Merge branch v2.2 into v2.3

CHANGELOG.md

@@ -1,5 +1,14 @@
+## [v2.2.11](https://github.com/containous/traefik/tree/v2.2.11) (2020-09-07)
+[All Commits](https://github.com/containous/traefik/compare/v2.2.10...v2.2.11)
+
+**Bug fixes:**
+- **[middleware]** fix: header middleware response writer. ([#7252](https://github.com/containous/traefik/pull/7252) by [ldez](https://github.com/ldez))
+
+**Documentation:**
+- **[healthcheck]** Clarified hostname documentation for load balancer healthcheck ([#7254](https://github.com/containous/traefik/pull/7254) by [AndrewSav](https://github.com/AndrewSav))
+
 ## [v2.2.10](https://github.com/containous/traefik/tree/v2.2.10) (2020-09-04)
-[All Commits](https://github.com/containous/traefik/compare/v2.2.0...v2.2.10)
+[All Commits](https://github.com/containous/traefik/compare/v2.2.7...v2.2.10)
 
 **Bug fixes:**
 - **[acme]** Update go-acme/lego to v4.0.1 ([#7238](https://github.com/containous/traefik/pull/7238) by [ldez](https://github.com/ldez))

docs/content/routing/services/index.md

@@ -317,7 +317,7 @@ Below are the available options for the health check mechanism:
 
 - `path` is appended to the server URL to set the health check endpoint.
 - `scheme`, if defined, will replace the server URL `scheme` for the health check endpoint
-- `hostname`, if defined, will replace the server URL `hostname` for the health check endpoint.
+- `hostname`, if defined, will apply `Host` header `hostname` to the the health check request.
 - `port`, if defined, will replace the server URL `port` for the health check endpoint.
 - `interval` defines the frequency of the health check calls.
 - `timeout` defines the maximum duration Traefik will wait for a health check request before considering the server failed (unhealthy).

pkg/middlewares/headers/responsewriter.go

@@ -1,6 +1,9 @@
 package headers
 
 import (
+	"bufio"
+	"fmt"
+	"net"
 	"net/http"
 
 	"github.com/containous/traefik/v2/pkg/log"
@@ -73,3 +76,19 @@ func (w *responseModifier) Write(b []byte) (int, error) {
 
 	return w.w.Write(b)
 }
+
+// Hijack hijacks the connection.
+func (w *responseModifier) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	if h, ok := w.w.(http.Hijacker); ok {
+		return h.Hijack()
+	}
+
+	return nil, nil, fmt.Errorf("not a hijacker: %T", w.w)
+}
+
+// Flush sends any buffered data to the client.
+func (w *responseModifier) Flush() {
+	if flusher, ok := w.w.(http.Flusher); ok {
+		flusher.Flush()
+	}
+}