在Docker容器中运行Tomcat - 容器在启动时退出

Question

我正在学习Docker并尝试构建一个Dockerfile，它将使用docker-compose而不是docker来运行Tomcat。

Dockerfile如下：

# Base the image on tomcat
FROM tomcat:7.0.82-jre7

WORKDIR /usr/local/tomcat

# Install updates & commands
RUN apt-get update && apt-get install -y vim

# Add some pre-set files
COPY tomcat-users.xml /usr/local/tomcat/conf

# Run the Tomcat on port 8080
EXPOSE 8080

# Start tomcat
# CMD ["bin/startup.sh", "run"]

docker-compose.yml文件如下：

 version: '3'

services:
tomcat:
    image: tomcat:7.0
    build:
        context: ./
        dockerfile: Dockerfile
    ports:
        - 8888:8080
    container_name: tomcat7
    volumes:
        - ./tomcat7:/usr/local/tomcat:rw
    entrypoint: /bin/bash /usr/local/tomcat/bin/startup.sh
    tty: true

tomcat7 docker容器启动但处于退出模式。

知道如何让它运行吗？