Add options to run metrics endpoint over HTTPS

Signed-off-by: Connor Catlett <[email protected]>

cmd/main.go

@@ -130,7 +130,7 @@ func main() {
 
 	if options.HttpEndpoint != "" {
 		r := metrics.InitializeRecorder()
-		r.InitializeMetricsHandler(options.HttpEndpoint, "/metrics")
+		r.InitializeMetricsHandler(options.HttpEndpoint, "/metrics", options.MetricsCertFile, options.MetricsKeyFile)
 	}
 
 	cfg := metadata.MetadataServiceConfig{

pkg/driver/options.go

@@ -34,6 +34,10 @@ type Options struct {
 	Endpoint string
 	// HttpEndpoint is the TCP network address where the HTTP server for metrics will listen
 	HttpEndpoint string
+	// MetricsCertFile is the location of the certificate for serving the metrics server over HTTPS
+	MetricsCertFile string
+	// MetricsKeyFile is the location of the key for serving the metrics server over HTTPS
+	MetricsKeyFile string
 	// EnableOtelTracing is a flag to enable opentelemetry tracing for the driver
 	EnableOtelTracing bool
 
@@ -83,6 +87,8 @@ func (o *Options) AddFlags(f *flag.FlagSet) {
 	// Server options
 	f.StringVar(&o.Endpoint, "endpoint", DefaultCSIEndpoint, "Endpoint for the CSI driver server")
 	f.StringVar(&o.HttpEndpoint, "http-endpoint", "", "The TCP network address where the HTTP server for metrics will listen (example: `:8080`). The default is empty string, which means the server is disabled.")
+	f.StringVar(&o.MetricsCertFile, "metrics-cert-file", "", "The path to a certificate to use for serving the metrics server over HTTPS. If the certificate is signed by a certificate authority, this file should be the concatenation of the server's certificate, any intermediates, and the CA's certificate. If this is non-empty, --http-endpoint and --metrics-key-file MUST also be non-empty.")
+	f.StringVar(&o.MetricsKeyFile, "metrics-key-file", "", "The path to a key to use for serving the metrics server over HTTPS. If this is non-empty, --http-endpoint and --metrics-cert-file MUST also be non-empty.")
 	f.BoolVar(&o.EnableOtelTracing, "enable-otel-tracing", false, "To enable opentelemetry tracing for the driver. The tracing is disabled by default. Configure the exporter endpoint with OTEL_EXPORTER_OTLP_ENDPOINT and other env variables, see https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#general-sdk-configuration.")
 
 	// Controller options
@@ -104,8 +110,21 @@ func (o *Options) AddFlags(f *flag.FlagSet) {
 }
 
 func (o *Options) Validate() error {
-	if o.VolumeAttachLimit != -1 && o.ReservedVolumeAttachments != -1 {
-		return fmt.Errorf("only one of --volume-attach-limit and --reserved-volume-attachments may be specified")
+	if o.Mode == AllMode || o.Mode == NodeMode {
+		if o.VolumeAttachLimit != -1 && o.ReservedVolumeAttachments != -1 {
+			return fmt.Errorf("only one of --volume-attach-limit and --reserved-volume-attachments may be specified")
+		}
+	}
+
+	if o.MetricsCertFile != "" || o.MetricsKeyFile != "" {
+		if o.HttpEndpoint == "" {
+			return fmt.Errorf("--http-endpoint MUST be specififed when using the metrics server with HTTPS")
+		} else if o.MetricsCertFile == "" {
+			return fmt.Errorf("--metrics-cert-file MUST be specififed when using the metrics server with HTTPS")
+		} else if o.MetricsKeyFile == "" {
+			return fmt.Errorf("--metrics-key-file MUST be specififed when using the metrics server with HTTPS")
+		}
 	}
+
 	return nil
 }

pkg/driver/options_test.go

@@ -20,6 +20,12 @@ func TestAddFlags(t *testing.T) {
 	if err := f.Set("http-endpoint", ":8080"); err != nil {
 		t.Errorf("error setting http-endpoint: %v", err)
 	}
+	if err := f.Set("metrics-cert-file", "/https.crt"); err != nil {
+		t.Errorf("error setting metrics-cert-file: %v", err)
+	}
+	if err := f.Set("metrics-key-file", "/https.key"); err != nil {
+		t.Errorf("error setting metrics-key-file: %v", err)
+	}
 	if err := f.Set("enable-otel-tracing", "true"); err != nil {
 		t.Errorf("error setting enable-otel-tracing: %v", err)
 	}
@@ -89,7 +95,7 @@ func TestAddFlags(t *testing.T) {
 	}
 }
 
-func TestValidate(t *testing.T) {
+func TestValidateAttachmentLimits(t *testing.T) {
 	tests := []struct {
 		name                string
 		volumeAttachLimit   int64
@@ -127,6 +133,7 @@ func TestValidate(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			o := &Options{
+				Mode:                      NodeMode,
 				VolumeAttachLimit:         tt.volumeAttachLimit,
 				ReservedVolumeAttachments: tt.reservedAttachments,
 			}
@@ -142,3 +149,61 @@ func TestValidate(t *testing.T) {
 		})
 	}
 }
+
+func TestValidateMetricsHTTPS(t *testing.T) {
+	tests := []struct {
+		name            string
+		httpEndpoint    string
+		metricsCertFile string
+		metricsKeyFile  string
+		expectError     bool
+	}{
+		{
+			name: "disabled",
+		},
+		{
+			name:         "only http",
+			httpEndpoint: ":8080",
+		},
+		{
+			name:            "https with all",
+			httpEndpoint:    ":443",
+			metricsCertFile: "/https.crt",
+			metricsKeyFile:  "/https.key",
+		},
+		{
+			name:            "https with endpoint missing",
+			metricsCertFile: "/https.crt",
+			metricsKeyFile:  "/https.key",
+			expectError:     true,
+		},
+		{
+			name:           "https with cert missing",
+			httpEndpoint:   ":443",
+			metricsKeyFile: "/https.key",
+			expectError:    true,
+		},
+		{
+			name:            "https with key missing",
+			httpEndpoint:    ":443",
+			metricsCertFile: "/https.crt",
+			expectError:     true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			o := &Options{
+				Mode:            ControllerMode,
+				HttpEndpoint:    tt.httpEndpoint,
+				MetricsCertFile: tt.metricsCertFile,
+				MetricsKeyFile:  tt.metricsKeyFile,
+			}
+
+			err := o.Validate()
+			if (err != nil) != tt.expectError {
+				t.Errorf("Options.Validate() error = %v, wantErr %v", err, tt.expectError)
+			}
+		})
+	}
+}

pkg/metrics/metrics.go

@@ -72,7 +72,7 @@ func (m *metricRecorder) ObserveHistogram(name string, value float64, labels map
 }
 
 // InitializeMetricsHandler starts a new HTTP server to expose the metrics.
-func (m *metricRecorder) InitializeMetricsHandler(address, path string) {
+func (m *metricRecorder) InitializeMetricsHandler(address, path, certFile, keyFile string) {
 	if m == nil {
 		klog.InfoS("InitializeMetricsHandler: metric recorder is not initialized")
 		return
@@ -92,9 +92,16 @@ func (m *metricRecorder) InitializeMetricsHandler(address, path string) {
 	}
 
 	go func() {
+		var err error
 		klog.InfoS("Metric server listening", "address", address, "path", path)
 
-		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		if certFile != "" {
+			err = server.ListenAndServeTLS(certFile, keyFile)
+		} else {
+			err = server.ListenAndServe()
+		}
+
+		if err != nil && err != http.ErrServerClosed {
 			klog.ErrorS(err, "Failed to start metric server", "address", address, "path", path)
 			klog.FlushAndExit(klog.ExitFlushTimeout, 1)
 		}