Docker在stdin上组合和用户输入

有人能为Docker Compose的以下行为解释(并可能给出解决方法)吗?

给定以下文件:

文档文件

FROM alpine:3.8

COPY ./entrypoint.sh /entrypoint.sh

ENTRYPOINT [ "/entrypoint.sh" ]

入口点.sh

#!/bin/sh

until [ ! -z "$PLOP" ]; do
    echo -n 'enter value here: '
    read PLOP
done

echo "Good ... PLOP is $PLOP"

exit 1

docker-compose.yml公司

version: '3.7'

services:
  plop:
    tty: true
    stdin_open: true
    image: webofmars/plop:latest

输出如下:

1) ./entrypoint.sh

docker-stdin> ./entrypoint.sh
enter value here:
CASE1
Good ... PLOP is CASE1

似乎 好啊

2) docker-stdin> docker run -it webofmars/plop

enter value here: CASE2
Good ... PLOP is CASE2

似乎 好啊

3) docker-stdin> docker-compose run plop

enter value here: CASE3
Good ... PLOP is CASE3

似乎 好啊

4) docker-stdin> docker-compose up

Recreating docker-stdin_plop_1 ... done
Attaching to docker-stdin_plop_1 (last forever)

这看起来很奇怪而且 不好 用于我的用例

我错过什么了吗?