Fixed stripPrefix middleware is not applied to retried attempts

integration/fixtures/retry/strip_prefix.toml

@@ -0,0 +1,40 @@
+[global]
+  checkNewVersion = false
+  sendAnonymousUsage = false
+
+[log]
+  level = "DEBUG"
+
+[entryPoints]
+  [entryPoints.web]
+    address = ":8000"
+
+[api]
+  insecure = true
+
+[providers.file]
+  filename = "{{ .SelfFilename }}"
+
+## dynamic configuration ##
+
+[http.routers]
+  [http.routers.router1]
+    service = "service1"
+    middlewares = [ "retry", "strip-prefix" ]
+    rule = "PathPrefix(`/`)"
+
+[http.middlewares.retry.retry]
+  attempts = 3
+
+[http.middlewares.strip-prefix.stripPrefix]
+  prefixes = [ "/test" ]
+
+[http.services]
+  [http.services.service1]
+    [http.services.service1.loadBalancer]
+
+      [[http.services.service1.loadBalancer.servers]]
+        url = "http://{{ .WhoamiIP }}:8080"
+
+      [[http.services.service1.loadBalancer.servers]]
+        url = "http://{{ .WhoamiIP }}:80"

integration/retry_test.go

@@ -1,6 +1,7 @@
 package integration
 
 import (
+	"io"
 	"net/http"
 	"os"
 	"time"
@@ -86,3 +87,26 @@ func (s *RetrySuite) TestRetryWebsocket(c *check.C) {
 	c.Assert(err, checker.IsNil)
 	c.Assert(response.StatusCode, checker.Equals, http.StatusSwitchingProtocols)
 }
+
+func (s *RetrySuite) TestRetryWithStripPrefix(c *check.C) {
+	file := s.adaptFile(c, "fixtures/retry/strip_prefix.toml", struct{ WhoamiIP string }{s.whoamiIP})
+	defer os.Remove(file)
+
+	cmd, display := s.traefikCmd(withConfigFile(file))
+	defer display(c)
+	err := cmd.Start()
+	c.Assert(err, checker.IsNil)
+	defer s.killCmd(cmd)
+
+	err = try.GetRequest("http://127.0.0.1:8080/api/rawdata", 60*time.Second, try.BodyContains("PathPrefix(`/`)"))
+	c.Assert(err, checker.IsNil)
+
+	response, err := http.Get("http://127.0.0.1:8000/test")
+	c.Assert(err, checker.IsNil)
+
+	body, err := io.ReadAll(response.Body)
+	c.Assert(err, checker.IsNil)
+
+	c.Assert(string(body), checker.Contains, "GET / HTTP/1.1")
+	c.Assert(string(body), checker.Contains, "X-Forwarded-Prefix: /test")
+}

pkg/middlewares/retry/retry.go

@@ -97,7 +97,7 @@ func (r *retry) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		}
 		newCtx := httptrace.WithClientTrace(req.Context(), trace)
 
-		r.next.ServeHTTP(retryResponseWriter, req.WithContext(newCtx))
+		r.next.ServeHTTP(retryResponseWriter, req.Clone(newCtx))
 
 		if !retryResponseWriter.ShouldRetry() {
 			return nil