Unable to use Systemctl commands in centos Docker

Question

I tried to install httpd inside docker container and tried to restart the httpd via systemctl in docker. But I'm getting a exception like below

As per my analysis systemctl not enabled by default in docker base images, experts suggested to configure like below.

    FROM centos:7

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/*;
VOLUME [ “/sys/fs/cgroup” ]
CMD ["/usr/sbin/init"]

I tried the same but still no luck. Another option I tried using centos/systemd as my base image, But no luck. This is my sample docker file which I'm trying.

FROM centos:7
    
RUN  yum -y install httpd php php-mysql php-gd mariadb-server php-xml php-intl mysql weget

RUN systemctl restart httpd.service

RUN  systemctl enable httpd.service
RUN  systemctl start mariadb 

RUN systemctl enable mariadb 

# RUN  mysql -u root -p -u root

EXPOSE 80

Any one please advise me on this ? Any other possibilities to achieve the same in different way?

References:

Docker CentOS systemctl not permitted https://forums.docker.com/t/systemctl-status-is-not-working-in-my-docker-container/9075/2

Answer 1

You should assume systemd don't work in Docker and start your httpd service in your Dockerfile with :

CMD ["/usr/sbin/httpd","-D","FOREGROUND"]

If you have several services (like your web + database service here), best practise is to split services into several containers that communicate between them.