POC of dynamic authority

Signed-off-by: Erik Godding Boye <[email protected]>
cert-manager · Nov 23, 2024 · 64bfd23 · 64bfd23
1 parent b1a0474
commit 64bfd23
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Showing 13 changed files with 62 additions and 231 deletions.
diff --git a/cmd/trust-manager/app/app.go b/cmd/trust-manager/app/app.go
@@ -17,10 +17,12 @@ limitations under the License.
 package app
 
 import (
+	"crypto/tls"
 	"errors"
 	"fmt"
 	"net/http"
 
+	"github.com/erikgb/dynamic-authority/pkg/authority"
 	"github.com/spf13/cobra"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/labels"
@@ -70,6 +72,8 @@ func NewCommand() *cobra.Command {
 
 			ctrl.SetLogger(mlog)
 
+			certOperator := authority.ServingCertificateOperator{Options: opts.DynamicServing}
+
 			eventBroadcaster := record.NewBroadcaster()
 			eventBroadcaster.StartLogging(func(format string, args ...any) { mlog.V(3).Info(fmt.Sprintf(format, args...)) })
 			eventBroadcaster.StartRecordingToSink(&clientv1.EventSinkImpl{Interface: cl.CoreV1().Events("")})
@@ -87,7 +91,7 @@ func NewCommand() *cobra.Command {
 				WebhookServer: ctrlwebhook.NewServer(ctrlwebhook.Options{
 					Port:    opts.Webhook.Port,
 					Host:    opts.Webhook.Host,
-					CertDir: opts.Webhook.CertDir,
+					TLSOpts: []func(*tls.Config){certOperator.ServingCertificate()},
 				}),
 				Metrics: server.Options{
 					BindAddress: fmt.Sprintf("0.0.0.0:%d", opts.MetricsPort),
@@ -119,6 +123,10 @@ func NewCommand() *cobra.Command {
 				return fmt.Errorf("failed to create manager: %w", err)
 			}
 
+			if err := certOperator.SetupWithManager(mgr); err != nil {
+				return fmt.Errorf("failed to setup cert operator: %w", err)
+			}
+
 			targetCache, err := cache.New(mgr.GetConfig(), cache.Options{
 				HTTPClient:                  mgr.GetHTTPClient(),
 				Scheme:                      mgr.GetScheme(),

diff --git a/cmd/trust-manager/app/options/options.go b/cmd/trust-manager/app/options/options.go
@@ -23,6 +23,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/erikgb/dynamic-authority/pkg/authority"
 	"github.com/go-logr/logr"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -70,6 +71,8 @@ type Options struct {
 
 	// Leader election lease renew duration
 	RenewDeadline time.Duration
+
+	DynamicServing authority.Options
 }
 
 type logOptions struct {
@@ -164,6 +167,7 @@ func (o *Options) addFlags(cmd *cobra.Command) {
 	o.addBundleFlags(nfs.FlagSet("Bundle"))
 	o.addLoggingFlags(nfs.FlagSet("Logging"))
 	o.addWebhookFlags(nfs.FlagSet("Webhook"))
+	o.addDynamicServingFlags(nfs.FlagSet("Dynamic Serving"))
 	o.kubeConfigFlags = genericclioptions.NewConfigFlags(true)
 	o.kubeConfigFlags.AddFlags(nfs.FlagSet("Kubernetes"))
 
@@ -248,3 +252,15 @@ func (o *Options) addWebhookFlags(fs *pflag.FlagSet) {
 			"Certificate and private key must be named 'tls.crt' and 'tls.key' "+
 			"respectively.")
 }
+
+func (o *Options) addDynamicServingFlags(fs *pflag.FlagSet) {
+	fs.StringVar(&o.DynamicServing.Namespace,
+		"dynamic-serving-ca-secret-namespace", "",
+		"Namespace of the secret used to store the CA that signs serving certificates")
+	fs.StringVar(&o.DynamicServing.CASecret,
+		"dynamic-serving-ca-secret-name", "",
+		"Name of the secret used to store the CA that signs serving certificates")
+	fs.StringSliceVar(&o.DynamicServing.DNSNames,
+		"dynamic-serving-dns-names", nil,
+		"DNS names that should be present on certificates generated by the dynamic serving CA")
+}
diff --git a/deploy/charts/trust-manager/README.md b/deploy/charts/trust-manager/README.md
@@ -421,32 +421,6 @@ The nodePort set on the Service used by the webhook.
 > ```
 
 Whether to issue a webhook cert using Helm, which removes the need to install cert-manager. Helm-issued certificates can be challenging to rotate and maintain, and the issued cert will have a duration of 10 years and be modified when trust-manager is updated. It's safer and easier to rely on cert-manager for issuing the webhook cert - avoid using Helm-generated certs in production.
-#### **app.webhook.tls.approverPolicy.enabled** ~ `bool`
-> Default value:
-> ```yaml
-> false
-> ```
-
-Whether to create an approver-policy CertificateRequestPolicy allowing auto-approval of the trust-manager webhook certificate. If you have approver-policy installed, you almost certainly want to enable this.
-#### **app.webhook.tls.approverPolicy.certManagerNamespace** ~ `string`
-> Default value:
-> ```yaml
-> cert-manager
-> ```
-
-The namespace in which cert-manager was installed. Only used if `app.webhook.tls.approverPolicy.enabled` is true.
-#### **app.webhook.tls.approverPolicy.certManagerServiceAccount** ~ `string`
-> Default value:
-> ```yaml
-> cert-manager
-> ```
-
-The name of cert-manager's Service Account. Only used if `app.webhook.tls.approverPolicy.enabled` is true.
-#### **app.webhook.tls.certificate.secretTemplate** ~ `object`
-> Default value:
-> ```yaml
-> {}
-> ```
 #### **app.webhook.hostNetwork** ~ `bool`
 > Default value:
 > ```yaml

diff --git a/deploy/charts/trust-manager/templates/certificate.yaml b/deploy/charts/trust-manager/templates/certificate.yaml
diff --git a/deploy/charts/trust-manager/templates/clusterrole.yaml b/deploy/charts/trust-manager/templates/clusterrole.yaml
@@ -5,6 +5,19 @@ metadata:
     {{- include "trust-manager.labels" . | nindent 4 }}
   name: {{ include "trust-manager.name" . }}
 rules:
+- apiGroups:
+  - "admissionregistration.k8s.io"
+  resources:
+  - "validatingwebhookconfigurations"
+  verbs: ["get", "list", "watch"]
+- apiGroups:
+  - "admissionregistration.k8s.io"
+  resources:
+  - "validatingwebhookconfigurations"
+  verbs: ["patch"]
+  resourceNames:
+  - {{ include "trust-manager.name" . }}
+
 - apiGroups:
   - "trust.cert-manager.io"
   resources:

diff --git a/deploy/charts/trust-manager/templates/deployment.yaml b/deploy/charts/trust-manager/templates/deployment.yaml
@@ -87,7 +87,11 @@ spec:
             # webhook
           - "--webhook-host={{.Values.app.webhook.host}}"
           - "--webhook-port={{.Values.app.webhook.port}}"
-          - "--webhook-certificate-dir=/tls"
+          - "--dynamic-serving-ca-secret-namespace={{ include "trust-manager.namespace" . }}"
+          - "--dynamic-serving-ca-secret-name={{ include "trust-manager.name" . }}-dynamic-ca"
+          - "--dynamic-serving-dns-names={{ include "trust-manager.name" . }}"
+          - "--dynamic-serving-dns-names={{ include "trust-manager.name" . }}.$(POD_NAMESPACE)"
+          - "--dynamic-serving-dns-names={{ include "trust-manager.name" . }}.$(POD_NAMESPACE).svc"
           {{- if .Values.defaultPackage.enabled }}
           - "--default-package-location=/packages/cert-manager-package-debian.json"
           {{- end }}
@@ -97,10 +101,12 @@ spec:
           {{- if .Values.filterExpiredCertificates.enabled }}
           - "--filter-expired-certificates=true"
           {{- end }}
+        env:
+        - name: POD_NAMESPACE
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.namespace
         volumeMounts:
-        - mountPath: /tls
-          name: tls
-          readOnly: true
         - mountPath: /packages
           name: packages
           readOnly: true
@@ -140,10 +146,6 @@ spec:
       - name: packages
         emptyDir:
           sizeLimit: 50M
-      - name: tls
-        secret:
-          defaultMode: 420
-          secretName: {{ include "trust-manager.name" . }}-tls
       {{- if .Values.app.webhook.hostNetwork }}
       hostNetwork: true
       dnsPolicy: ClusterFirstWithHostNet

diff --git a/deploy/charts/trust-manager/templates/role.yaml b/deploy/charts/trust-manager/templates/role.yaml
@@ -14,6 +14,15 @@ rules:
   - "get"
   - "list"
   - "watch"
+- apiGroups:
+  - ""
+  resources:
+  - "secrets"
+  verbs:
+  - "create"
+  - "patch"
+  resourceNames:
+  - {{ include "trust-manager.name" . }}-dynamic-ca
 ---
 kind: Role
 apiVersion: rbac.authorization.k8s.io/v1

diff --git a/deploy/charts/trust-manager/templates/webhook.yaml b/deploy/charts/trust-manager/templates/webhook.yaml
@@ -1,7 +1,3 @@
-{{- if and .Values.app.webhook.tls.helmCert.enabled .Values.app.webhook.tls.approverPolicy.enabled -}}
-{{- fail "cannot set .app.webhook.tls.helmCert.enabled and .Values.app.webhook.tls.approverPolicy.enabled" }}
-{{- end -}}
-
 {{- /*
 $ca is always generated here even if .Values.app.webhook.tls.helmCert.enabled is false because we need it to be
 visible in the scope for the ValidatingWebhookConfiguration below.
@@ -83,10 +79,8 @@ metadata:
   labels:
     app: {{ include "trust-manager.name" . }}
     {{- include "trust-manager.labels" . | nindent 4 }}
-{{ if not .Values.app.webhook.tls.helmCert.enabled }}
-  annotations:
-    cert-manager.io/inject-ca-from: "{{ include "trust-manager.namespace" . }}/{{ include "trust-manager.name" . }}"
-{{ end }}
+    cert-manager.io/inject-dynamic-ca-from-secret-namespace: "{{ include "trust-manager.namespace" . }}"
+    cert-manager.io/inject-dynamic-ca-from-secret-name: "{{ include "trust-manager.name" . }}-dynamic-ca"
 
 webhooks:
   - name: trust.cert-manager.io

diff --git a/deploy/charts/trust-manager/values.schema.json b/deploy/charts/trust-manager/values.schema.json
@@ -389,61 +389,12 @@
     "helm-values.app.webhook.tls": {
       "additionalProperties": false,
       "properties": {
-        "approverPolicy": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.approverPolicy"
-        },
-        "certificate": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.certificate"
-        },
         "helmCert": {
           "$ref": "#/$defs/helm-values.app.webhook.tls.helmCert"
         }
       },
       "type": "object"
     },
-    "helm-values.app.webhook.tls.approverPolicy": {
-      "additionalProperties": false,
-      "properties": {
-        "certManagerNamespace": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.approverPolicy.certManagerNamespace"
-        },
-        "certManagerServiceAccount": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.approverPolicy.certManagerServiceAccount"
-        },
-        "enabled": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.approverPolicy.enabled"
-        }
-      },
-      "type": "object"
-    },
-    "helm-values.app.webhook.tls.approverPolicy.certManagerNamespace": {
-      "default": "cert-manager",
-      "description": "The namespace in which cert-manager was installed. Only used if `app.webhook.tls.approverPolicy.enabled` is true.",
-      "type": "string"
-    },
-    "helm-values.app.webhook.tls.approverPolicy.certManagerServiceAccount": {
-      "default": "cert-manager",
-      "description": "The name of cert-manager's Service Account. Only used if `app.webhook.tls.approverPolicy.enabled` is true.",
-      "type": "string"
-    },
-    "helm-values.app.webhook.tls.approverPolicy.enabled": {
-      "default": false,
-      "description": "Whether to create an approver-policy CertificateRequestPolicy allowing auto-approval of the trust-manager webhook certificate. If you have approver-policy installed, you almost certainly want to enable this.",
-      "type": "boolean"
-    },
-    "helm-values.app.webhook.tls.certificate": {
-      "additionalProperties": false,
-      "properties": {
-        "secretTemplate": {
-          "$ref": "#/$defs/helm-values.app.webhook.tls.certificate.secretTemplate"
-        }
-      },
-      "type": "object"
-    },
-    "helm-values.app.webhook.tls.certificate.secretTemplate": {
-      "default": {},
-      "type": "object"
-    },
     "helm-values.app.webhook.tls.helmCert": {
       "additionalProperties": false,
       "properties": {

diff --git a/deploy/charts/trust-manager/values.yaml b/deploy/charts/trust-manager/values.yaml
@@ -242,26 +242,6 @@ app:
         # It's safer and easier to rely on cert-manager for issuing the webhook cert - avoid using Helm-generated certs in production.
         enabled: false
 
-      approverPolicy:
-        # Whether to create an approver-policy CertificateRequestPolicy allowing auto-approval of the trust-manager webhook certificate. If you have approver-policy installed, you almost certainly want to enable this.
-        enabled: false
-
-        # The namespace in which cert-manager was installed. Only used if `app.webhook.tls.approverPolicy.enabled` is true.
-        certManagerNamespace: "cert-manager"
-
-        # The name of cert-manager's Service Account. Only used if `app.webhook.tls.approverPolicy.enabled` is true.
-        certManagerServiceAccount: "cert-manager"
-
-      # Add labels/annotations to secrets created by Certificate resources when using cert-manager provisioned TLS certificate.
-      certificate:
-        secretTemplate: {}
-          # For example:
-          #   annotations:
-          #     my-secret-annotation-1: "foo"
-          #     my-secret-annotation-2: "bar"
-          #   labels:
-          #     my-secret-label: foo
-
     # This value specifies if the app should be started in hostNetwork mode. It is required for use in some managed Kubernetes clusters (such as AWS EKS) with custom CNI.
     hostNetwork: false