序
本文次要钻研一下 dubbo-go-proxy 的 remoteFilter
remoteFilter
dubbo-go-proxy/pkg/filter/remote/call.go
func Init() {extension.SetFilterFunc(constant.RemoteCallFilter, remoteFilterFunc())
}
func remoteFilterFunc() fc.FilterFunc {return New(defaultNewParams()).Do()}
func defaultNewParams() mockLevel {
mock := 1
mockStr := os.Getenv(constant.EnvMock)
if len(mockStr) > 0 {i, err := strconv.Atoi(mockStr)
if err == nil {mock = i}
}
return mockLevel(mock)
}
type mockLevel int8
const (
open = iota
close
all
)
// clientFilter is a filter for recover.
type clientFilter struct {level mockLevel}
// New create timeout filter.
func New(level mockLevel) filter.Filter {
if level < 0 || level > 2 {level = close}
return &clientFilter{level: level,}
}
clientFilter 往 extension 注册了名为
dgp.filters.remote_call
的 filter func;该 func 执行的是 Do 办法
Do
dubbo-go-proxy/pkg/filter/remote/call.go
func (f clientFilter) Do() fc.FilterFunc {return func(c fc.Context) {f.doRemoteCall(c.(*contexthttp.HttpContext))
}
}
func (f clientFilter) doRemoteCall(c *contexthttp.HttpContext) {api := c.GetAPI()
if (f.level == open && api.Mock) || (f.level == all) {
c.SourceResp = &filter.ErrResponse{Message: "mock success",}
c.Next()
return
}
typ := api.Method.IntegrationRequest.RequestType
cli, err := matchClient(typ)
if err != nil {
c.Err = err
return
}
resp, err := cli.Call(client.NewReq(c.Ctx, c.Request, *api))
if err != nil {logger.Errorf("[dubbo-go-proxy] client call err:%v!", err)
c.Err = err
return
}
logger.Debugf("[dubbo-go-proxy] client call resp:%v", resp)
c.SourceResp = resp
// response write in response filter.
c.Next()}
func matchClient(typ config.RequestType) (client.Client, error) {switch strings.ToLower(string(typ)) {case string(config.DubboRequest):
return dubbo.SingletonDubboClient(), nil
case string(config.HTTPRequest):
return clienthttp.SingletonHTTPClient(), nil
default:
return nil, errors.New("not support")
}
}
Do 办法执行的是 doRemoteCall,该办法辉县判断是否是 mock,如果是则返回 mock success;之后依据 RequestType 判断是否反对该申请类型并返回对应的 client,最初通过 cli.Call 执行申请
Client
dubbo-go-proxy/pkg/client/client.go
type Client interface {Init() error
Close() error
// Call invoke the downstream service.
Call(req *Request) (res interface{}, err error)
// MapParams mapping param, uri, query, body ...
MapParams(req *Request) (reqData interface{}, err error)
}
Client 接口定义了 Init、Close、Call、MapParams 办法,它有两个实现类,别离是 dubbo.Client 及 http.Client
小结
dubbo-go-proxy 的 clientFilter 往 extension 注册了名为 dgp.filters.remote_call
的 filter func;该 func 执行的是 Do 办法,该办法依据 RequestType 判断是否反对该申请类型并返回对应的 client,最初通过 cli.Call 执行申请。
doc
- dubbo-go-proxy