package handler import ( "fmt" "net/http" "strings" "github.com/tal-tech/go-zero/core/breaker" "github.com/tal-tech/go-zero/core/logx" "github.com/tal-tech/go-zero/core/stat" "github.com/tal-tech/go-zero/rest/httpx" "github.com/tal-tech/go-zero/rest/internal/security" ) const breakerSeparator = "://" func BreakerHandler(method, path string, metrics *stat.Metrics) func(http.Handler) http.Handler { brk := breaker.NewBreaker(breaker.WithName(strings.Join([]string{method, path}, breakerSeparator))) return func(next http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { promise, err := brk.Allow() if err != nil { metrics.AddDrop() logx.Errorf("[http] dropped, %s - %s - %s", r.RequestURI, httpx.GetRemoteAddr(r), r.UserAgent()) w.WriteHeader(http.StatusServiceUnavailable) return } cw := &security.WithCodeResponseWriter{Writer: w} defer func() { if cw.Code < http.StatusInternalServerError { promise.Accept() } else { promise.Reject(fmt.Sprintf("%d %s", cw.Code, http.StatusText(cw.Code))) } }() next.ServeHTTP(cw, r) }) } }