✨ Admission webhook to restrict usage of kapp-controller APIs

PROJECT

@@ -1,3 +1,7 @@
+# Code generated by tool. DO NOT EDIT.
+# This file is used to track the info used to scaffold your project
+# and allow the plugins properly work.
+# More info: https://book.kubebuilder.io/reference/project-config.html
 domain: operatorframework.io
 layout:
 - go.kubebuilder.io/v4

cmd/manager/main.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"strings"
 	"time"
 
 	catalogd "github.com/operator-framework/catalogd/api/core/v1alpha1"
@@ -46,6 +47,7 @@ import (
 	"github.com/operator-framework/operator-controller/internal/catalogmetadata/cache"
 	catalogclient "github.com/operator-framework/operator-controller/internal/catalogmetadata/client"
 	"github.com/operator-framework/operator-controller/internal/controllers"
+	"github.com/operator-framework/operator-controller/internal/webhook"
 	"github.com/operator-framework/operator-controller/pkg/features"
 )
 
@@ -71,13 +73,16 @@ func main() {
 		enableLeaderElection bool
 		probeAddr            string
 		cachePath            string
+		allowServiceAccounts commaSeparatedValue
 	)
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.StringVar(&cachePath, "cache-path", "/var/cache", "The local directory path used for filesystem based caching")
+	flag.Var(&allowServiceAccounts, "allow-service-account-names", "Comma-separated names of service accounts which are allowed to make create, update and delete Carvel kapp resources.")
+
 	opts := zap.Options{
 		Development: true,
 	}
@@ -145,6 +150,14 @@ func main() {
 		setupLog.Error(err, "unable to create controller", "controller", "Extension")
 		os.Exit(1)
 	}
+	if os.Getenv("ENABLE_WEBHOOKS") != "false" {
+		if err = (&webhook.KAppUserInfo{
+			WhitelistedUsernames: allowServiceAccounts,
+		}).SetupWebhookWithManager(mgr); err != nil {
+			setupLog.Error(err, "unable to create webhook", "webhook", "KAppUserInfo")
+			os.Exit(1)
+		}
+	}
 	//+kubebuilder:scaffold:builder
 
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
@@ -186,3 +199,14 @@ func hasKappApis(config *rest.Config) (bool, error) {
 	}
 	return false, nil
 }
+
+type commaSeparatedValue []string
+
+func (v *commaSeparatedValue) String() string {
+	return strings.Join(*v, ",")
+}
+
+func (v *commaSeparatedValue) Set(value string) error {
+	*v = strings.Split(value, ",")
+	return nil
+}

config/certmanager/certificate.yaml

@@ -0,0 +1,39 @@
+# The following manifests contain a self-signed issuer CR and a certificate CR.
+# More document can be found at https://docs.cert-manager.io
+# WARNING: Targets CertManager v1.0. Check https://cert-manager.io/docs/installation/upgrading/ for breaking changes.
+apiVersion: cert-manager.io/v1
+kind: Issuer
+metadata:
+  labels:
+    app.kubernetes.io/name: certificate
+    app.kubernetes.io/instance: serving-cert
+    app.kubernetes.io/component: certificate
+    app.kubernetes.io/created-by: operator-controller
+    app.kubernetes.io/part-of: operator-controller
+    app.kubernetes.io/managed-by: kustomize
+  name: selfsigned-issuer
+  namespace: system
+spec:
+  selfSigned: {}
+---
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  labels:
+    app.kubernetes.io/name: certificate
+    app.kubernetes.io/instance: serving-cert
+    app.kubernetes.io/component: certificate
+    app.kubernetes.io/created-by: operator-controller
+    app.kubernetes.io/part-of: operator-controller
+    app.kubernetes.io/managed-by: kustomize
+  name: serving-cert  # this name should match the one appeared in kustomizeconfig.yaml
+  namespace: system
+spec:
+  # SERVICE_NAME and SERVICE_NAMESPACE will be substituted by kustomize
+  dnsNames:
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc.cluster.local
+  issuerRef:
+    kind: Issuer
+    name: selfsigned-issuer
+  secretName: webhook-server-cert # this secret will not be prefixed, since it's not managed by kustomize

config/certmanager/kustomization.yaml

@@ -0,0 +1,5 @@
+resources:
+- certificate.yaml
+
+configurations:
+- kustomizeconfig.yaml

config/certmanager/kustomizeconfig.yaml

@@ -0,0 +1,8 @@
+# This configuration is for teaching kustomize how to update name ref substitution
+nameReference:
+- kind: Issuer
+  group: cert-manager.io
+  fieldSpecs:
+  - kind: Certificate
+    group: cert-manager.io
+    path: spec/issuerRef/name

config/crd/kustomization.yaml

@@ -5,6 +5,8 @@ resources:
 - bases/olm.operatorframework.io_clusterextensions.yaml
 - bases/olm.operatorframework.io_extensions.yaml
 
+#+kubebuilder:scaffold:crdkustomizewebhookpatch
+
 # the following config is for teaching kustomize how to do kustomization for CRDs.
 configurations:
 - kustomizeconfig.yaml

config/default/cert_manager_replacement.yaml

@@ -0,0 +1,96 @@
+- source: # Add cert-manager annotation to ValidatingWebhookConfiguration, MutatingWebhookConfiguration and CRDs
+    kind: Certificate
+    group: cert-manager.io
+    version: v1
+    name: serving-cert # this name should match the one in certificate.yaml
+    fieldPath: .metadata.namespace # namespace of the certificate CR
+  targets:
+    - select:
+        kind: ValidatingWebhookConfiguration
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 0
+        create: true
+    - select:
+        kind: MutatingWebhookConfiguration
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 0
+        create: true
+    - select:
+        kind: CustomResourceDefinition
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 0
+        create: true
+- source:
+    kind: Certificate
+    group: cert-manager.io
+    version: v1
+    name: serving-cert # this name should match the one in certificate.yaml
+    fieldPath: .metadata.name
+  targets:
+    - select:
+        kind: ValidatingWebhookConfiguration
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 1
+        create: true
+    - select:
+        kind: MutatingWebhookConfiguration
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 1
+        create: true
+    - select:
+        kind: CustomResourceDefinition
+      fieldPaths:
+        - .metadata.annotations.[cert-manager.io/inject-ca-from]
+      options:
+        delimiter: "/"
+        index: 1
+        create: true
+- source: # Add cert-manager annotation to the webhook Service
+    kind: Service
+    version: v1
+    name: webhook-service
+    fieldPath: .metadata.name # namespace of the service
+  targets:
+    - select:
+        kind: Certificate
+        group: cert-manager.io
+        version: v1
+      fieldPaths:
+        - .spec.dnsNames.0
+        - .spec.dnsNames.1
+      options:
+        delimiter: "."
+        index: 0
+        create: true
+- source:
+    kind: Service
+    version: v1
+    name: webhook-service
+    fieldPath: .metadata.namespace # namespace of the service
+  targets:
+    - select:
+        kind: Certificate
+        group: cert-manager.io
+        version: v1
+      fieldPaths:
+        - .spec.dnsNames.0
+        - .spec.dnsNames.1
+      options:
+        delimiter: "."
+        index: 1
+        create: true

config/default/kustomization.yaml

@@ -18,119 +18,15 @@ resources:
 - ../crd
 - ../rbac
 - ../manager
-# [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
-# crd/kustomization.yaml
-#- ../webhook
-# [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER'. 'WEBHOOK' components are required.
-#- ../certmanager
+- ../webhook
+- ../certmanager
 # [PROMETHEUS] To enable prometheus monitor, uncomment all sections with 'PROMETHEUS'.
 #- ../prometheus
 
-# [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
-# crd/kustomization.yaml
-#- manager_webhook_patch.yaml
+patches:
+- path: manager_webhook_patch.yaml
+- path: webhookcainjection_patch.yaml
 
-# [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER'.
-# Uncomment 'CERTMANAGER' sections in crd/kustomization.yaml to enable the CA injection in the admission webhooks.
-# 'CERTMANAGER' needs to be enabled to use ca injection
-#- webhookcainjection_patch.yaml
-
-# [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER' prefix.
-# Uncomment the following replacements to add the cert-manager CA injection annotations
-#replacements:
-#  - source: # Add cert-manager annotation to ValidatingWebhookConfiguration, MutatingWebhookConfiguration and CRDs
-#      kind: Certificate
-#      group: cert-manager.io
-#      version: v1
-#      name: serving-cert # this name should match the one in certificate.yaml
-#      fieldPath: .metadata.namespace # namespace of the certificate CR
-#    targets:
-#      - select:
-#          kind: ValidatingWebhookConfiguration
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 0
-#          create: true
-#      - select:
-#          kind: MutatingWebhookConfiguration
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 0
-#          create: true
-#      - select:
-#          kind: CustomResourceDefinition
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 0
-#          create: true
-#  - source:
-#      kind: Certificate
-#      group: cert-manager.io
-#      version: v1
-#      name: serving-cert # this name should match the one in certificate.yaml
-#      fieldPath: .metadata.name
-#    targets:
-#      - select:
-#          kind: ValidatingWebhookConfiguration
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 1
-#          create: true
-#      - select:
-#          kind: MutatingWebhookConfiguration
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 1
-#          create: true
-#      - select:
-#          kind: CustomResourceDefinition
-#        fieldPaths:
-#          - .metadata.annotations.[cert-manager.io/inject-ca-from]
-#        options:
-#          delimiter: '/'
-#          index: 1
-#          create: true
-#  - source: # Add cert-manager annotation to the webhook Service
-#      kind: Service
-#      version: v1
-#      name: webhook-service
-#      fieldPath: .metadata.name # namespace of the service
-#    targets:
-#      - select:
-#          kind: Certificate
-#          group: cert-manager.io
-#          version: v1
-#        fieldPaths:
-#          - .spec.dnsNames.0
-#          - .spec.dnsNames.1
-#        options:
-#          delimiter: '.'
-#          index: 0
-#          create: true
-#  - source:
-#      kind: Service
-#      version: v1
-#      name: webhook-service
-#      fieldPath: .metadata.namespace # namespace of the service
-#    targets:
-#      - select:
-#          kind: Certificate
-#          group: cert-manager.io
-#          version: v1
-#        fieldPaths:
-#          - .spec.dnsNames.0
-#          - .spec.dnsNames.1
-#        options:
-#          delimiter: '.'
-#          index: 1
-#          create: true
+replacements:
+- path: cert_manager_replacement.yaml
+- path: manager_config_replacement.yaml

config/default/manager_config_replacement.yaml

@@ -0,0 +1,34 @@
+# Add operator-controller's service account into ConfigMap
+
+- source:
+    kind: ServiceAccount
+    version: v1
+    name: controller-manager
+    namespace: system
+    fieldPath: .metadata.namespace
+  targets:
+    - select:
+        kind: ConfigMap
+        version: v1
+      fieldPaths:
+        - .data.operator-controller-service-account-name
+      options:
+        delimiter: ":"
+        index: 2
+        create: true
+- source:
+    kind: ServiceAccount
+    version: v1
+    name: controller-manager
+    namespace: system
+    fieldPath: .metadata.name
+  targets:
+    - select:
+        kind: ConfigMap
+        version: v1
+      fieldPaths:
+        - .data.operator-controller-service-account-name
+      options:
+        delimiter: ":"
+        index: 3
+        create: true