Docker:在 CMD 的 shell 脚本中运行 init 和 systemctl 时出错

Question

文件

# Use Centos7 or RHEL7 base image
FROM centos:7

# This steps are needed so that systemd works within container
#ENV container docker

RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/system/*.wants/*;\
rm -f /lib/systemd/system/local-fs.target.wants/*; \
rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
rm -f /lib/systemd/system/basic.target.wants/*;\
rm -f /lib/systemd/system/anaconda.target.wants/*;

COPY startup.sh /usr/local/bin/startup.sh
CMD ["/usr/sbin/init"]

启动文件

#!/bin/bash
systemctl restart autofs

现在，我可以毫无问题地运行以下命令

docker build -t mycentos
docker run -d --privileged --name mycentos mycentos
docker exec -it  mycentos /bin/bash
./usr/local/bin/startup.sh

我希望 startup.sh 自动运行，而不必进入容器并手动运行它

所以，我只是将/usr/sbin/init 滚动到 startup.sh 并更改了 Dockerfile CMD

CMD ["/usr/local/bin/startup.sh"]

和

startup.sh 现在是

#!/bin/bash
/usr/sbin/init
systemctl restart autofs

我收到错误

Couldn't find an alternative telinit implementation to spawn.
Failed to get D-Bus connection: Operation not permitted

知道如何让 startup.sh 工作吗？

PS 我记得在/usr/sbin/init 没有运行时看到了同样的错误信息，我试着运行 systemctl

编辑
我已经改变了startup.sh

#!/bin/bash
/usr/bin/systemctl restart autofs &
exec /usr/sbin/init

看起来 autofs 从未从“docker run”CMD 启动

$docker run --rm -itd --privileged --name mycentos mycentos
0c977e677897fc9a42bd3a4efe6742fbb14ed888a010cfee94c604436729db2d
$ docker exec -it mycentos /bin/bash
[root@0c977e677897 /]# systemctl status autofs
\u25cf autofs.service - Automounts filesystems on demand
   Loaded: loaded (/usr/lib/systemd/system/autofs.service; disabled; vendor preset: disabled)
   Active: inactive (dead)

Answer 1

由于您没有安装 autofs 以及第二件事，您没有在 docker 文件中启用它。您首先要在 Dockerfile 中启用它。

这是您的 Dockerfile 稍作修改，启动脚本与您更新的相同。

启动文件

 #!/bin/bash
/usr/bin/systemctl restart autofs &
exec /usr/sbin/init

文件

 FROM centos:7

# This steps are needed so that systemd works within container
#ENV container docker

RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/system/*.wants/*;\
rm -f /lib/systemd/system/local-fs.target.wants/*; \
rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
rm -f /lib/systemd/system/basic.target.wants/*;\
rm -f /lib/systemd/system/anaconda.target.wants/*;
RUN yum install -y autofs
COPY startup.sh /usr/local/bin/startup.sh
RUN chmod +x /usr/local/bin/startup.sh
RUN systemctl enable autofs
CMD ["/usr/local/bin/startup.sh"]

注意:这有时也需要为 systemctl 挂载 cgroup。

-v /sys/fs/cgroup:/sys/fs/cgroup:ro 

这里在 docker 容器中运行命令





有关更多信息，您可以查看此 GitHub。

https://github.com/whyistheinternetbroken/docker-centos7-nfs-client-autofs/blob/master/Dockerfile