapshots` JSON object that contains all objects from bindings in the group. Note there is no `objects` field as for "normal" binding:
 
 ```yaml
 [
   {
     "binding": "pods",
-    "type": "Synchronization",
+    "type": "Group",
     "snapshots": {
       "monitor_pods": [
         {
@@ -734,9 +734,9 @@ During startup, the hook will be executed with the "Synchronization" binding con
 ]
 ```
 
-#### "Group" binding context
+#### "Event" binding context for group
 
-If pod `pod-dfbd12` is then added into the "default" namespace, then the hook will be executed with the "Group" binding context:
+Hook is executed on event from every binding in group. So, if pod `pod-dfbd12` is added into the "default" namespace, then the hook will be executed with the "Group" binding context with `snapshots` JSON object that contains all objects from bindings in the group:
 
 ```yaml
 [

pkg/hook/binding_context/binding_context.go

@@ -58,6 +58,7 @@ func (bc BindingContext) MapV1() map[string]interface{} {
 		return res
 	}
 
+	// Set "snapshots" field if needed.
 	if len(bc.Metadata.IncludeSnapshots) > 0 || bc.Metadata.IncludeAllSnapshots {
 		if len(bc.Snapshots) > 0 {
 			res["snapshots"] = bc.Snapshots
@@ -66,6 +67,7 @@ func (bc BindingContext) MapV1() map[string]interface{} {
 		}
 	}
 
+	// Handle validating and conversion before grouping.
 	if bc.Metadata.BindingType == KubernetesValidating {
 		res["type"] = "Validating"
 		res["review"] = bc.AdmissionReview
@@ -80,8 +82,8 @@ func (bc BindingContext) MapV1() map[string]interface{} {
 		return res
 	}
 
-	// KubernetesValidating uses 'group' only for snapshots.
-	if bc.Metadata.Group != "" && bc.Metadata.BindingType != KubernetesValidating {
+	// Group is always has "type: Group", even for Synchronization.
+	if bc.Metadata.Group != "" {
 		res["binding"] = bc.Metadata.Group
 		res["type"] = "Group"
 		return res

pkg/hook/controller/hook_controller.go

@@ -13,14 +13,15 @@ import (
 )
 
 type BindingExecutionInfo struct {
-	BindingContext         []BindingContext
-	IncludeSnapshots       []string
-	IncludeAllSnapshots    bool
-	AllowFailure           bool
-	QueueName              string
-	Binding                string
-	Group                  string
-	WaitForSynchronization bool
+	BindingContext      []BindingContext
+	IncludeSnapshots    []string
+	IncludeAllSnapshots bool
+	AllowFailure        bool
+	QueueName           string
+	Binding             string
+	Group               string
+
+	KubernetesBinding OnKubernetesEventConfig
 }
 
 // В каждый хук надо будет положить этот объект.
@@ -45,15 +46,16 @@ type HookController interface {
 	CanHandleValidatingEvent(event ValidatingEvent) bool
 	CanHandleConversionEvent(event conversion.Event, rule conversion.Rule) bool
 
-	// These method should call underlying BindingController to get binding context
+	// These method should call an underlying *Binding*Controller to get binding context
 	// and then add Snapshots to binding context
 	HandleEnableKubernetesBindings(createTasksFn func(BindingExecutionInfo)) error
 	HandleKubeEvent(event KubeEvent, createTasksFn func(BindingExecutionInfo))
 	HandleScheduleEvent(crontab string, createTasksFn func(BindingExecutionInfo))
 	HandleValidatingEvent(event ValidatingEvent, createTasksFn func(BindingExecutionInfo))
 	HandleConversionEvent(event conversion.Event, rule conversion.Rule, createTasksFn func(BindingExecutionInfo))
 
-	StartMonitors()
+	UnlockKubernetesEvents()
+	UnlockKubernetesEventsFor(monitorID string)
 	StopMonitors()
 
 	EnableScheduleBindings()
@@ -219,9 +221,15 @@ func (hc *hookController) HandleScheduleEvent(crontab string, createTasksFn func
 	}
 }
 
-func (hc *hookController) StartMonitors() {
+func (hc *hookController) UnlockKubernetesEvents() {
 	if hc.KubernetesController != nil {
-		hc.KubernetesController.StartMonitors()
+		hc.KubernetesController.UnlockEvents()
+	}
+}
+
+func (hc *hookController) UnlockKubernetesEventsFor(monitorID string) {
+	if hc.KubernetesController != nil {
+		hc.KubernetesController.UnlockEventsFor(monitorID)
 	}
 }
 
@@ -306,10 +314,17 @@ func (hc *hookController) UpdateSnapshots(context []BindingContext) []BindingCon
 		return context
 	}
 
+	// Turn on cached snapshots mode to retrieve snapshots only once. (Synchronization and self-include)
+	hc.KubernetesController.StartCachedSnapshotMode()
+	defer hc.KubernetesController.StopCachedSnapshotMode()
+
 	newContext := []BindingContext{}
 	for _, bc := range context {
 		newBc := bc
 		newBc.Snapshots = hc.KubernetesSnapshotsFor(bc.Metadata.BindingType, bc.Binding)
+		if newBc.Metadata.BindingType == OnKubernetesEvent && newBc.Type == TypeSynchronization {
+			newBc.Objects = hc.KubernetesController.SnapshotsFor(bc.Binding)
+		}
 		newContext = append(newContext, newBc)
 	}