Merge pull request #93311 from logicalhan/monitoring-role

Add bootstrap policy for monitoring endpoints

cluster/gce/gci/configure-helper.sh

@@ -699,6 +699,9 @@ function create-master-auth {
     append_or_replace_prefixed_line "${known_tokens_csv}" "${KONNECTIVITY_SERVER_TOKEN},"     "system:konnectivity-server,uid:system:konnectivity-server"
     create-kubeconfig "konnectivity-server" "${KONNECTIVITY_SERVER_TOKEN}"
   fi
+  if [[ -n "${MONITORING_TOKEN:-}" ]]; then
+    append_or_replace_prefixed_line "${known_tokens_csv}" "${MONITORING_TOKEN},"     "system:monitoring,uid:system:monitoring,system:monitoring"
+  fi
 
   if [[ -n "${EXTRA_STATIC_AUTH_COMPONENTS:-}" ]]; then
     # Create a static Bearer token and kubeconfig for extra, comma-separated components.
@@ -2936,7 +2939,9 @@ function main() {
   if [[ "${ENABLE_EGRESS_VIA_KONNECTIVITY_SERVICE:-false}" == "true" ]]; then
     KONNECTIVITY_SERVER_TOKEN="$(secure_random 32)"
   fi
-
+  if [[ "${ENABLE_MONITORING_TOKEN:-false}" == "true" ]]; then
+    MONITORING_TOKEN="$(secure_random 32)"
+  fi
 
   setup-os-params
   config-ip-firewall

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/policy.go

@@ -196,7 +196,8 @@ func ClusterRoles() []rbacv1.ClusterRole {
 			},
 		},
 		{
-			// a role which provides just enough power to determine if the server is ready and discover API versions for negotiation
+			// a role which provides just enough power to determine if the server is
+			// ready and discover API versions for negotiation
 			ObjectMeta: metav1.ObjectMeta{Name: "system:discovery"},
 			Rules: []rbacv1.PolicyRule{
 				rbacv1helpers.NewRule("get").URLs(
@@ -208,6 +209,20 @@ func ClusterRoles() []rbacv1.ClusterRole {
 				).RuleOrDie(),
 			},
 		},
+		{
+			// a role which provides minimal read access to the monitoring endpoints
+			// (i.e. /metrics, /livez/*, /readyz/*, /healthz/*, /livez, /readyz, /healthz)
+			// The splatted health check endpoints allow read access to individual health check
+			// endpoints which may contain more sensitive cluster information information
+			ObjectMeta: metav1.ObjectMeta{Name: "system:monitoring"},
+			Rules: []rbacv1.PolicyRule{
+				rbacv1helpers.NewRule("get").URLs(
+					"/metrics",
+					"/livez", "/readyz", "/healthz",
+					"/livez/*", "/readyz/*", "/healthz/*",
+				).RuleOrDie(),
+			},
+		},
 		{
 			// a role which provides minimal resource access to allow a "normal" user to learn information about themselves
 			ObjectMeta: metav1.ObjectMeta{Name: "system:basic-user"},
@@ -563,6 +578,7 @@ const systemNodeRoleName = "system:node"
 func ClusterRoleBindings() []rbacv1.ClusterRoleBinding {
 	rolebindings := []rbacv1.ClusterRoleBinding{
 		rbacv1helpers.NewClusterBinding("cluster-admin").Groups(user.SystemPrivilegedGroup).BindingOrDie(),
+		rbacv1helpers.NewClusterBinding("system:monitoring").Groups(user.MonitoringGroup).BindingOrDie(),
 		rbacv1helpers.NewClusterBinding("system:discovery").Groups(user.AllAuthenticated).BindingOrDie(),
 		rbacv1helpers.NewClusterBinding("system:basic-user").Groups(user.AllAuthenticated).BindingOrDie(),
 		rbacv1helpers.NewClusterBinding("system:public-info-viewer").Groups(user.AllAuthenticated, user.AllUnauthenticated).BindingOrDie(),

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/testdata/cluster-role-bindings.yaml

@@ -102,6 +102,23 @@ items:
   - apiGroup: rbac.authorization.k8s.io
     kind: User
     name: system:kube-scheduler
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRoleBinding
+  metadata:
+    annotations:
+      rbac.authorization.kubernetes.io/autoupdate: "true"
+    creationTimestamp: null
+    labels:
+      kubernetes.io/bootstrapping: rbac-defaults
+    name: system:monitoring
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: ClusterRole
+    name: system:monitoring
+  subjects:
+  - apiGroup: rbac.authorization.k8s.io
+    kind: Group
+    name: system:monitoring
 - apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRoleBinding
   metadata:

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/testdata/cluster-roles.yaml

@@ -861,6 +861,26 @@ items:
     - nodes/stats
     verbs:
     - '*'
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRole
+  metadata:
+    annotations:
+      rbac.authorization.kubernetes.io/autoupdate: "true"
+    creationTimestamp: null
+    labels:
+      kubernetes.io/bootstrapping: rbac-defaults
+    name: system:monitoring
+  rules:
+  - nonResourceURLs:
+    - /healthz
+    - /healthz/*
+    - /livez
+    - /livez/*
+    - /metrics
+    - /readyz
+    - /readyz/*
+    verbs:
+    - get
 - apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRole
   metadata:

staging/src/k8s.io/apiserver/pkg/authentication/user/user.go

@@ -70,6 +70,7 @@ func (i *DefaultInfo) GetExtra() map[string][]string {
 const (
 	SystemPrivilegedGroup = "system:masters"
 	NodesGroup            = "system:nodes"
+	MonitoringGroup       = "system:monitoring"
 	AllUnauthenticated    = "system:unauthenticated"
 	AllAuthenticated      = "system:authenticated"