Bash

Add this line on your $HOME/.bashrc

source <(hostctl completion bash)

Zsh

Add this line on your $HOME/.zshrc

source <(hostctl completion zsh)

NOTE: If you are using oh-my-zsh this method won’t work. Check below.

Oh-My-Zsh

• First generate the plugin with auto completion code

hostctl completion zsh > $HOME/.oh-my-zsh/plugins/hostctl/_hostctl

• Add it to your plugin list in $HOME/.zshrc

plugins=(... hostctl)

• Check that this lines are present somewere in $HOME/.zshrc

autoload -U compinit
compinit