Rockylinux with systemd

1) 下載一個 image

Info: https://hub.docker.com/r/rockylinux/rockylinux

podman pull docker.io/rockylinux/rockylinux

2) 建立行 systemd 的 Containerfile

Containerfile                # which contains instructions for building the image

FROM docker.io/rockylinux/rockylinux:8

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"]

3) 建立 Image

podman build --rm -t r8-systemd .

Opns:

• -t imageName                   # 會自動叫 localhost/imageName
• --rm                                 # Remove intermediate containers after a successful build (Default: true)
• --file, -f=Containerfile.txt   # Default: Containerfile

4) Run Container

docker run -dit \
  --privileged \
  --volume /sys/fs/cgroup:/sys/fs/cgroup:ro \
  --name mytest \
  localhost/r8-systemd

 * In order to run a container with systemd,
    you will need to mount the cgroups volumes from the host.

5) Custom Container

# exec - Run a process in a running container

podman exec -it mytest bash

dnf install epel-release
dnf install vim screen wget curl iproute procps-ng passwd
dnf install openssh-server rsyslog

6) sshd Service start failed

.. sshd[395]: fatal: linux_audit_write_entry failed: Operation not permitted
.. sshd[395]: pam_unix(sshd:session): session closed for user root
.. sshd[395]: fatal: linux_audit_write_entry failed: Operation not permitted
.. sshd[404]: fatal: mm_request_send: write: Broken pipe

原因: podman dropped the audit_write capability by default.

Fix:

podman run --cap-add AUDIT_WRITE \
-p 22000:22 --expose=22 -dit centos:7 \
/bin/bash -c "yum install -y openssh-server && ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' && /usr/sbin/sshd -Dd"