Merge release-20210408.0-38-g14b7d775c (automated)

2 files changed, 285 insertions, 70 deletions

diff --git a/pkg/metric/metric.go b/pkg/metric/metric.go
index c9f9357de..2a2f0d611 100644
--- a/pkg/metric/metric.go
+++ b/pkg/metric/metric.go
@@ -38,7 +38,7 @@ var (
 )
 
 // Uint64Metric encapsulates a uint64 that represents some kind of metric to be
-// monitored.
+// monitored. We currently support metrics with at most one field.
 //
 // Metrics are not saved across save/restore and thus reset to zero on restore.
 //
@@ -46,6 +46,16 @@ var (
 type Uint64Metric struct {
 	// value is the actual value of the metric. It must be accessed atomically.
 	value uint64
+
+	// numFields is the number of metric fields. It is immutable once
+	// initialized.
+	numFields int
+
+	// mu protects the below fields.
+	mu sync.RWMutex `state:"nosave"`
+
+	// fields is the map of fields in the metric.
+	fields map[string]uint64
 }
 
 var (
@@ -97,8 +107,19 @@ type customUint64Metric struct {
 	// metadata describes the metric. It is immutable.
 	metadata *pb.MetricMetadata
 
-	// value returns the current value of the metric.
-	value func() uint64
+	// value returns the current value of the metric for the given set of
+	// fields. It takes a variadic number of field values as argument.
+	value func(fieldValues ...string) uint64
+}
+
+// Field contains the field name and allowed values for the metric which is
+// used in registration of the metric.
+type Field struct {
+	// name is the metric field name.
+	name string
+
+	// allowedValues is the list of allowed values for the field.
+	allowedValues []string
 }
 
 // RegisterCustomUint64Metric registers a metric with the given name.
@@ -109,7 +130,8 @@ type customUint64Metric struct {
 // Preconditions:
 // * name must be globally unique.
 // * Initialize/Disable have not been called.
-func RegisterCustomUint64Metric(name string, cumulative, sync bool, units pb.MetricMetadata_Units, description string, value func() uint64) error {
+// * value is expected to accept exactly len(fields) arguments.
+func RegisterCustomUint64Metric(name string, cumulative, sync bool, units pb.MetricMetadata_Units, description string, value func(...string) uint64, fields ...Field) error {
 	if initialized {
 		return ErrInitializationDone
 	}
@@ -129,13 +151,25 @@ func RegisterCustomUint64Metric(name string, cumulative, sync bool, units pb.Met
 		},
 		value: value,
 	}
+
+	// Metrics can exist without fields.
+	if len(fields) > 1 {
+		panic("Sentry metrics support at most one field")
+	}
+
+	for _, field := range fields {
+		allMetrics.m[name].metadata.Fields = append(allMetrics.m[name].metadata.Fields, &pb.MetricMetadata_Field{
+			FieldName:     field.name,
+			AllowedValues: field.allowedValues,
+		})
+	}
 	return nil
 }
 
-// MustRegisterCustomUint64Metric calls RegisterCustomUint64Metric and panics
-// if it returns an error.
-func MustRegisterCustomUint64Metric(name string, cumulative, sync bool, description string, value func() uint64) {
-	if err := RegisterCustomUint64Metric(name, cumulative, sync, pb.MetricMetadata_UNITS_NONE, description, value); err != nil {
+// MustRegisterCustomUint64Metric calls RegisterCustomUint64Metric for metrics
+// without fields and panics if it returns an error.
+func MustRegisterCustomUint64Metric(name string, cumulative, sync bool, description string, value func(...string) uint64, fields ...Field) {
+	if err := RegisterCustomUint64Metric(name, cumulative, sync, pb.MetricMetadata_UNITS_NONE, description, value, fields...); err != nil {
 		panic(fmt.Sprintf("Unable to register metric %q: %v", name, err))
 	}
 }
@@ -144,15 +178,24 @@ func MustRegisterCustomUint64Metric(name string, cumulative, sync bool, descript
 // name.
 //
 // Metrics must be statically defined (i.e., at init).
-func NewUint64Metric(name string, sync bool, units pb.MetricMetadata_Units, description string) (*Uint64Metric, error) {
-	var m Uint64Metric
-	return &m, RegisterCustomUint64Metric(name, true /* cumulative */, sync, units, description, m.Value)
+func NewUint64Metric(name string, sync bool, units pb.MetricMetadata_Units, description string, fields ...Field) (*Uint64Metric, error) {
+	m := Uint64Metric{
+		numFields: len(fields),
+	}
+
+	if m.numFields == 1 {
+		m.fields = make(map[string]uint64)
+		for _, fieldValue := range fields[0].allowedValues {
+			m.fields[fieldValue] = 0
+		}
+	}
+	return &m, RegisterCustomUint64Metric(name, true /* cumulative */, sync, units, description, m.Value, fields...)
 }
 
 // MustCreateNewUint64Metric calls NewUint64Metric and panics if it returns an
 // error.
-func MustCreateNewUint64Metric(name string, sync bool, description string) *Uint64Metric {
-	m, err := NewUint64Metric(name, sync, pb.MetricMetadata_UNITS_NONE, description)
+func MustCreateNewUint64Metric(name string, sync bool, description string, fields ...Field) *Uint64Metric {
+	m, err := NewUint64Metric(name, sync, pb.MetricMetadata_UNITS_NONE, description, fields...)
 	if err != nil {
 		panic(fmt.Sprintf("Unable to create metric %q: %v", name, err))
 	}
@@ -169,19 +212,56 @@ func MustCreateNewUint64NanosecondsMetric(name string, sync bool, description st
 	return m
 }
 
-// Value returns the current value of the metric.
-func (m *Uint64Metric) Value() uint64 {
-	return atomic.LoadUint64(&m.value)
+// Value returns the current value of the metric for the given set of fields.
+func (m *Uint64Metric) Value(fieldValues ...string) uint64 {
+	if m.numFields != len(fieldValues) {
+		panic(fmt.Sprintf("Number of fieldValues %d is not equal to the number of metric fields %d", len(fieldValues), m.numFields))
+	}
+
+	switch m.numFields {
+	case 0:
+		return atomic.LoadUint64(&m.value)
+	case 1:
+		m.mu.RLock()
+		defer m.mu.RUnlock()
+
+		fieldValue := fieldValues[0]
+		if _, ok := m.fields[fieldValue]; !ok {
+			panic(fmt.Sprintf("Metric does not allow to have field value %s", fieldValue))
+		}
+		return m.fields[fieldValue]
+	default:
+		panic("Sentry metrics do not support more than one field")
+	}
 }
 
-// Increment increments the metric by 1.
-func (m *Uint64Metric) Increment() {
-	atomic.AddUint64(&m.value, 1)
+// Increment increments the metric field by 1.
+func (m *Uint64Metric) Increment(fieldValues ...string) {
+	m.IncrementBy(1, fieldValues...)
 }
 
 // IncrementBy increments the metric by v.
-func (m *Uint64Metric) IncrementBy(v uint64) {
-	atomic.AddUint64(&m.value, v)
+func (m *Uint64Metric) IncrementBy(v uint64, fieldValues ...string) {
+	if m.numFields != len(fieldValues) {
+		panic(fmt.Sprintf("Number of fieldValues %d is not equal to the number of metric fields %d", len(fieldValues), m.numFields))
+	}
+
+	switch m.numFields {
+	case 0:
+		atomic.AddUint64(&m.value, v)
+		return
+	case 1:
+		fieldValue := fieldValues[0]
+		m.mu.Lock()
+		defer m.mu.Unlock()
+
+		if _, ok := m.fields[fieldValue]; !ok {
+			panic(fmt.Sprintf("Metric does not allow to have field value %s", fieldValue))
+		}
+		m.fields[fieldValue] += v
+	default:
+		panic("Sentry metrics do not support more than one field")
+	}
 }
 
 // metricSet holds named metrics.
@@ -199,14 +279,30 @@ func makeMetricSet() metricSet {
 // Values returns a snapshot of all values in m.
 func (m *metricSet) Values() metricValues {
 	vals := make(metricValues)
+
 	for k, v := range m.m {
-		vals[k] = v.value()
+		fields := v.metadata.GetFields()
+		switch len(fields) {
+		case 0:
+			vals[k] = v.value()
+		case 1:
+			values := fields[0].GetAllowedValues()
+			fieldsMap := make(map[string]uint64)
+			for _, fieldValue := range values {
+				fieldsMap[fieldValue] = v.value(fieldValue)
+			}
+			vals[k] = fieldsMap
+		default:
+			panic(fmt.Sprintf("Unsupported number of metric fields: %d", len(fields)))
+		}
 	}
 	return vals
 }
 
-// metricValues contains a copy of the values of all metrics.
-type metricValues map[string]uint64
+// metricValues contains a copy of the values of all metrics. It is a map
+// with key as metric name and value can be either uint64 or map[string]uint64
+// to support metrics with one field.
+type metricValues map[string]interface{}
 
 var (
 	// emitMu protects metricsAtLastEmit and ensures that all emitted
@@ -233,14 +329,37 @@ func EmitMetricUpdate() {
 	snapshot := allMetrics.Values()
 
 	m := pb.MetricUpdate{}
+	// On the first call metricsAtLastEmit will be empty. Include all
+	// metrics then.
 	for k, v := range snapshot {
-		// On the first call metricsAtLastEmit will be empty. Include
-		// all metrics then.
-		if prev, ok := metricsAtLastEmit[k]; !ok || prev != v {
+		prev, ok := metricsAtLastEmit[k]
+		switch t := v.(type) {
+		case uint64:
+			// Metric exists and value did not change.
+			if ok && prev.(uint64) == t {
+				continue
+			}
+
 			m.Metrics = append(m.Metrics, &pb.MetricValue{
 				Name:  k,
-				Value: &pb.MetricValue_Uint64Value{v},
+				Value: &pb.MetricValue_Uint64Value{t},
 			})
+		case map[string]uint64:
+			for fieldValue, metricValue := range t {
+				// Emit data on the first call only if the field
+				// value has been incremented. For all other
+				// calls, emit data if the field value has been
+				// changed from the previous emit.
+				if (!ok && metricValue == 0) || (ok && prev.(map[string]uint64)[fieldValue] == metricValue) {
+					continue
+				}
+
+				m.Metrics = append(m.Metrics, &pb.MetricValue{
+					Name:        k,
+					FieldValues: []string{fieldValue},
+					Value:       &pb.MetricValue_Uint64Value{metricValue},
+				})
+			}
 		}
 	}
 
diff --git a/pkg/metric/metric_go_proto/metric.pb.go b/pkg/metric/metric_go_proto/metric.pb.go
index 19eab6274..166e878c3 100644
--- a/pkg/metric/metric_go_proto/metric.pb.go
+++ b/pkg/metric/metric_go_proto/metric.pb.go
@@ -119,12 +119,13 @@ type MetricMetadata struct {
 	sizeCache     protoimpl.SizeCache
 	unknownFields protoimpl.UnknownFields
 
-	Name        string               `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
-	Description string               `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
-	Cumulative  bool                 `protobuf:"varint,3,opt,name=cumulative,proto3" json:"cumulative,omitempty"`
-	Sync        bool                 `protobuf:"varint,4,opt,name=sync,proto3" json:"sync,omitempty"`
-	Type        MetricMetadata_Type  `protobuf:"varint,5,opt,name=type,proto3,enum=gvisor.MetricMetadata_Type" json:"type,omitempty"`
-	Units       MetricMetadata_Units `protobuf:"varint,6,opt,name=units,proto3,enum=gvisor.MetricMetadata_Units" json:"units,omitempty"`
+	Name        string                  `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	Description string                  `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
+	Cumulative  bool                    `protobuf:"varint,3,opt,name=cumulative,proto3" json:"cumulative,omitempty"`
+	Sync        bool                    `protobuf:"varint,4,opt,name=sync,proto3" json:"sync,omitempty"`
+	Type        MetricMetadata_Type     `protobuf:"varint,5,opt,name=type,proto3,enum=gvisor.MetricMetadata_Type" json:"type,omitempty"`
+	Units       MetricMetadata_Units    `protobuf:"varint,6,opt,name=units,proto3,enum=gvisor.MetricMetadata_Units" json:"units,omitempty"`
+	Fields      []*MetricMetadata_Field `protobuf:"bytes,7,rep,name=fields,proto3" json:"fields,omitempty"`
 }
 
 func (x *MetricMetadata) Reset() {
@@ -201,6 +202,13 @@ func (x *MetricMetadata) GetUnits() MetricMetadata_Units {
 	return MetricMetadata_UNITS_NONE
 }
 
+func (x *MetricMetadata) GetFields() []*MetricMetadata_Field {
+	if x != nil {
+		return x.Fields
+	}
+	return nil
+}
+
 type MetricRegistration struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -256,7 +264,8 @@ type MetricValue struct {
 	Name string `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
 	// Types that are assignable to Value:
 	//	*MetricValue_Uint64Value
-	Value isMetricValue_Value `protobuf_oneof:"value"`
+	Value       isMetricValue_Value `protobuf_oneof:"value"`
+	FieldValues []string            `protobuf:"bytes,4,rep,name=field_values,json=fieldValues,proto3" json:"field_values,omitempty"`
 }
 
 func (x *MetricValue) Reset() {
@@ -312,6 +321,13 @@ func (x *MetricValue) GetUint64Value() uint64 {
 	return 0
 }
 
+func (x *MetricValue) GetFieldValues() []string {
+	if x != nil {
+		return x.FieldValues
+	}
+	return nil
+}
+
 type isMetricValue_Value interface {
 	isMetricValue_Value()
 }
@@ -369,12 +385,67 @@ func (x *MetricUpdate) GetMetrics() []*MetricValue {
 	return nil
 }
 
+type MetricMetadata_Field struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	FieldName     string   `protobuf:"bytes,1,opt,name=field_name,json=fieldName,proto3" json:"field_name,omitempty"`
+	AllowedValues []string `protobuf:"bytes,2,rep,name=allowed_values,json=allowedValues,proto3" json:"allowed_values,omitempty"`
+}
+
+func (x *MetricMetadata_Field) Reset() {
+	*x = MetricMetadata_Field{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_pkg_metric_metric_proto_msgTypes[4]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *MetricMetadata_Field) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*MetricMetadata_Field) ProtoMessage() {}
+
+func (x *MetricMetadata_Field) ProtoReflect() protoreflect.Message {
+	mi := &file_pkg_metric_metric_proto_msgTypes[4]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use MetricMetadata_Field.ProtoReflect.Descriptor instead.
+func (*MetricMetadata_Field) Descriptor() ([]byte, []int) {
+	return file_pkg_metric_metric_proto_rawDescGZIP(), []int{0, 0}
+}
+
+func (x *MetricMetadata_Field) GetFieldName() string {
+	if x != nil {
+		return x.FieldName
+	}
+	return ""
+}
+
+func (x *MetricMetadata_Field) GetAllowedValues() []string {
+	if x != nil {
+		return x.AllowedValues
+	}
+	return nil
+}
+
 var File_pkg_metric_metric_proto protoreflect.FileDescriptor
 
 var file_pkg_metric_metric_proto_rawDesc = []byte{
 	0x0a, 0x17, 0x70, 0x6b, 0x67, 0x2f, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x2f, 0x6d, 0x65, 0x74,
 	0x72, 0x69, 0x63, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x06, 0x67, 0x76, 0x69, 0x73, 0x6f,
-	0x72, 0x22, 0xa8, 0x02, 0x0a, 0x0e, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x4d, 0x65, 0x74, 0x61,
+	0x72, 0x22, 0xad, 0x03, 0x0a, 0x0e, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x4d, 0x65, 0x74, 0x61,
 	0x64, 0x61, 0x74, 0x61, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01,
 	0x28, 0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x20, 0x0a, 0x0b, 0x64, 0x65, 0x73, 0x63,
 	0x72, 0x69, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x0b, 0x64,
@@ -388,25 +459,36 @@ var file_pkg_metric_metric_proto_rawDesc = []byte{
 	0x32, 0x0a, 0x05, 0x75, 0x6e, 0x69, 0x74, 0x73, 0x18, 0x06, 0x20, 0x01, 0x28, 0x0e, 0x32, 0x1c,
 	0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f, 0x72, 0x2e, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x4d, 0x65,
 	0x74, 0x61, 0x64, 0x61, 0x74, 0x61, 0x2e, 0x55, 0x6e, 0x69, 0x74, 0x73, 0x52, 0x05, 0x75, 0x6e,
-	0x69, 0x74, 0x73, 0x22, 0x17, 0x0a, 0x04, 0x54, 0x79, 0x70, 0x65, 0x12, 0x0f, 0x0a, 0x0b, 0x54,
-	0x59, 0x50, 0x45, 0x5f, 0x55, 0x49, 0x4e, 0x54, 0x36, 0x34, 0x10, 0x00, 0x22, 0x2e, 0x0a, 0x05,
-	0x55, 0x6e, 0x69, 0x74, 0x73, 0x12, 0x0e, 0x0a, 0x0a, 0x55, 0x4e, 0x49, 0x54, 0x53, 0x5f, 0x4e,
-	0x4f, 0x4e, 0x45, 0x10, 0x00, 0x12, 0x15, 0x0a, 0x11, 0x55, 0x4e, 0x49, 0x54, 0x53, 0x5f, 0x4e,
-	0x41, 0x4e, 0x4f, 0x53, 0x45, 0x43, 0x4f, 0x4e, 0x44, 0x53, 0x10, 0x01, 0x22, 0x46, 0x0a, 0x12,
-	0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x52, 0x65, 0x67, 0x69, 0x73, 0x74, 0x72, 0x61, 0x74, 0x69,
-	0x6f, 0x6e, 0x12, 0x30, 0x0a, 0x07, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x18, 0x01, 0x20,
-	0x03, 0x28, 0x0b, 0x32, 0x16, 0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f, 0x72, 0x2e, 0x4d, 0x65, 0x74,
-	0x72, 0x69, 0x63, 0x4d, 0x65, 0x74, 0x61, 0x64, 0x61, 0x74, 0x61, 0x52, 0x07, 0x6d, 0x65, 0x74,
-	0x72, 0x69, 0x63, 0x73, 0x22, 0x4f, 0x0a, 0x0b, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x56, 0x61,
-	0x6c, 0x75, 0x65, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28,
-	0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x23, 0x0a, 0x0c, 0x75, 0x69, 0x6e, 0x74, 0x36,
-	0x34, 0x5f, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x18, 0x02, 0x20, 0x01, 0x28, 0x04, 0x48, 0x00, 0x52,
-	0x0b, 0x75, 0x69, 0x6e, 0x74, 0x36, 0x34, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x42, 0x07, 0x0a, 0x05,
-	0x76, 0x61, 0x6c, 0x75, 0x65, 0x22, 0x3d, 0x0a, 0x0c, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x55,
-	0x70, 0x64, 0x61, 0x74, 0x65, 0x12, 0x2d, 0x0a, 0x07, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73,
-	0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x13, 0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f, 0x72, 0x2e,
-	0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x52, 0x07, 0x6d, 0x65, 0x74,
-	0x72, 0x69, 0x63, 0x73, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x69, 0x74, 0x73, 0x12, 0x34, 0x0a, 0x06, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x73, 0x18, 0x07, 0x20,
+	0x03, 0x28, 0x0b, 0x32, 0x1c, 0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f, 0x72, 0x2e, 0x4d, 0x65, 0x74,
+	0x72, 0x69, 0x63, 0x4d, 0x65, 0x74, 0x61, 0x64, 0x61, 0x74, 0x61, 0x2e, 0x46, 0x69, 0x65, 0x6c,
+	0x64, 0x52, 0x06, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x73, 0x1a, 0x4d, 0x0a, 0x05, 0x46, 0x69, 0x65,
+	0x6c, 0x64, 0x12, 0x1d, 0x0a, 0x0a, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x5f, 0x6e, 0x61, 0x6d, 0x65,
+	0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x09, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x4e, 0x61, 0x6d,
+	0x65, 0x12, 0x25, 0x0a, 0x0e, 0x61, 0x6c, 0x6c, 0x6f, 0x77, 0x65, 0x64, 0x5f, 0x76, 0x61, 0x6c,
+	0x75, 0x65, 0x73, 0x18, 0x02, 0x20, 0x03, 0x28, 0x09, 0x52, 0x0d, 0x61, 0x6c, 0x6c, 0x6f, 0x77,
+	0x65, 0x64, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x73, 0x22, 0x17, 0x0a, 0x04, 0x54, 0x79, 0x70, 0x65,
+	0x12, 0x0f, 0x0a, 0x0b, 0x54, 0x59, 0x50, 0x45, 0x5f, 0x55, 0x49, 0x4e, 0x54, 0x36, 0x34, 0x10,
+	0x00, 0x22, 0x2e, 0x0a, 0x05, 0x55, 0x6e, 0x69, 0x74, 0x73, 0x12, 0x0e, 0x0a, 0x0a, 0x55, 0x4e,
+	0x49, 0x54, 0x53, 0x5f, 0x4e, 0x4f, 0x4e, 0x45, 0x10, 0x00, 0x12, 0x15, 0x0a, 0x11, 0x55, 0x4e,
+	0x49, 0x54, 0x53, 0x5f, 0x4e, 0x41, 0x4e, 0x4f, 0x53, 0x45, 0x43, 0x4f, 0x4e, 0x44, 0x53, 0x10,
+	0x01, 0x22, 0x46, 0x0a, 0x12, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x52, 0x65, 0x67, 0x69, 0x73,
+	0x74, 0x72, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x12, 0x30, 0x0a, 0x07, 0x6d, 0x65, 0x74, 0x72, 0x69,
+	0x63, 0x73, 0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x16, 0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f,
+	0x72, 0x2e, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x4d, 0x65, 0x74, 0x61, 0x64, 0x61, 0x74, 0x61,
+	0x52, 0x07, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x22, 0x72, 0x0a, 0x0b, 0x4d, 0x65, 0x74,
+	0x72, 0x69, 0x63, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65,
+	0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x23, 0x0a, 0x0c,
+	0x75, 0x69, 0x6e, 0x74, 0x36, 0x34, 0x5f, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x18, 0x02, 0x20, 0x01,
+	0x28, 0x04, 0x48, 0x00, 0x52, 0x0b, 0x75, 0x69, 0x6e, 0x74, 0x36, 0x34, 0x56, 0x61, 0x6c, 0x75,
+	0x65, 0x12, 0x21, 0x0a, 0x0c, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x5f, 0x76, 0x61, 0x6c, 0x75, 0x65,
+	0x73, 0x18, 0x04, 0x20, 0x03, 0x28, 0x09, 0x52, 0x0b, 0x66, 0x69, 0x65, 0x6c, 0x64, 0x56, 0x61,
+	0x6c, 0x75, 0x65, 0x73, 0x42, 0x07, 0x0a, 0x05, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x22, 0x3d, 0x0a,
+	0x0c, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x55, 0x70, 0x64, 0x61, 0x74, 0x65, 0x12, 0x2d, 0x0a,
+	0x07, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x13,
+	0x2e, 0x67, 0x76, 0x69, 0x73, 0x6f, 0x72, 0x2e, 0x4d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x56, 0x61,
+	0x6c, 0x75, 0x65, 0x52, 0x07, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x62, 0x06, 0x70, 0x72,
+	0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -422,25 +504,27 @@ func file_pkg_metric_metric_proto_rawDescGZIP() []byte {
 }
 
 var file_pkg_metric_metric_proto_enumTypes = make([]protoimpl.EnumInfo, 2)
-var file_pkg_metric_metric_proto_msgTypes = make([]protoimpl.MessageInfo, 4)
+var file_pkg_metric_metric_proto_msgTypes = make([]protoimpl.MessageInfo, 5)
 var file_pkg_metric_metric_proto_goTypes = []interface{}{
-	(MetricMetadata_Type)(0),   // 0: gvisor.MetricMetadata.Type
-	(MetricMetadata_Units)(0),  // 1: gvisor.MetricMetadata.Units
-	(*MetricMetadata)(nil),     // 2: gvisor.MetricMetadata
-	(*MetricRegistration)(nil), // 3: gvisor.MetricRegistration
-	(*MetricValue)(nil),        // 4: gvisor.MetricValue
-	(*MetricUpdate)(nil),       // 5: gvisor.MetricUpdate
+	(MetricMetadata_Type)(0),     // 0: gvisor.MetricMetadata.Type
+	(MetricMetadata_Units)(0),    // 1: gvisor.MetricMetadata.Units
+	(*MetricMetadata)(nil),       // 2: gvisor.MetricMetadata
+	(*MetricRegistration)(nil),   // 3: gvisor.MetricRegistration
+	(*MetricValue)(nil),          // 4: gvisor.MetricValue
+	(*MetricUpdate)(nil),         // 5: gvisor.MetricUpdate
+	(*MetricMetadata_Field)(nil), // 6: gvisor.MetricMetadata.Field
 }
 var file_pkg_metric_metric_proto_depIdxs = []int32{
 	0, // 0: gvisor.MetricMetadata.type:type_name -> gvisor.MetricMetadata.Type
 	1, // 1: gvisor.MetricMetadata.units:type_name -> gvisor.MetricMetadata.Units
-	2, // 2: gvisor.MetricRegistration.metrics:type_name -> gvisor.MetricMetadata
-	4, // 3: gvisor.MetricUpdate.metrics:type_name -> gvisor.MetricValue
-	4, // [4:4] is the sub-list for method output_type
-	4, // [4:4] is the sub-list for method input_type
-	4, // [4:4] is the sub-list for extension type_name
-	4, // [4:4] is the sub-list for extension extendee
-	0, // [0:4] is the sub-list for field type_name
+	6, // 2: gvisor.MetricMetadata.fields:type_name -> gvisor.MetricMetadata.Field
+	2, // 3: gvisor.MetricRegistration.metrics:type_name -> gvisor.MetricMetadata
+	4, // 4: gvisor.MetricUpdate.metrics:type_name -> gvisor.MetricValue
+	5, // [5:5] is the sub-list for method output_type
+	5, // [5:5] is the sub-list for method input_type
+	5, // [5:5] is the sub-list for extension type_name
+	5, // [5:5] is the sub-list for extension extendee
+	0, // [0:5] is the sub-list for field type_name
 }
 
 func init() { file_pkg_metric_metric_proto_init() }
@@ -497,6 +581,18 @@ func file_pkg_metric_metric_proto_init() {
 				return nil
 			}
 		}
+		file_pkg_metric_metric_proto_msgTypes[4].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*MetricMetadata_Field); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
 	}
 	file_pkg_metric_metric_proto_msgTypes[2].OneofWrappers = []interface{}{
 		(*MetricValue_Uint64Value)(nil),
@@ -507,7 +603,7 @@ func file_pkg_metric_metric_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_pkg_metric_metric_proto_rawDesc,
 			NumEnums:      2,
-			NumMessages:   4,
+			NumMessages:   5,
 			NumExtensions: 0,
 			NumServices:   0,
 		},