My docker-compser - why does not work

Please clarify I’m a novice docker and ROS user.
I managed to run the ROS turtle simulator based on the following commands:

sudo docker run -it --rm --net turtle_network --name turtle-core ros:ros-tutorials roscore

sudo docker run -it --rm --net turtle_network --name turtlegui --env DISPLAY=$DISPLAY --env QT_X11_NO_MITSHM=1 --volume /tmp/.X11-unix:/tmp/.X11-unix --env ROS_HOSTNAME=talker2 --env ROS_MASTER_URI=http://turtle-core:11311 ros:ros-tutorials rosrun turtlesim turtlesim_node

and

sudo docker run -it --rm --net chef_network --name teleop --env ROS_HOSTNAME=teleop --env ROS_MASTER_URI=http://turtle-core:11311 ros:ros-tutorials rosrun turtlesim turtle_teleop_key

Running the simulator above works!

In the next step, I’m trying to automate the project using docker-compose base on configuration file below:

cat docker-compose.yml

version: '2'
networks:
  default:
    external:
      name: turtle_network



services:
  turtle-core:
    image: ros:ros-tutorials
    container_name: turtle-core
    command:
      - roscore

  turtlegui:
#    build: .
    image: ros:ros-tutorials
    container_name: turtlegui
    volumes:
      - /tmp/.X11-unix:/tmp/.X11-unix
    environment:
      - DISPLAY=$DISPLAY
      - QT_X11_NO_MITSHM=1
      - ROS_HOSTNAME=turtlegui
      - ROS_MASTER_URI=http://turtle-core:11311
    command: 
      - rosrun turtlesim turtlesim_node

Unfortunately it does not work. I Receives the message:

sudo docker-compose logs -f -t
Attaching to turtlegui, turtle-core
turtlegui | 2017-08-17T09:00:02.832915121Z /ros_entrypoint.sh: line 6: exec: rosrun turtlesim turtlesim_node: not found
turtlegui exited with code 127

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                        PORTS               NAMES
9e7b22cd445a        ros:ros-tutorials   "/ros_entrypoint.sh '"   39 minutes ago      Exited (127) 39 minutes ago                       turtlegui
e5a7ee071384        ros:ros-tutorials   "/ros_entrypoint.sh r"   40 minutes ago      Up 40 minutes                                     turtle-core

What error I commit?