Problem Description
When using Virtuozzo 7 (OpenVZ on CentOS 7), you are unable to start the docker service due to the following error:dockerd-current: level=fatal msg="Error starting daemon: Error initializing network controller: error obtaining controller instance: failed to create NAT chain: iptables failed: iptables --wait -t nat -N DOCKER: iptables v1.4.21: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)\nPerhaps iptables or your kernel needs to be upgraded.\n (exit status 3)"...
Problem Resolution
Run the following on your container to enable ip_tables kernel modules:sudo modprobe ip_tables sudo echo 'ip_tables' >> /etc/modules Then reboot the container and the issue should be resolved. Note that you'll probably want to set docker to load on boot with: systemctl enable docker
