How to use systemctl in Ubuntu 14.04

Question

I try to perform the following command in Ubuntu 14.04:

systemctl enable --now docker-cleanup-dangling-images.timer

I also tried it with sudo,

Answer 1

Ubuntu 14 and lower does not have "systemctl" Source: https://docs.docker.com/install/linux/linux-postinstall/#configure-docker-to-start-on-boot

Configure Docker to start on boot:

Most current Linux distributions (RHEL, CentOS, Fedora, Ubuntu 16.04 and higher) use systemd to manage which services start when the system boots. Ubuntu 14.10 and below use upstart.

1) systemd (Ubuntu 16 and above):

$ sudo systemctl enable docker

To disable this behavior, use disable instead.

$ sudo systemctl disable docker

2) upstart (Ubuntu 14 and below):

Docker is automatically configured to start on boot using upstart. To disable this behavior, use the following command:

$ echo manual | sudo tee /etc/init/docker.override
chkconfig

$ sudo chkconfig docker on

Done.