config/default.go

@@ -7,7 +7,9 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/imdario/mergo"
+	mid "go.unistack.org/micro/v4/util/id"
 	rutil "go.unistack.org/micro/v4/util/reflect"
 	mtime "go.unistack.org/micro/v4/util/time"
 )
@@ -124,6 +126,20 @@ func fillValue(value reflect.Value, val string) error {
 		}
 		value.Set(reflect.ValueOf(v))
 	case reflect.String:
+		switch val {
+		case "micro:generate uuid":
+			uid, err := uuid.NewRandom()
+			if err != nil {
+				return err
+			}
+			val = uid.String()
+		case "micro:generate id":
+			uid, err := mid.New()
+			if err != nil {
+				return err
+			}
+			val = uid
+		}
 		value.Set(reflect.ValueOf(val))
 	case reflect.Float32:
 		v, err := strconv.ParseFloat(val, 32)

config/default_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"go.unistack.org/micro/v4/config"
+	mid "go.unistack.org/micro/v4/util/id"
 	mtime "go.unistack.org/micro/v4/util/time"
 )
 
@@ -18,6 +19,8 @@ type cfg struct {
 	DurationValue  time.Duration   `default:"10s"`
 	MDurationValue mtime.Duration  `default:"10s"`
 	MapValue       map[string]bool `default:"key1=true,key2=false"`
+	UUIDValue      string          `default:"micro:generate uuid"`
+	IDValue        string          `default:"micro:generate id"`
 }
 
 type cfgStructValue struct {
@@ -71,6 +74,18 @@ func TestDefault(t *testing.T) {
 	if len(conf.MapValue) != 2 {
 		t.Fatalf("map value invalid: %#+v\n", conf.MapValue)
 	}
+
+	if conf.UUIDValue == "" {
+		t.Fatalf("uuid value empty")
+	} else if len(conf.UUIDValue) != 36 {
+		t.Fatalf("uuid value invalid: %s", conf.UUIDValue)
+	}
+
+	if conf.IDValue == "" {
+		t.Fatalf("id value empty")
+	} else if len(conf.IDValue) != mid.DefaultSize {
+		t.Fatalf("id value invalid: %s", conf.IDValue)
+	}
 	_ = conf
 	// t.Logf("%#+v\n", conf)
 }

go.mod

@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	github.com/DATA-DOG/go-sqlmock v1.5.0
+	github.com/google/uuid v1.3.0
 	github.com/imdario/mergo v0.3.15
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5

go.sum

@@ -5,6 +5,8 @@ github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg
 github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/imdario/mergo v0.3.15 h1:M8XP7IuFNsqUx6VPK2P9OSmsYsI/YFaGil0uD21V3dM=
 github.com/imdario/mergo v0.3.15/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=