启动sshd服务。

service sshd start

检查sshd服务是否已经启动

ps -e | grep sshd 

systemctl enable sshd.service
systemctl list-unit-files | grep sshd

sudo sed -e 's|^mirrorlist=|#mirrorlist=|g' \
         -e 's|^#baseurl=http://mirror.centos.org|baseurl=https://mirrors.tuna.tsinghua.edu.cn|g' \
         -i.bak \
         /etc/yum.repos.d/CentOS-*.repo

sudo yum makecache         

sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine
yum remove podman buildah                  

sudo yum install -y yum-utils
sudo yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo                  

sudo yum install docker-ce docker-ce-cli containerd.io    

sudo systemctl start docker

# Check what interface docker is using, e.g. 'docker0'
ip link show

# Check available firewalld zones, e.g. 'public'
sudo firewall-cmd --get-active-zones

# Check what zone the docker interface it bound to, most likely 'no zone' yet
sudo firewall-cmd --get-zone-of-interface=docker0

# So add the 'docker0' interface to the 'public' zone. Changes will be visible only after firewalld reload
sudo nmcli connection modify docker0 connection.zone public

# Masquerading allows for docker ingress and egress (this is the juicy bit)
sudo firewall-cmd --zone=public --add-masquerade --permanent
# Optional open required incomming ports (wasn't required in my tests)
# sudo firewall-cmd --zone=public --add-port=443/tcp
# Reload firewalld
sudo firewall-cmd --reload
# Reload dockerd
sudo systemctl restart docker

# Test ping and DNS works:
docker run busybox ping -c 1 172.16.0.1
docker run busybox cat /etc/resolv.conf
docker run busybox ping -c 1 yourhost.local