Merge pull request #886 from DataDog/JulienBalestra/tls-stream

stream: can use user certificates

docs/config.md

@@ -24,8 +24,16 @@ The explanation and default value of each configuration item are as follows:
   # systemd_cgroup enables systemd cgroup support.
   systemd_cgroup = false
 
-  # enable_tls_streaming enables the TLS streaming support.
+  # enable_tls_streaming enables the TLS streaming support. 
+  # It generates a self-sign certificate unless the following x509_key_pair_streaming are both set.
   enable_tls_streaming = false
+  
+  # "plugins.cri.x509_key_pair_streaming" contains a x509 valid key pair to stream with tls.
+  [plugins.cri.x509_key_pair_streaming]
+    # tls_cert_file is the filepath to the certificate paired with the "tls_key_file"
+    tls_cert_file = ""
+    # tls_key_file is the filepath to the private key paired with the "tls_cert_file"
+    tls_key_file = ""
 
   # max_container_log_line_size is the maximum log line size in bytes for a container.
   # Log line longer than the limit will be split into multiple lines. -1 means no

pkg/config/config.go

@@ -114,12 +114,22 @@ type PluginConfig struct {
 	SystemdCgroup bool `toml:"systemd_cgroup" json:"systemdCgroup"`
 	// EnableTLSStreaming indicates to enable the TLS streaming support.
 	EnableTLSStreaming bool `toml:"enable_tls_streaming" json:"enableTLSStreaming"`
+	// X509KeyPairStreaming is a x509 key pair used for TLS streaming
+	X509KeyPairStreaming `toml:"x509_key_pair_streaming" json:"x509KeyPairStreaming"`
 	// MaxContainerLogLineSize is the maximum log line size in bytes for a container.
 	// Log line longer than the limit will be split into multiple lines. Non-positive
 	// value means no limit.
 	MaxContainerLogLineSize int `toml:"max_container_log_line_size" json:"maxContainerLogSize"`
 }
 
+// X509KeyPairStreaming contains the x509 configuration for streaming
+type X509KeyPairStreaming struct {
+	// TLSCertFile is the path to a certificate file
+	TLSCertFile string `toml:"tls_cert_file" json:"tlsCertFile"`
+	// TLSKeyFile is the path to a private key file
+	TLSKeyFile string `toml:"tls_key_file" json:"tlsKeyFile"`
+}
+
 // Config contains all configurations for cri server.
 type Config struct {
 	// PluginConfig is the config for CRI plugin.
@@ -152,10 +162,14 @@ func DefaultConfig() PluginConfig {
 			},
 			NoPivot: false,
 		},
-		StreamServerAddress:     "127.0.0.1",
+		StreamServerAddress: "127.0.0.1",
-		StreamServerPort:        "0",
+		StreamServerPort:    "0",
-		EnableSelinux:           false,
+		EnableSelinux:       false,
-		EnableTLSStreaming:      false,
+		EnableTLSStreaming:  false,
+		X509KeyPairStreaming: X509KeyPairStreaming{
+			TLSKeyFile:  "",
+			TLSCertFile: "",
+		},
 		SandboxImage:            "k8s.gcr.io/pause:3.1",
 		StatsCollectPeriod:      10,
 		SystemdCgroup:           false,

pkg/server/streaming.go

@@ -34,6 +34,36 @@ import (
 	ctrdutil "github.com/containerd/cri/pkg/containerd/util"
 )
 
+type streamListenerMode int
+
+const (
+	x509KeyPairTLS streamListenerMode = iota
+	selfSignTLS
+	withoutTLS
+)
+
+func getStreamListenerMode(c *criService) (streamListenerMode, error) {
+	if c.config.EnableTLSStreaming {
+		if c.config.X509KeyPairStreaming.TLSCertFile != "" && c.config.X509KeyPairStreaming.TLSKeyFile != "" {
+			return x509KeyPairTLS, nil
+		}
+		if c.config.X509KeyPairStreaming.TLSCertFile != "" && c.config.X509KeyPairStreaming.TLSKeyFile == "" {
+			return -1, errors.New("must set X509KeyPairStreaming.TLSKeyFile")
+		}
+		if c.config.X509KeyPairStreaming.TLSCertFile == "" && c.config.X509KeyPairStreaming.TLSKeyFile != "" {
+			return -1, errors.New("must set X509KeyPairStreaming.TLSCertFile")
+		}
+		return selfSignTLS, nil
+	}
+	if c.config.X509KeyPairStreaming.TLSCertFile != "" {
+		return -1, errors.New("X509KeyPairStreaming.TLSCertFile is set but EnableTLSStreaming is not set")
+	}
+	if c.config.X509KeyPairStreaming.TLSKeyFile != "" {
+		return -1, errors.New("X509KeyPairStreaming.TLSKeyFile is set but EnableTLSStreaming is not set")
+	}
+	return withoutTLS, nil
+}
+
 func newStreamServer(c *criService, addr, port string) (streaming.Server, error) {
 	if addr == "" {
 		a, err := k8snet.ChooseBindAddress(nil)
@@ -44,8 +74,22 @@ func newStreamServer(c *criService, addr, port string) (streaming.Server, error)
 	}
 	config := streaming.DefaultConfig
 	config.Addr = net.JoinHostPort(addr, port)
-	runtime := newStreamRuntime(c)
+	run := newStreamRuntime(c)
-	if c.config.EnableTLSStreaming {
+	tlsMode, err := getStreamListenerMode(c)
+	if err != nil {
+		return nil, errors.Wrapf(err, "invalid stream server configuration")
+	}
+	switch tlsMode {
+	case x509KeyPairTLS:
+		tlsCert, err := tls.LoadX509KeyPair(c.config.X509KeyPairStreaming.TLSCertFile, c.config.X509KeyPairStreaming.TLSKeyFile)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to load x509 key pair for stream server")
+		}
+		config.TLSConfig = &tls.Config{
+			Certificates: []tls.Certificate{tlsCert},
+		}
+		return streaming.NewServer(config, run)
+	case selfSignTLS:
 		tlsCert, err := newTLSCert()
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to generate tls certificate for stream server")
@@ -54,8 +98,12 @@ func newStreamServer(c *criService, addr, port string) (streaming.Server, error)
 			Certificates:       []tls.Certificate{tlsCert},
 			InsecureSkipVerify: true,
 		}
+		return streaming.NewServer(config, run)
+	case withoutTLS:
+		return streaming.NewServer(config, run)
+	default:
+		return nil, errors.New("invalid configuration for the stream listener")
 	}
-	return streaming.NewServer(config, runtime)
 }
 
 type streamRuntime struct {

pkg/server/streaming_test.go

@@ -0,0 +1,153 @@
+/*
+Copyright 2017 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 server
+
+import (
+	"testing"
+
+	"github.com/containerd/cri/pkg/config"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateStreamServer(t *testing.T) {
+	for desc, test := range map[string]struct {
+		*criService
+		tlsMode   streamListenerMode
+		expectErr bool
+	}{
+		"should pass with default withoutTLS": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.DefaultConfig(),
+				},
+			},
+			tlsMode:   withoutTLS,
+			expectErr: false,
+		},
+		"should pass with x509KeyPairTLS": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: true,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "non-empty",
+							TLSCertFile: "non-empty",
+						},
+					},
+				},
+			},
+			tlsMode:   x509KeyPairTLS,
+			expectErr: false,
+		},
+		"should pass with selfSign": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: true,
+					},
+				},
+			},
+			tlsMode:   selfSignTLS,
+			expectErr: false,
+		},
+		"should return error with X509 keypair but not EnableTLSStreaming": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: false,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "non-empty",
+							TLSCertFile: "non-empty",
+						},
+					},
+				},
+			},
+			tlsMode:   -1,
+			expectErr: true,
+		},
+		"should return error with X509 TLSCertFile empty": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: true,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "non-empty",
+							TLSCertFile: "",
+						},
+					},
+				},
+			},
+			tlsMode:   -1,
+			expectErr: true,
+		},
+		"should return error with X509 TLSKeyFile empty": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: true,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "",
+							TLSCertFile: "non-empty",
+						},
+					},
+				},
+			},
+			tlsMode:   -1,
+			expectErr: true,
+		},
+		"should return error without EnableTLSStreaming and only TLSCertFile set": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: false,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "",
+							TLSCertFile: "non-empty",
+						},
+					},
+				},
+			},
+			tlsMode:   -1,
+			expectErr: true,
+		},
+		"should return error without EnableTLSStreaming and only TLSKeyFile set": {
+			criService: &criService{
+				config: config.Config{
+					PluginConfig: config.PluginConfig{
+						EnableTLSStreaming: false,
+						X509KeyPairStreaming: config.X509KeyPairStreaming{
+							TLSKeyFile:  "non-empty",
+							TLSCertFile: "",
+						},
+					},
+				},
+			},
+			tlsMode:   -1,
+			expectErr: true,
+		},
+	} {
+		t.Run(desc, func(t *testing.T) {
+			tlsMode, err := getStreamListenerMode(test.criService)
+			if test.expectErr {
+				assert.Error(t, err)
+				return
+			}
+			assert.NoError(t, err)
+			assert.Equal(t, test.tlsMode, tlsMode)
+		})
+	}
+}