无效的顶级属性"；网络“U模式”；来自docker compose

我想在docker compose上使用网络模式：“主机”，但被拒绝

$ cat docker-compose.yml
version: "3.7"
services:
  hello:
    image: hello-world:latest
$ docker-compose up
Creating network "tmp_default" with the default driver
Creating tmp_hello_1 ... done
Attaching to tmp_hello_1
hello_1  |
hello_1  | Hello from Docker!
hello_1  | This message shows that your installation appears to be working correctly.
:
tmp_hello_1 exited with code 0

嗯。让我使用网络模式：“主机”

为什么！？这是官方的，不是吗？

---

网络模式不是顶级属性。写在服务下

version: "3.7"
services:
  hello:
    network_mode: "host"
    image: hello-world:latest

$ docker-compose -v
docker-compose version 1.24.1, build 4667896b
$ docker -v
Docker version 19.03.2, build 6a30dfca03
$  cat /etc/os-release
NAME="Ubuntu"
VERSION="19.04 (Disco Dingo)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 19.04"
VERSION_ID="19.04"

version: "3.7"
services:
  hello:
    network_mode: "host"
    image: hello-world:latest