From 4091b6f6b4fe01876f8720332675f9c69be39541 Mon Sep 17 00:00:00 2001 From: Wim Date: Sun, 30 May 2021 00:25:30 +0200 Subject: Update vendor (#1498) --- .../labstack/echo/v4/middleware/proxy.go | 37 ++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'vendor/github.com/labstack/echo/v4/middleware/proxy.go') diff --git a/vendor/github.com/labstack/echo/v4/middleware/proxy.go b/vendor/github.com/labstack/echo/v4/middleware/proxy.go index 6f01f3a7..6cfd6731 100644 --- a/vendor/github.com/labstack/echo/v4/middleware/proxy.go +++ b/vendor/github.com/labstack/echo/v4/middleware/proxy.go @@ -1,13 +1,16 @@ package middleware import ( + "context" "fmt" "io" "math/rand" "net" "net/http" + "net/http/httputil" "net/url" "regexp" + "strings" "sync" "sync/atomic" "time" @@ -264,3 +267,37 @@ func ProxyWithConfig(config ProxyConfig) echo.MiddlewareFunc { } } } + +// StatusCodeContextCanceled is a custom HTTP status code for situations +// where a client unexpectedly closed the connection to the server. +// As there is no standard error code for "client closed connection", but +// various well-known HTTP clients and server implement this HTTP code we use +// 499 too instead of the more problematic 5xx, which does not allow to detect this situation +const StatusCodeContextCanceled = 499 + +func proxyHTTP(tgt *ProxyTarget, c echo.Context, config ProxyConfig) http.Handler { + proxy := httputil.NewSingleHostReverseProxy(tgt.URL) + proxy.ErrorHandler = func(resp http.ResponseWriter, req *http.Request, err error) { + desc := tgt.URL.String() + if tgt.Name != "" { + desc = fmt.Sprintf("%s(%s)", tgt.Name, tgt.URL.String()) + } + // If the client canceled the request (usually by closing the connection), we can report a + // client error (4xx) instead of a server error (5xx) to correctly identify the situation. + // The Go standard library (at of late 2020) wraps the exported, standard + // context.Canceled error with unexported garbage value requiring a substring check, see + // https://github.com/golang/go/blob/6965b01ea248cabb70c3749fd218b36089a21efb/src/net/net.go#L416-L430 + if err == context.Canceled || strings.Contains(err.Error(), "operation was canceled") { + httpError := echo.NewHTTPError(StatusCodeContextCanceled, fmt.Sprintf("client closed connection: %v", err)) + httpError.Internal = err + c.Set("_error", httpError) + } else { + httpError := echo.NewHTTPError(http.StatusBadGateway, fmt.Sprintf("remote %s unreachable, could not forward: %v", desc, err)) + httpError.Internal = err + c.Set("_error", httpError) + } + } + proxy.Transport = config.Transport + proxy.ModifyResponse = config.ModifyResponse + return proxy +} -- cgit v1.2.3