update

add conditional compilation support
add multi core support

core/hy/mmdb.go

@@ -0,0 +1,49 @@
+package hy
+
+import (
+	"io"
+	"net/http"
+	"os"
+
+	"github.com/oschwald/geoip2-golang"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+)
+
+func downloadMMDB(filename string) error {
+	resp, err := http.Get(viper.GetString("mmdb-url"))
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	file, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	_, err = io.Copy(file, resp.Body)
+	return err
+}
+
+func loadMMDBReader(filename string) (*geoip2.Reader, error) {
+	if _, err := os.Stat(filename); err != nil {
+		if os.IsNotExist(err) {
+			logrus.Info("GeoLite2 database not found, downloading...")
+			if err := downloadMMDB(filename); err != nil {
+				return nil, err
+			}
+			logrus.WithFields(logrus.Fields{
+				"file": filename,
+			}).Info("GeoLite2 database downloaded")
+			return geoip2.Open(filename)
+		} else {
+			// some other error
+			return nil, err
+		}
+	} else {
+		// file exists, just open it
+		return geoip2.Open(filename)
+	}
+}