fix: replace background sa name in config by a flag (#6790)

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

charts/kyverno/README.md

@@ -204,7 +204,6 @@ The command removes all the Kubernetes components associated with the chart and
 | config.defaultRegistry | string | `"docker.io"` | The registry hostname used for the image mutation. |
 | config.excludeGroups | list | `[]` | Exclude groups |
 | config.excludeUsernames | list | `[]` | Exclude usernames |
-| config.excludeBackgroundUsernames | list | `[]` | Exclude usernames for mutateExisting and generate policies |
 | config.generateSuccessEvents | bool | `false` | Generate success events. |
 | config.resourceFilters | list | See [values.yaml](values.yaml) | Resource types to be skipped by the Kyverno policy engine. Make sure to surround each entry in quotes so that it doesn't get parsed as a nested YAML list. These are joined together without spaces, run through `tpl`, and the result is set in the config map. |
 | config.webhooks | list | `[]` | Defines the `namespaceSelector` in the webhook configurations. Note that it takes a list of `namespaceSelector` and/or `objectSelector` in the JSON format, and only the first element will be forwarded to the webhook configurations. The Kyverno namespace is excluded if `excludeKyvernoNamespace` is `true` (default) |

charts/kyverno/templates/admission-controller/deployment.yaml

@@ -119,6 +119,7 @@ spec:
           image: {{ include "kyverno.image" (dict "image" .Values.admissionController.container.image "defaultTag" .Chart.AppVersion) | quote }}
           imagePullPolicy: {{ .Values.admissionController.container.image.pullPolicy }}
           args:
+            - --backgroundServiceAccountName='system:serviceaccount:{{ include "kyverno.namespace" . }}:{{ include "kyverno.background-controller.serviceAccountName" . }}'
             - --servicePort={{ .Values.admissionController.service.port }}
             - --loggingFormat={{ .Values.admissionController.logging.format }}
             {{- if .Values.admissionController.tracing.enabled }}

charts/kyverno/templates/config/configmap.yaml

@@ -28,13 +28,6 @@ data:
   {{- with .Values.config.excludeClusterRoles }}
   excludeClusterRoles: {{ join "," . | quote }}
   {{- end -}}
-  {{- $backgroundUsernames := (printf "system:serviceaccount:%s:%s" (include "kyverno.namespace" .) (include "kyverno.background-controller.serviceAccountName" .)) }}
-  {{- if .Values.config.excludeBackgroundUsernames }}
-  {{- $backgroundUsernames = prepend .Values.config.excludeBackgroundUsernames $backgroundUsernames}}
-  excludeBackgroundUsernames: {{ join "," $backgroundUsernames | quote }}
-  {{- else }}
-  excludeBackgroundUsernames: {{ $backgroundUsernames }}
-  {{- end -}} 
   {{- if .Values.config.resourceFilters }}
   resourceFilters: {{ include "kyverno.config.resourceFilters" . | quote }}
   {{- end -}}

charts/kyverno/values.yaml

@@ -55,9 +55,6 @@ config:
   # -- Exclude usernames
   excludeUsernames: []
 
-  # -- Exclude usernames for mutateExisting and generate policies
-  excludeBackgroundUsernames: []
-
   # -- Generate success events.
   generateSuccessEvents: false
 

cmd/kyverno/main.go

@@ -231,6 +231,7 @@ func main() {
 		enablePolicyException        bool
 		exceptionNamespace           string
 		servicePort                  int
+		backgroundServiceAccountName string
 	)
 	flagset := flag.NewFlagSet("kyverno", flag.ExitOnError)
 	flagset.BoolVar(&dumpPayload, "dumpPayload", false, "Set this flag to activate/deactivate debug mode.")
@@ -250,6 +251,7 @@ func main() {
 	flagset.StringVar(&exceptionNamespace, "exceptionNamespace", "", "Configure the namespace to accept PolicyExceptions.")
 	flagset.BoolVar(&enablePolicyException, "enablePolicyException", false, "Enable PolicyException feature.")
 	flagset.IntVar(&servicePort, "servicePort", 443, "Port used by the Kyverno Service resource and for webhook configurations.")
+	flagset.StringVar(&backgroundServiceAccountName, "backgroundServiceAccountName", "", "Background service account name.")
 	// config
 	appConfig := internal.NewConfiguration(
 		internal.WithProfiling(),
@@ -518,6 +520,7 @@ func main() {
 		eventGenerator,
 		openApiManager,
 		admissionReports,
+		backgroundServiceAccountName,
 	)
 	exceptionHandlers := webhooksexception.NewHandlers(exception.ValidationOptions{
 		Enabled:   enablePolicyException,

config/install-latest-testing.yaml

@@ -66,7 +66,6 @@ data:
   enableDefaultRegistryMutation: "true"
   defaultRegistry: "docker.io"
   generateSuccessEvents: "false"
-  excludeBackgroundUsernames: system:serviceaccount:kyverno:kyverno-background-controller
   resourceFilters: "[*,kyverno,*][Event,*,*][*,kube-system,*][*,kube-public,*][*,kube-node-lease,*][Node,*,*][APIService,*,*][TokenReview,*,*][SubjectAccessReview,*,*][SelfSubjectAccessReview,*,*][Binding,*,*][ReplicaSet,*,*][AdmissionReport,*,*][ClusterAdmissionReport,*,*][BackgroundScanReport,*,*][ClusterBackgroundScanReport,*,*][ClusterRole,*,kyverno:admission-controller][ClusterRole,*,kyverno:admission-controller:core][ClusterRole,*,kyverno:admission-controller:additional][ClusterRole,*,kyverno:background-controller][ClusterRole,*,kyverno:background-controller:core][ClusterRole,*,kyverno:background-controller:additional][ClusterRole,*,kyverno:cleanup-controller][ClusterRole,*,kyverno:cleanup-controller:core][ClusterRole,*,kyverno:cleanup-controller:additional][ClusterRole,*,kyverno:reports-controller][ClusterRole,*,kyverno:reports-controller:core][ClusterRole,*,kyverno:reports-controller:additional][ClusterRoleBinding,*,kyverno:admission-controller][ClusterRoleBinding,*,kyverno:background-controller][ClusterRoleBinding,*,kyverno:cleanup-controller][ClusterRoleBinding,*,kyverno:reports-controller][ServiceAccount,kyverno,kyverno-admission-controller][ServiceAccount,kyverno,kyverno-background-controller][ServiceAccount,kyverno,kyverno-cleanup-controller][ServiceAccount,kyverno,kyverno-reports-controller][Role,kyverno,kyverno:admission-controller][Role,kyverno,kyverno:background-controller][Role,kyverno,kyverno:cleanup-controller][Role,kyverno,kyverno:reports-controller][RoleBinding,kyverno,kyverno:admission-controller][RoleBinding,kyverno,kyverno:background-controller][RoleBinding,kyverno,kyverno:cleanup-controller][RoleBinding,kyverno,kyverno:reports-controller][ConfigMap,kyverno,kyverno][ConfigMap,kyverno,kyverno-metrics][Deployment,kyverno,kyverno-admission-controller][Deployment,kyverno,kyverno-background-controller][Deployment,kyverno,kyverno-cleanup-controller][Deployment,kyverno,kyverno-reports-controller][Pod,kyverno,kyverno-admission-controller-*][Pod,kyverno,kyverno-background-controller-*][Pod,kyverno,kyverno-cleanup-controller-*][Pod,kyverno,kyverno-reports-controller-*][Job,kyverno,kyverno-hook-pre-delete][NetworkPolicy,kyverno,kyverno-admission-controller][NetworkPolicy,kyverno,kyverno-background-controller][NetworkPolicy,kyverno,kyverno-cleanup-controller][NetworkPolicy,kyverno,kyverno-reports-controller][PodDisruptionBudget,kyverno,kyverno-admission-controller][PodDisruptionBudget,kyverno,kyverno-background-controller][PodDisruptionBudget,kyverno,kyverno-cleanup-controller][PodDisruptionBudget,kyverno,kyverno-reports-controller][Service,kyverno,kyverno-svc][Service,kyverno,kyverno-svc-metrics][Service,kyverno,kyverno-background-controller-metrics][Service,kyverno,kyverno-cleanup-controller][Service,kyverno,kyverno-cleanup-controller-metrics][Service,kyverno,kyverno-reports-controller-metrics][ServiceMonitor,kyverno,kyverno-admission-controller][ServiceMonitor,kyverno,kyverno-background-controller][ServiceMonitor,kyverno,kyverno-cleanup-controller][ServiceMonitor,kyverno,kyverno-reports-controller][Secret,kyverno,kyverno-svc.kyverno.svc.*][Secret,kyverno,kyverno-cleanup-controller.kyverno.svc.*]"
   webhooks: '[{"namespaceSelector": {"matchExpressions": [{"key":"kubernetes.io/metadata.name","operator":"NotIn","values":["kyverno"]}]}}]'
 ---
@@ -34610,6 +34609,7 @@ spec:
           image: "ghcr.io/kyverno/kyverno:latest"
           imagePullPolicy: IfNotPresent
           args:
+            - --backgroundServiceAccountName='system:serviceaccount:kyverno:kyverno-background-controller'
             - --servicePort=443
             - --loggingFormat=text
             - --disableMetrics=false

pkg/config/config.go

@@ -147,8 +147,6 @@ type Configuration interface {
 	GetExcludedRoles() []string
 	// GetExcludedClusterRoles return excluded roles
 	GetExcludedClusterRoles() []string
-	// GetExcludedBackgroundUsernames return exclude usernames for mutateExisting and generate policies
-	GetExcludedBackgroundUsernames() []string
 	// GetGenerateSuccessEvents return if should generate success events
 	GetGenerateSuccessEvents() bool
 	// GetWebhooks returns the webhook configs
@@ -168,7 +166,6 @@ type configuration struct {
 	excludedUsernames             []string
 	excludedRoles                 []string
 	excludedClusterRoles          []string
-	excludeBackgroundUsernames    []string
 	filters                       []filter
 	generateSuccessEvents         bool
 	webhooks                      []WebhookConfig
@@ -249,12 +246,6 @@ func (cd *configuration) GetExcludedClusterRoles() []string {
 	return cd.excludedClusterRoles
 }
 
-func (cd *configuration) GetExcludedBackgroundUsernames() []string {
-	cd.mux.RLock()
-	defer cd.mux.RUnlock()
-	return cd.excludeBackgroundUsernames
-}
-
 func (cd *configuration) GetExcludedGroups() []string {
 	cd.mux.RLock()
 	defer cd.mux.RUnlock()
@@ -356,13 +347,6 @@ func (cd *configuration) load(cm *corev1.ConfigMap) {
 	} else {
 		cd.excludedClusterRoles = parseStrings(excludedClusterRoles)
 	}
-	// load excludeBackgroundUsernames
-	excludeBackgroundUsernames, ok := cm.Data["excludeBackgroundUsernames"]
-	if !ok {
-		logger.V(6).Info("configuration: No excludeBackgroundUsernames defined in ConfigMap")
-	} else {
-		cd.excludeBackgroundUsernames = parseStrings(excludeBackgroundUsernames)
-	}
 	// load generateSuccessEvents
 	generateSuccessEvents, ok := cm.Data["generateSuccessEvents"]
 	if ok {

pkg/webhooks/resource/handlers.go

@@ -60,6 +60,7 @@ type resourceHandlers struct {
 	pcBuilder      webhookutils.PolicyContextBuilder
 
 	admissionReports             bool
+	backgroungServiceAccountName string
 }
 
 func NewHandlers(
@@ -80,6 +81,7 @@ func NewHandlers(
 	eventGen event.Interface,
 	openApiManager openapi.ValidateInterface,
 	admissionReports bool,
+	backgroungServiceAccountName string,
 ) webhooks.ResourceHandlers {
 	return &resourceHandlers{
 		engine:                       engine,
@@ -98,6 +100,7 @@ func NewHandlers(
 		openApiManager:               openApiManager,
 		pcBuilder:                    webhookutils.NewPolicyContextBuilder(configuration),
 		admissionReports:             admissionReports,
+		backgroungServiceAccountName: backgroungServiceAccountName,
 	}
 }
 

pkg/webhooks/resource/updaterequest.go

@@ -11,18 +11,15 @@ import (
 	"github.com/kyverno/kyverno/pkg/engine"
 	engineapi "github.com/kyverno/kyverno/pkg/engine/api"
 	"github.com/kyverno/kyverno/pkg/event"
-	"github.com/kyverno/kyverno/pkg/utils/wildcard"
 	"github.com/kyverno/kyverno/pkg/webhooks/resource/generation"
 	admissionv1 "k8s.io/api/admission/v1"
 )
 
 // handleBackgroundApplies applies generate and mutateExisting policies, and creates update requests for background reconcile
 func (h *resourceHandlers) handleBackgroundApplies(ctx context.Context, logger logr.Logger, request admissionv1.AdmissionRequest, policyContext *engine.PolicyContext, generatePolicies, mutatePolicies []kyvernov1.PolicyInterface, ts time.Time) {
-	for _, username := range h.configuration.GetExcludedBackgroundUsernames() {
-		if wildcard.Match(username, policyContext.AdmissionInfo().AdmissionUserInfo.Username) {
+	if h.backgroungServiceAccountName == policyContext.AdmissionInfo().AdmissionUserInfo.Username {
 		return
 	}
-	}
 	go h.handleMutateExisting(ctx, logger, request, mutatePolicies, policyContext, ts)
 	h.handleGenerate(ctx, logger, request, generatePolicies, policyContext, ts)
 }