问题描述：在编写Dockerfile创建supervisor容器时，最后一条启动supervisor的命令不起作用 -> CMD ["supervisord","-c","/etc/supervisord.conf"]，但是进到容器内部执行supervisord -c /etc/supervisord.conf可以成功运行。
先贴出来Dockerfile文件代码
FROM python:latest
WORKDIR /root/
RUN mkdir /etc/supervisor
RUN mkdir -p /root/projects/logs/gunicorn/
RUN mkdir -p /root/projects/logs/celery/
RUN mkdir -p /root/projects/Sy_EvaluateJkApi/logs/
RUN echo "deb http://mirrors.aliyun.com/debian/ buster main non-free contrib" > /etc/apt/sources.list
RUN echo "deb-src http://mirrors.aliyun.com/debian/ buster main non-free contrib" >> /etc/apt/sources.list
RUN echo "deb http://mirrors.aliyun.com/debian-security buster/updates main" >> /etc/apt/sources.list
RUN echo "deb-src http://mirrors.aliyun.com/debian-security buster/updates main" >> /etc/apt/sources.list
RUN echo "deb http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib" >> /etc/apt/sources.list
RUN echo "deb-src http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib" >> /etc/apt/sources.list
RUN echo "deb http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib" >> /etc/apt/sources.list
RUN echo "deb-src http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib" >> /etc/apt/sources.list
RUN apt-get update -y
RUN apt-get install -y git lrzsz vim
RUN pip install supervisor -i https://mirrors.aliyun.com/pypi/simple/
RUN pip install gunicorn -i https://mirrors.aliyun.com/pypi/simple/
RUN pip install gevent -i https://mirrors.aliyun.com/pypi/simple/
RUN /usr/local/bin/echo_supervisord_conf > /etc/supervisord.conf
RUN echo "[include]">>/etc/supervisord.conf
RUN echo "files = /etc/supervisor/*.ini">>/etc/supervisord.conf
ADD sy.ini /etc/supervisor/sy.ini
ADD Sy_EvaluateJkApi /root/projects/Sy_EvaluateJkApi
RUN pip3 install -r /root/projects/Sy_EvaluateJkApi/requirements.txt -i https://mirrors.aliyun.com/pypi/simple/
EXPOSE 8800
CMD ["supervisord","-c","/etc/supervisord.conf"]
使用docker build -t system:test . 命令构建容器镜像没有异常，但是使用docker run -itd system:test运行容器就会显示容器不在运行。
解决方式：把CMD ["supervisord","-c","/etc/supervisord.conf"]命令改成CMD ["supervisord","-n","-c","/etc/supervisord.conf"]就可以成功运行了。supervisor里是这么写的-n/--nodaemon -- run in the foreground (same as 'nodaemon=true' in config file)，加了-n让supervisor在前台保持运行就可以了。