Add metrics

config/config.go

@@ -21,6 +21,7 @@ type Config struct {
 	HTTPListenAddr      string `toml:"HTTPListenAddr"`
 	HTTPAccessLogEnable bool   `toml:"HTTPAccessLogEnable"`
 	LogLevel            string `toml:"LogLevel"`
+	MetricsEnable       bool   `toml:"MetricsEnable"`
 }
 
 type InvalidValueError struct {
@@ -89,6 +90,13 @@ func (c *Config) UpdateFromEnv() error {
 		}
 	}
 
+	if metricsEnable, found := os.LookupEnv("DOGTAMER_METRICSENABLE"); found {
+		switch strings.ToUpper(metricsEnable) {
+		case "TRUE", "YES", "ENABLE":
+			c.MetricsEnable = true
+		}
+	}
+
 	return c.Verify()
 }