How permanently kill dockerd?
dockerd is common Linux daemon, nothing more than that. You should disable it the way suitable for your OS, depending on system services manager used.
Here are some examples (docker service name may vary system to system). First command stops the service, second disables its launch on system start.
For systemd driven OS (e.g. Ubuntu 16.04, RHEL/CentOS 7, Arch Linux), that will be:
sudo systemctl stop dockersudo systemctl disable dockerFor docker installed via snap:
sudo snap stop dockersudo snap disable dockerFor relatively old Ubuntu (before 15.10), using Upstart service manager:
sudo service docker stopsudo sh -c 'echo manual > /etc/init/docker.override'For older CentOS6 and some others:
sudo service dockerd stopsudo chkconfig dockerd off et cetera
You should look for instructions on how to disable service for specific OS you're interested in