Refactor certificate controller to make approval an interface

pkg/controller/certificates/groupapprove.go

@@ -0,0 +1,86 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package certificates
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	certificates "k8s.io/kubernetes/pkg/apis/certificates/v1alpha1"
+	clientcertificates "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_5/typed/certificates/v1alpha1"
+	certutil "k8s.io/kubernetes/pkg/util/cert"
+	utilruntime "k8s.io/kubernetes/pkg/util/runtime"
+)
+
+// groupApprover implements AutoApprover for signing Kubelet certificates.
+type groupApprover struct {
+	client                        clientcertificates.CertificateSigningRequestInterface
+	approveAllKubeletCSRsForGroup string
+}
+
+// NewGroupApprover creates an approver that accepts any CSR requests where the subject group contains approveAllKubeletCSRsForGroup.
+func NewGroupApprover(client clientcertificates.CertificateSigningRequestInterface, approveAllKubeletCSRsForGroup string) AutoApprover {
+	return &groupApprover{
+		client: client,
+		approveAllKubeletCSRsForGroup: approveAllKubeletCSRsForGroup,
+	}
+}
+
+func (cc *groupApprover) AutoApprove(csr *certificates.CertificateSigningRequest) (*certificates.CertificateSigningRequest, error) {
+	// short-circuit if we're not auto-approving
+	if cc.approveAllKubeletCSRsForGroup == "" {
+		return csr, nil
+	}
+	// short-circuit if we're already approved or denied
+	if approved, denied := getCertApprovalCondition(&csr.Status); approved || denied {
+		return csr, nil
+	}
+
+	isKubeletBootstrapGroup := false
+	for _, g := range csr.Spec.Groups {
+		if g == cc.approveAllKubeletCSRsForGroup {
+			isKubeletBootstrapGroup = true
+			break
+		}
+	}
+	if !isKubeletBootstrapGroup {
+		return csr, nil
+	}
+
+	x509cr, err := certutil.ParseCSRV1alpha1(csr)
+	if err != nil {
+		utilruntime.HandleError(fmt.Errorf("unable to parse csr %q: %v", csr.Name, err))
+		return csr, nil
+	}
+	if !reflect.DeepEqual([]string{"system:nodes"}, x509cr.Subject.Organization) {
+		return csr, nil
+	}
+	if !strings.HasPrefix(x509cr.Subject.CommonName, "system:node:") {
+		return csr, nil
+	}
+	if len(x509cr.DNSNames)+len(x509cr.EmailAddresses)+len(x509cr.IPAddresses) != 0 {
+		return csr, nil
+	}
+
+	csr.Status.Conditions = append(csr.Status.Conditions, certificates.CertificateSigningRequestCondition{
+		Type:    certificates.CertificateApproved,
+		Reason:  "AutoApproved",
+		Message: "Auto approving of all kubelet CSRs is enabled on the controller manager",
+	})
+	return cc.client.UpdateApproval(csr)
+}