Add tags for statsd in config

config/config.go

 	} `json:"network"`
 	Stats struct {
 		StatsD struct {
-			Enabled      bool             `json:"enabled"`
-			Address      TypeHostPort     `json:"address"`
-			MetricPrefix TypeMetricPrefix `json:"metric-prefix"`
+			Enabled      bool                `json:"enabled"`
+			Address      TypeHostPort        `json:"address"`
+			MetricPrefix TypeMetricPrefix    `json:"metric-prefix"`
+			TagFormat    TypeStatsdTagFormat `json:"tag-format"`
 		} `json:"statsd"`
 		Prometheus struct {
 			Enabled      bool             `json:"enabled"`
 			Enabled      bool   `toml:"enabled" json:"enabled,omitempty"`
 			Address      string `toml:"address" json:"address,omitempty"`
 			MetricPrefix string `toml:"metric-prefix" json:"metric-prefix,omitempty"`
+			TagFormat    string `toml:"tag-format" json:"tag-format,omitempty"`
 		} `toml:"statsd" json:"statsd,omitempty"`
 		Prometheus struct {
 			Enabled      bool   `toml:"enabled" json:"enabled,omitempty"`

config/type_statsd_tag_format.go

+package config
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	TypeStatsdTagFormatInfluxdb = "influxdb"
+	TypeStatsdTagFormatDatadog  = "datadog"
+	TypeStatsdTagFormatGraphite = "graphite"
+)
+
+type TypeStatsdTagFormat struct {
+	value string
+}
+
+func (c *TypeStatsdTagFormat) UnmarshalText(data []byte) error {
+	if len(data) == 0 {
+		return nil
+	}
+
+	text := strings.ToLower(string(data))
+
+	switch text {
+	case TypeStatsdTagFormatInfluxdb, TypeStatsdTagFormatDatadog, TypeStatsdTagFormatGraphite:
+		c.value = text
+	default:
+		return fmt.Errorf("incorrect tag format value: %s", string(data))
+	}
+
+	return nil
+}
+
+func (c TypeStatsdTagFormat) MarshalText() ([]byte, error) {
+	return []byte(c.value), nil
+}
+
+func (c *TypeStatsdTagFormat) String() string {
+	return c.value
+}
+
+func (c *TypeStatsdTagFormat) Value(defaultValue string) string {
+	if c.value == "" {
+		return defaultValue
+	}
+
+	return c.value
+}

config/type_statsd_tag_format_test.go

+package config_test
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeStatsdTagFormatTestStruct struct {
+	Value config.TypeStatsdTagFormat `json:"value"`
+}
+
+type TypeStatsdTagFormat struct {
+	suite.Suite
+}
+
+func (suite *TypeStatsdTagFormat) TestUnmarshalFail() {
+	testData := []string{
+		"p",
+		"ipv4",
+		"onlyipv4",
+		"ipv6prefer",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeStatsdTagFormatTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeStatsdTagFormat) TestUnmarshalOk() {
+	testData := []string{
+		config.TypeStatsdTagFormatDatadog,
+		config.TypeStatsdTagFormatInfluxdb,
+		config.TypeStatsdTagFormatGraphite,
+		strings.ToUpper(config.TypeStatsdTagFormatDatadog),
+		strings.ToUpper(config.TypeStatsdTagFormatInfluxdb),
+		strings.ToUpper(config.TypeStatsdTagFormatGraphite),
+		strings.ToLower(config.TypeStatsdTagFormatDatadog),
+		strings.ToLower(config.TypeStatsdTagFormatInfluxdb),
+		strings.ToLower(config.TypeStatsdTagFormatGraphite),
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeStatsdTagFormatTestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.EqualValues(t,
+				strings.ToLower(value),
+				testStruct.Value.Value(config.TypeStatsdTagFormatDatadog))
+		})
+	}
+}
+
+func (suite *TypeStatsdTagFormat) TestMarshalOk() {
+	testData := []string{
+		config.TypeStatsdTagFormatDatadog,
+		config.TypeStatsdTagFormatInfluxdb,
+		config.TypeStatsdTagFormatGraphite,
+		strings.ToUpper(config.TypeStatsdTagFormatDatadog),
+		strings.ToUpper(config.TypeStatsdTagFormatInfluxdb),
+		strings.ToUpper(config.TypeStatsdTagFormatGraphite),
+		strings.ToLower(config.TypeStatsdTagFormatDatadog),
+		strings.ToLower(config.TypeStatsdTagFormatInfluxdb),
+		strings.ToLower(config.TypeStatsdTagFormatGraphite),
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeStatsdTagFormatTestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, strings.ToLower(value), testStruct.Value.String())
+
+			marshalled, err := testStruct.Value.MarshalText()
+			assert.NoError(t, err)
+			assert.Equal(t, strings.ToLower(value), string(marshalled))
+		})
+	}
+}
+
+func (suite *TypeStatsdTagFormat) TestValue() {
+	testStruct := &typePreferIPTestStruct{}
+
+	suite.EqualValues(config.TypePreferIPPreferIPv4,
+		testStruct.Value.Value(config.TypePreferIPPreferIPv4))
+	suite.EqualValues(config.TypePreferIPPreferIPv6,
+		testStruct.Value.Value(config.TypePreferIPPreferIPv6))
+
+	data, err := json.Marshal(map[string]string{
+		"value": config.TypePreferOnlyIPv4,
+	})
+	suite.NoError(err)
+	suite.NoError(json.Unmarshal(data, testStruct))
+
+	suite.EqualValues(config.TypePreferOnlyIPv4,
+		testStruct.Value.Value(config.TypePreferOnlyIPv6))
+	suite.EqualValues(config.TypePreferOnlyIPv4,
+		testStruct.Value.Value(config.TypePreferIPPreferIPv6))
+}
+
+func TestTypeStatsdTagFormat(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeStatsdTagFormat{})
+}

example.config.toml

 address = "127.0.0.1:8888"
 # prefix of metric for statsd
 metric-prefix = "mtg"
+# tag format to use
+# supported values are 'datadog', 'influxdb' and 'graphite'
+# default format is graphite.
+tag-format = "datadog"
 
 # prometheus metrics integration.
 [stats.prometheus]