From 7016057ff7a8562829d75e53fe1a719818b4f582 Mon Sep 17 00:00:00 2001
From: xilabao <chenr.fnst@cn.fujitsu.com>
Date: Wed, 9 Nov 2016 10:33:21 +0800
Subject: [PATCH] fix apiserver start failed if lost one of cert and key, add a
 error message

---
 cmd/kubelet/app/server.go      |  7 ++++++-
 pkg/genericapiserver/config.go |  9 ++++++++-
 pkg/util/cert/io.go            | 23 +++++++++++++++++------
 3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/cmd/kubelet/app/server.go b/cmd/kubelet/app/server.go
index 244b92212da..ece05d0cf1d 100644
--- a/cmd/kubelet/app/server.go
+++ b/cmd/kubelet/app/server.go
@@ -514,7 +514,12 @@ func InitializeTLS(kc *componentconfig.KubeletConfiguration) (*server.TLSOptions
 	if kc.TLSCertFile == "" && kc.TLSPrivateKeyFile == "" {
 		kc.TLSCertFile = path.Join(kc.CertDirectory, "kubelet.crt")
 		kc.TLSPrivateKeyFile = path.Join(kc.CertDirectory, "kubelet.key")
-		if !certutil.CanReadCertOrKey(kc.TLSCertFile, kc.TLSPrivateKeyFile) {
+
+		canReadCertAndKey, err := certutil.CanReadCertAndKey(kc.TLSCertFile, kc.TLSPrivateKeyFile)
+		if err != nil {
+			return nil, err
+		}
+		if !canReadCertAndKey {
 			cert, key, err := certutil.GenerateSelfSignedCertKey(nodeutil.GetHostname(kc.HostnameOverride), nil, nil)
 			if err != nil {
 				return nil, fmt.Errorf("unable to generate self signed cert: %v", err)
diff --git a/pkg/genericapiserver/config.go b/pkg/genericapiserver/config.go
index 9fbca9acbc7..b8232382049 100644
--- a/pkg/genericapiserver/config.go
+++ b/pkg/genericapiserver/config.go
@@ -406,7 +406,14 @@ func (c completedConfig) New() (*GenericAPIServer, error) {
 func (c completedConfig) MaybeGenerateServingCerts(alternateIPs ...net.IP) error {
 	// It would be nice to set a fqdn subject alt name, but only the kubelets know, the apiserver is clueless
 	// alternateDNS = append(alternateDNS, "kubernetes.default.svc.CLUSTER.DNS.NAME")
-	if c.SecureServingInfo != nil && c.SecureServingInfo.ServerCert.Generate && !certutil.CanReadCertOrKey(c.SecureServingInfo.ServerCert.CertFile, c.SecureServingInfo.ServerCert.KeyFile) {
+	if c.SecureServingInfo != nil && c.SecureServingInfo.ServerCert.Generate {
+		canReadCertAndKey, err := certutil.CanReadCertAndKey(c.SecureServingInfo.ServerCert.CertFile, c.SecureServingInfo.ServerCert.KeyFile)
+		if err != nil {
+			return err
+		}
+		if canReadCertAndKey {
+			return nil
+		}
 		// TODO (cjcullen): Is ClusterIP the right address to sign a cert with?
 		alternateDNS := []string{"kubernetes.default.svc", "kubernetes.default", "kubernetes", "localhost"}
 
diff --git a/pkg/util/cert/io.go b/pkg/util/cert/io.go
index 9a3e1622f37..377b3d5892f 100644
--- a/pkg/util/cert/io.go
+++ b/pkg/util/cert/io.go
@@ -25,14 +25,25 @@ import (
 	"path/filepath"
 )
 
-// CanReadCertOrKey returns true if the certificate or key files already exists,
-// otherwise returns false.
-func CanReadCertOrKey(certPath, keyPath string) bool {
-	if canReadFile(certPath) || canReadFile(keyPath) {
-		return true
+// CanReadCertAndKey returns true if the certificate and key files already exists,
+// otherwise returns false. If lost one of cert and key, returns error.
+func CanReadCertAndKey(certPath, keyPath string) (bool, error) {
+	certReadable := canReadFile(certPath)
+	keyReadable := canReadFile(keyPath)
+
+	if certReadable == false && keyReadable == false {
+		return false, nil
 	}
 
-	return false
+	if certReadable == false {
+		return false, fmt.Errorf("error reading %s, certificate and key must be supplied as a pair", certPath)
+	}
+
+	if keyReadable == false {
+		return false, fmt.Errorf("error reading %s, certificate and key must be supplied as a pair", keyPath)
+	}
+
+	return true, nil
 }
 
 // If the file represented by path exists and