fix: avoid race condition by not running exec/start twice

pkg/container/client.go

@@ -463,13 +463,6 @@ func (client dockerClient) ExecuteCommand(containerID t.ContainerID, command str
 		clog.Errorf("Failed to extract command exec logs: %v", attachErr)
 	}
 
-	// Run the exec
-	execStartCheck := types.ExecStartCheck{Detach: false, Tty: true}
-	err = client.api.ContainerExecStart(bg, exec.ID, execStartCheck)
-	if err != nil {
-		return false, err
-	}
-
 	var output string
 	if attachErr == nil {
 		defer response.Close()

pkg/container/client_test.go

@@ -282,15 +282,6 @@ var _ = Describe("the client", func() {
 						}),
 						ghttp.RespondWithJSONEncoded(http.StatusOK, types.IDResponse{ID: execID}),
 					),
-					// API.ContainerExecStart
-					ghttp.CombineHandlers(
-						ghttp.VerifyRequest("POST", HaveSuffix("exec/%v/start", execID)),
-						ghttp.VerifyJSONRepresenting(types.ExecStartCheck{
-							Detach: false,
-							Tty:    true,
-						}),
-						ghttp.RespondWith(http.StatusOK, nil),
-					),
 					// API.ContainerExecInspect
 					ghttp.CombineHandlers(
 						ghttp.VerifyRequest("GET", HaveSuffix("exec/ex-exec-id/json")),