fail when endpoints point to same path locally (#5523)

cmd/endpoint.go

@@ -334,7 +334,7 @@ func CreateEndpoints(serverAddr string, args ...string) (string, EndpointList, S
 		return serverAddr, endpoints, setupType, fmt.Errorf("no endpoint found for this host")
 	}
 
-	// Check whether same path is not used in endpoints of a host.
+	// Check whether same path is not used in endpoints of a host on different port.
 	{
 		pathIPMap := make(map[string]set.StringSet)
 		for _, endpoint := range endpoints {
@@ -349,7 +349,6 @@ func CreateEndpoints(serverAddr string, args ...string) (string, EndpointList, S
 					err = fmt.Errorf("path '%s' can not be served by different port on same address", endpoint.Path)
 					return serverAddr, endpoints, setupType, err
 				}
-
 				pathIPMap[endpoint.Path] = IPSet.Union(hostIPSet)
 			} else {
 				pathIPMap[endpoint.Path] = hostIPSet
@@ -357,6 +356,21 @@ func CreateEndpoints(serverAddr string, args ...string) (string, EndpointList, S
 		}
 	}
 
+	// Check whether same path is used for more than 1 local endpoints.
+	{
+		localPathSet := set.CreateStringSet()
+		for _, endpoint := range endpoints {
+			if !endpoint.IsLocal {
+				continue
+			}
+			if localPathSet.Contains(endpoint.Path) {
+				err = fmt.Errorf("path '%s' cannot be served by different address on same server", endpoint.Path)
+				return serverAddr, endpoints, setupType, err
+			}
+			localPathSet.Add(endpoint.Path)
+		}
+	}
+
 	// Check whether serverAddrPort matches at least in one of port used in local endpoints.
 	{
 		if !localPortSet.Contains(serverAddrPort) {

cmd/endpoint_test.go

@@ -257,7 +257,7 @@ func TestCreateEndpoints(t *testing.T) {
 			Endpoint{URL: &url.URL{Path: "/d4"}, IsLocal: true},
 		}, XLSetupType, nil},
 		{":9001", []string{"http://10.0.0.1:9000/export", "http://10.0.0.2:9000/export", "http://" + nonLoopBackIP + ":9001/export", "http://10.0.0.2:9001/export"}, "", EndpointList{}, -1, fmt.Errorf("path '/export' can not be served by different port on same address")},
-
+		{":9000", []string{"http://127.0.0.1:9000/export", "http://" + nonLoopBackIP + ":9000/export", "http://10.0.0.1:9000/export", "http://10.0.0.2:9000/export"}, "", EndpointList{}, -1, fmt.Errorf("path '/export' cannot be served by different address on same server")},
 		{":9000", []string{"http://localhost/d1", "http://localhost/d2", "http://example.org/d3", "http://example.com/d4"}, "", EndpointList{}, -1, fmt.Errorf("'localhost' resolves to loopback address is not allowed for distributed XL")},
 
 		// DistXL type