initial working version

Signed-off-by: Johan Siebens <johan.siebens@gmail.com>

internal/util/id.go

@@ -0,0 +1,53 @@
+package util
+
+import (
+	"fmt"
+	"github.com/sony/sonyflake"
+	"net"
+	"os"
+	"strconv"
+	"time"
+)
+
+var sf *sonyflake.Sonyflake
+
+func init() {
+	sf = sonyflake.NewSonyflake(sonyflake.Settings{
+		MachineID: machineID(),
+		StartTime: time.Date(2022, 05, 01, 00, 0, 0, 0, time.UTC),
+	})
+	if sf == nil {
+		panic("unable to initialize sonyflake")
+	}
+}
+
+func machineID() func() (uint16, error) {
+	envMachineID := os.Getenv("IONSCALE_MACHINE_ID")
+	if len(envMachineID) != 0 {
+		return func() (uint16, error) {
+			id, err := strconv.ParseInt(envMachineID, 0, 16)
+			if err != nil {
+				return 0, err
+			}
+			return uint16(id), nil
+		}
+	}
+
+	envMachineIP := os.Getenv("IONSCALE_MACHINE_IP")
+	if len(envMachineIP) != 0 {
+		return func() (uint16, error) {
+			ip := net.ParseIP(envMachineIP).To4()
+			if len(ip) < 4 {
+				return 0, fmt.Errorf("invalid IP")
+			}
+			return uint16(ip[2])<<8 + uint16(ip[3]), nil
+		}
+	}
+
+	return nil
+}
+
+func NextID() uint64 {
+	id, _ := sf.NextID()
+	return id
+}