Merge pull request #969 from dotcloud/fix_logs

- Remote API: Fix a bug which caused 'docker logs' to fail

api.go

@@ -816,6 +816,7 @@ func createRouter(srv *Server, logging bool) (*mux.Router, error) {
 			localFct := fct
 			f := func(w http.ResponseWriter, r *http.Request) {
 				utils.Debugf("Calling %s %s", localMethod, localRoute)
+
 				if logging {
 					log.Println(r.Method, r.RequestURI)
 				}
@@ -836,6 +837,7 @@ func createRouter(srv *Server, logging bool) (*mux.Router, error) {
 					w.WriteHeader(http.StatusNotFound)
 					return
 				}
+
 				if err := localFct(srv, version, w, r, mux.Vars(r)); err != nil {
 					httpError(w, err)
 				}

commands.go

@@ -1036,10 +1036,10 @@ func (cli *DockerCli) CmdLogs(args ...string) error {
 		return nil
 	}
 
-	if err := cli.stream("POST", "/containers/"+cmd.Arg(0)+"/attach?logs=1&stdout=1", nil, os.Stdout); err != nil {
+	if err := cli.hijack("POST", "/containers/"+cmd.Arg(0)+"/attach?logs=1&stdout=1", false, nil, os.Stdout); err != nil {
 		return err
 	}
-	if err := cli.stream("POST", "/containers/"+cmd.Arg(0)+"/attach?logs=1&stderr=1", nil, os.Stderr); err != nil {
+	if err := cli.hijack("POST", "/containers/"+cmd.Arg(0)+"/attach?logs=1&stderr=1", false, nil, os.Stderr); err != nil {
 		return err
 	}
 	return nil
@@ -1370,6 +1370,7 @@ func (cli *DockerCli) stream(method, path string, in io.Reader, out io.Writer) e
 		return err
 	}
 	defer resp.Body.Close()
+
 	if resp.StatusCode < 200 || resp.StatusCode >= 400 {
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {
@@ -1407,19 +1408,24 @@ func (cli *DockerCli) stream(method, path string, in io.Reader, out io.Writer) e
 }
 
 func (cli *DockerCli) hijack(method, path string, setRawTerminal bool, in *os.File, out io.Writer) error {
+
 	req, err := http.NewRequest(method, fmt.Sprintf("/v%g%s", APIVERSION, path), nil)
 	if err != nil {
 		return err
 	}
+	req.Header.Set("User-Agent", "Docker-Client/"+VERSION)
 	req.Header.Set("Content-Type", "plain/text")
+
 	dial, err := net.Dial(cli.proto, cli.addr)
 	if err != nil {
 		return err
 	}
 	clientconn := httputil.NewClientConn(dial, nil)
-	clientconn.Do(req)
 	defer clientconn.Close()
 
+	// Server hijacks the connection, error 'connection closed' expected
+	clientconn.Do(req)
+
 	rwc, br := clientconn.Hijack()
 	defer rwc.Close()
 

server.go

@@ -979,17 +979,17 @@ func (srv *Server) ContainerAttach(name string, logs, stream, stdin, stdout, std
 		if stdout {
 			cLog, err := container.ReadLog("stdout")
 			if err != nil {
-				utils.Debugf(err.Error())
+				utils.Debugf("Error reading logs (stdout): %s", err)
 			} else if _, err := io.Copy(out, cLog); err != nil {
-				utils.Debugf(err.Error())
+				utils.Debugf("Error streaming logs (stdout): %s", err)
 			}
 		}
 		if stderr {
 			cLog, err := container.ReadLog("stderr")
 			if err != nil {
-				utils.Debugf(err.Error())
+				utils.Debugf("Error reading logs (stderr): %s", err)
 			} else if _, err := io.Copy(out, cLog); err != nil {
-				utils.Debugf(err.Error())
+				utils.Debugf("Error streaming logs (stderr): %s", err)
 			}
 		}
 	}