Merge pull request #2 from Webfleet-Solutions/feature/circumvent-insecure-secrets-listing

Feature/circumvent insecure secrets listing

Author: mowoe

helm/charts/k8s-image-availability-exporter/README.md

@@ -4,6 +4,9 @@
 
 This chart bootstraps a [k8s-image-availability-exporter](https://github.com/flant/k8s-image-availability-exporter) deployment on a [Kubernetes](http://kubernetes.io) cluster using the [Helm](https://helm.sh) package manager.
 
+> [!WARNING]  
+> By default, k8s-iae has unconstrained access to **all** secrets in the cluster!
+
 ## Prerequisites
   - Kubernetes 1.12+
   - Helm 2+
@@ -39,6 +42,7 @@ The following tables list the configurable parameters of the k8s-image-availabil
 ### General
 | Parameter | Description | Default |
 | ----- | ----------- | ------ |
+| `k8sImageAvailabilityExporter.useSecretsForPrivateRepositories` | Give k8s-iae unconstrained access to all secrets in the cluster. This is necessary if there are images that are referenced from private registries, which are deployed in pods, where the pull secret is not defined in `spec.imagePullSecrets` in plaintext but rather in an external secret. This setting only modifies the RBAC rules. | `true` |
 | `k8sImageAvailabilityExporter.image.pullPolicy` | Image pull policy to use for the k8s-image-availability-exporter deployment | `IfNotPresent` |
 | `k8sImageAvailabilityExporter.image.repository` | Repository to use for the k8s-image-availability-exporter deployment | `ghcr.io/Webfleet-Solutions/k8s-image-availability-exporter` |
 | `k8sImageAvailabilityExporter.image.tag` | Tag to use for the k8s-image-availability-exporter deployment | `latest` |

helm/charts/k8s-image-availability-exporter/templates/rbac.yaml

@@ -4,6 +4,7 @@ kind: ClusterRole
 metadata:
   name: {{ template "k8s-image-availability-exporter.fullname" . }}
 rules:
+{{- if .Values.k8sImageAvailabilityExporter.useSecretsForPrivateRepositories }}
   - apiGroups:
       - ""
     resources:
@@ -12,6 +13,7 @@ rules:
       - list
       - watch
       - get
+{{- end }}
   - apiGroups:
       - ""
     resources:

helm/charts/k8s-image-availability-exporter/values.yaml

@@ -5,6 +5,7 @@ k8sImageAvailabilityExporter:
     pullPolicy: IfNotPresent
   replicas: 1
   resources: {}
+  useSecretsForPrivateRepositories: true # Setting this to false will prevent k8s-iae having unconstrained cluster-wide secret access
   args:
     - --bind-address=:8080
 

pkg/registry_checker/checker.go

@@ -21,6 +21,7 @@ import (
 	appsv1informers "k8s.io/client-go/informers/apps/v1"
 	batchv1informers "k8s.io/client-go/informers/batch/v1"
 	corev1informers "k8s.io/client-go/informers/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"k8s.io/client-go/informers"
 
@@ -193,7 +194,17 @@ func NewRegistryChecker(
 	}
 	rc.controllerIndexers.cronJobIndexer = rc.cronJobsInformer.Informer().GetIndexer()
 
-	rc.controllerIndexers.secretIndexer = rc.secretsInformer.Informer().GetIndexer()
+	namespace := "default"
+	// Create a context
+	ctx := context.TODO()
+	// Attempt to list secrets in the default namespace
+	_, enumerr := kubeClient.CoreV1().Secrets(namespace).List(ctx, metav1.ListOptions{})
+	if enumerr != nil {
+		// Not add the secret indexer to automatic cache updater
+		logrus.Warn("The provided ServiceAccount is not able to list secrets. The check for images in private registries requires 'spec.imagePullSecrets' to be configured correctly.")
+	} else {
+		rc.controllerIndexers.secretIndexer = rc.secretsInformer.Informer().GetIndexer()
+	}
 
 	go informerFactory.Start(stopCh)
 	logrus.Info("Waiting for cache sync")