add docker stats support

Signed-off-by: Victor Vieux <vieux@docker.com>

api/api.go

@@ -364,6 +364,7 @@ func createRouter(c *context, enableCors bool) *mux.Router {
 			"/containers/{name:.*}/json":      getContainerJSON,
 			"/containers/{name:.*}/top":       proxyContainer,
 			"/containers/{name:.*}/logs":      proxyContainer,
+			"/containers/{name:.*}/stats":     proxyContainer,
 			"/containers/{name:.*}/attach/ws": notImplementedHandler,
 			"/exec/{execid:.*}/json":          proxyContainer,
 		},

api/flusher.go

@@ -0,0 +1,40 @@
+package api
+
+import (
+	"io"
+	"net/http"
+	"sync"
+
+	"github.com/docker/docker/pkg/ioutils"
+)
+
+type WriteFlusher struct {
+	sync.Mutex
+	w       io.Writer
+	flusher http.Flusher
+}
+
+func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
+	wf.Lock()
+	defer wf.Unlock()
+	n, err = wf.w.Write(b)
+	wf.flusher.Flush()
+	return n, err
+}
+
+// Flush the stream immediately.
+func (wf *WriteFlusher) Flush() {
+	wf.Lock()
+	defer wf.Unlock()
+	wf.flusher.Flush()
+}
+
+func NewWriteFlusher(w io.Writer) *WriteFlusher {
+	var flusher http.Flusher
+	if f, ok := w.(http.Flusher); ok {
+		flusher = f
+	} else {
+		flusher = &ioutils.NopFlusher{}
+	}
+	return &WriteFlusher{w: w, flusher: flusher}
+}

api/utils.go

@@ -67,7 +67,7 @@ func proxy(tlsConfig *tls.Config, addr string, w http.ResponseWriter, r *http.Re
 
 	copyHeader(w.Header(), resp.Header)
 	w.WriteHeader(resp.StatusCode)
-	io.Copy(w, resp.Body)
+	io.Copy(NewWriteFlusher(w), resp.Body)
 
 	return nil
 }