Allow components to generate certificates in-memory

cmd/cloud-controller-manager/app/options/options.go

@@ -44,6 +44,7 @@ import (
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
 	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/master/ports"
+
 	// add the kubernetes feature gates
 	_ "k8s.io/kubernetes/pkg/features"
 )
@@ -102,7 +103,8 @@ func NewCloudControllerManagerOptions() (*CloudControllerManagerOptions, error)
 	s.Authorization.RemoteKubeConfigFileOptional = true
 	s.Authorization.AlwaysAllowPaths = []string{"/healthz"}
 
-	s.SecureServing.ServerCert.CertDirectory = "/var/run/kubernetes"
+	// Set the PairName but leave certificate directory blank to generate in-memory by default
+	s.SecureServing.ServerCert.CertDirectory = ""
 	s.SecureServing.ServerCert.PairName = "cloud-controller-manager"
 	s.SecureServing.BindPort = ports.CloudControllerManagerPort
 

cmd/cloud-controller-manager/app/options/options_test.go

@@ -78,7 +78,7 @@ func TestDefaultFlags(t *testing.T) {
 			BindPort:    10258,
 			BindAddress: net.ParseIP("0.0.0.0"),
 			ServerCert: apiserveroptions.GeneratableKeyCert{
-				CertDirectory: "/var/run/kubernetes",
+				CertDirectory: "",
 				PairName:      "cloud-controller-manager",
 			},
 			HTTP2MaxStreamsPerConnection: 0,

cmd/kube-controller-manager/app/options/options.go

@@ -190,7 +190,8 @@ func NewKubeControllerManagerOptions() (*KubeControllerManagerOptions, error) {
 	s.Authorization.RemoteKubeConfigFileOptional = true
 	s.Authorization.AlwaysAllowPaths = []string{"/healthz"}
 
-	s.SecureServing.ServerCert.CertDirectory = "/var/run/kubernetes"
+	// Set the PairName but leave certificate directory blank to generate in-memory by default
+	s.SecureServing.ServerCert.CertDirectory = ""
 	s.SecureServing.ServerCert.PairName = "kube-controller-manager"
 	s.SecureServing.BindPort = ports.KubeControllerManagerPort
 

staging/src/k8s.io/apiserver/pkg/server/options/serving.go

@@ -75,19 +75,25 @@ type CertKey struct {
 }
 
 type GeneratableKeyCert struct {
+	// CertKey allows setting an explicit cert/key file to use.
 	CertKey CertKey
 
-	// CertDirectory is a directory that will contain the certificates.  If the cert and key aren't specifically set
-	// this will be used to derive a match with the "pair-name"
+	// CertDirectory specifies a directory to write generated certificates to if CertFile/KeyFile aren't explicitly set.
+	// PairName is used to determine the filenames within CertDirectory.
+	// If CertDirectory and PairName are not set, an in-memory certificate will be generated.
 	CertDirectory string
+	// PairName is the name which will be used with CertDirectory to make a cert and key filenames.
+	// It becomes CertDirectory/PairName.crt and CertDirectory/PairName.key
+	PairName string
+
+	// GeneratedCert holds an in-memory generated certificate if CertFile/KeyFile aren't explicitly set, and CertDirectory/PairName are not set.
+	GeneratedCert *tls.Certificate
+
 	// FixtureDirectory is a directory that contains test fixture used to avoid regeneration of certs during tests.
 	// The format is:
 	// <host>_<ip>-<ip>_<alternateDNS>-<alternateDNS>.crt
 	// <host>_<ip>-<ip>_<alternateDNS>-<alternateDNS>.key
 	FixtureDirectory string
-	// PairName is the name which will be used with CertDirectory to make a cert and key names
-	// It becomes CertDirector/PairName.crt and CertDirector/PairName.key
-	PairName string
 }
 
 func NewSecureServingOptions() *SecureServingOptions {
@@ -121,6 +127,10 @@ func (s *SecureServingOptions) Validate() []error {
 		errors = append(errors, fmt.Errorf("--secure-port %v must be between 0 and 65535, inclusive. 0 for turning off secure port", s.BindPort))
 	}
 
+	if (len(s.ServerCert.CertKey.CertFile) != 0 || len(s.ServerCert.CertKey.KeyFile) != 0) && s.ServerCert.GeneratedCert != nil {
+		errors = append(errors, fmt.Errorf("cert/key file and in-memory certificate cannot both be set"))
+	}
+
 	return errors
 }
 
@@ -219,6 +229,8 @@ func (s *SecureServingOptions) ApplyTo(config **server.SecureServingInfo) error
 			return fmt.Errorf("unable to load server certificate: %v", err)
 		}
 		c.Cert = &tlsCert
+	} else if s.ServerCert.GeneratedCert != nil {
+		c.Cert = s.ServerCert.GeneratedCert
 	}
 
 	if len(s.CipherSuites) != 0 {
@@ -264,13 +276,20 @@ func (s *SecureServingOptions) MaybeDefaultWithSelfSignedCerts(publicAddress str
 		return nil
 	}
 
-	keyCert.CertFile = path.Join(s.ServerCert.CertDirectory, s.ServerCert.PairName+".crt")
-	keyCert.KeyFile = path.Join(s.ServerCert.CertDirectory, s.ServerCert.PairName+".key")
-
-	canReadCertAndKey, err := certutil.CanReadCertAndKey(keyCert.CertFile, keyCert.KeyFile)
-	if err != nil {
-		return err
+	canReadCertAndKey := false
+	if len(s.ServerCert.CertDirectory) > 0 {
+		if len(s.ServerCert.PairName) == 0 {
+			return fmt.Errorf("PairName is required if CertDirectory is set")
+		}
+		keyCert.CertFile = path.Join(s.ServerCert.CertDirectory, s.ServerCert.PairName+".crt")
+		keyCert.KeyFile = path.Join(s.ServerCert.CertDirectory, s.ServerCert.PairName+".key")
+		if canRead, err := certutil.CanReadCertAndKey(keyCert.CertFile, keyCert.KeyFile); err != nil {
+			return err
+		} else {
+			canReadCertAndKey = canRead
+		}
 	}
+
 	if !canReadCertAndKey {
 		// add either the bind address or localhost to the valid alternates
 		bindIP := s.BindAddress.String()
@@ -282,15 +301,21 @@ func (s *SecureServingOptions) MaybeDefaultWithSelfSignedCerts(publicAddress str
 
 		if cert, key, err := certutil.GenerateSelfSignedCertKeyWithFixtures(publicAddress, alternateIPs, alternateDNS, s.ServerCert.FixtureDirectory); err != nil {
 			return fmt.Errorf("unable to generate self signed cert: %v", err)
-		} else {
+		} else if len(keyCert.CertFile) > 0 && len(keyCert.KeyFile) > 0 {
 			if err := certutil.WriteCert(keyCert.CertFile, cert); err != nil {
 				return err
 			}
-
 			if err := certutil.WriteKey(keyCert.KeyFile, key); err != nil {
 				return err
 			}
 			glog.Infof("Generated self-signed cert (%s, %s)", keyCert.CertFile, keyCert.KeyFile)
+		} else {
+			tlsCert, err := tls.X509KeyPair(cert, key)
+			if err != nil {
+				return fmt.Errorf("unable to generate self signed cert: %v", err)
+			}
+			s.ServerCert.GeneratedCert = &tlsCert
+			glog.Infof("Generated self-signed cert in-memory")
 		}
 	}