package env import ( "context" "os" "reflect" "strconv" "strings" "github.com/imdario/mergo" "github.com/unistack-org/micro/v3/config" ) var ( DefaultStructTag = "env" ) type envConfig struct { opts config.Options } func (c *envConfig) Options() config.Options { return c.opts } func (c *envConfig) Init(opts ...config.Option) error { for _, o := range opts { o(&c.opts) } return nil } func (c *envConfig) Load(ctx context.Context) error { for _, fn := range c.opts.BeforeLoad { if err := fn(ctx, c); err != nil && !c.opts.AllowFail { return err } } src, err := config.Zero(c.opts.Struct) if err == nil { err = c.fillValues(ctx, reflect.ValueOf(src)) } if err != nil && !c.opts.AllowFail { return err } if err = mergo.Merge(c.opts.Struct, src, mergo.WithOverride, mergo.WithTypeCheck, mergo.WithAppendSlice); err != nil && !c.opts.AllowFail { return err } for _, fn := range c.opts.AfterLoad { if err := fn(ctx, c); err != nil && !c.opts.AllowFail { return err } } return nil } func (c *envConfig) fillValue(ctx context.Context, value reflect.Value, val string) error { switch value.Kind() { case reflect.Map: t := value.Type() nvals := strings.FieldsFunc(val, func(c rune) bool { return c == ',' || c == ';' }) if value.IsNil() { value.Set(reflect.MakeMapWithSize(t, len(nvals))) } kt := t.Key() et := t.Elem() for _, nval := range nvals { kv := strings.FieldsFunc(nval, func(c rune) bool { return c == '=' }) mkey := reflect.Indirect(reflect.New(kt)) mval := reflect.Indirect(reflect.New(et)) if err := c.fillValue(ctx, mkey, kv[0]); err != nil { return err } if err := c.fillValue(ctx, mval, kv[1]); err != nil { return err } value.SetMapIndex(mkey, mval) } case reflect.Slice, reflect.Array: nvals := strings.FieldsFunc(val, func(c rune) bool { return c == ',' || c == ';' }) value.Set(reflect.MakeSlice(reflect.SliceOf(value.Type().Elem()), len(nvals), len(nvals))) for idx, nval := range nvals { nvalue := reflect.Indirect(reflect.New(value.Type().Elem())) if err := c.fillValue(ctx, nvalue, nval); err != nil { return err } value.Index(idx).Set(nvalue) } case reflect.Bool: v, err := strconv.ParseBool(val) if err != nil { return err } value.Set(reflect.ValueOf(v)) case reflect.String: value.Set(reflect.ValueOf(val)) case reflect.Float32: v, err := strconv.ParseFloat(val, 32) if err != nil { return err } value.Set(reflect.ValueOf(float32(v))) case reflect.Float64: v, err := strconv.ParseFloat(val, 64) if err != nil { return err } value.Set(reflect.ValueOf(float64(v))) case reflect.Int: v, err := strconv.ParseInt(val, 10, 0) if err != nil { return err } value.Set(reflect.ValueOf(int(v))) case reflect.Int8: v, err := strconv.ParseInt(val, 10, 8) if err != nil { return err } value.Set(reflect.ValueOf(v)) case reflect.Int16: v, err := strconv.ParseInt(val, 10, 16) if err != nil { return err } value.Set(reflect.ValueOf(int16(v))) case reflect.Int32: v, err := strconv.ParseInt(val, 10, 32) if err != nil { return err } value.Set(reflect.ValueOf(int32(v))) case reflect.Int64: v, err := strconv.ParseInt(val, 10, 64) if err != nil { return err } value.Set(reflect.ValueOf(int64(v))) case reflect.Uint: v, err := strconv.ParseUint(val, 10, 0) if err != nil { return err } value.Set(reflect.ValueOf(uint(v))) case reflect.Uint8: v, err := strconv.ParseUint(val, 10, 8) if err != nil { return err } value.Set(reflect.ValueOf(uint8(v))) case reflect.Uint16: v, err := strconv.ParseUint(val, 10, 16) if err != nil { return err } value.Set(reflect.ValueOf(uint16(v))) case reflect.Uint32: v, err := strconv.ParseUint(val, 10, 32) if err != nil { return err } value.Set(reflect.ValueOf(uint32(v))) case reflect.Uint64: v, err := strconv.ParseUint(val, 10, 64) if err != nil { return err } value.Set(reflect.ValueOf(uint64(v))) } return nil } func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error { var values reflect.Value if valueOf.Kind() == reflect.Ptr { values = valueOf.Elem() } else { values = valueOf } if values.Kind() == reflect.Invalid { return config.ErrInvalidStruct } fields := values.Type() for idx := 0; idx < fields.NumField(); idx++ { field := fields.Field(idx) value := values.Field(idx) if !value.CanSet() { continue } if len(field.PkgPath) != 0 { continue } switch value.Kind() { case reflect.Struct: value.Set(reflect.Indirect(reflect.New(value.Type()))) if err := c.fillValues(ctx, value); err != nil { return err } continue case reflect.Ptr: if value.IsNil() { if value.Type().Elem().Kind() != reflect.Struct { // nil pointer to a non-struct: leave it alone break } // nil pointer to struct: create a zero instance value.Set(reflect.New(value.Type().Elem())) } value = value.Elem() if err := c.fillValues(ctx, value); err != nil { return err } continue } tag, ok := field.Tag.Lookup(c.opts.StructTag) if !ok { return nil } val, ok := os.LookupEnv(tag) if !ok { continue } if err := c.fillValue(ctx, value, val); err != nil { return err } } return nil } func (c *envConfig) Save(ctx context.Context) error { for _, fn := range c.opts.BeforeSave { if err := fn(ctx, c); err != nil && !c.opts.AllowFail { return err } } for _, fn := range c.opts.AfterSave { if err := fn(ctx, c); err != nil && !c.opts.AllowFail { return err } } return nil } func (c *envConfig) String() string { return "env" } func NewConfig(opts ...config.Option) config.Config { options := config.NewOptions(opts...) if len(options.StructTag) == 0 { options.StructTag = DefaultStructTag } return &envConfig{opts: options} }