LXD apply autostart [true|false] to all containers and default profile.

lxc-autostart.sh

#!/bin/bash

#
# Apply autostart to all containers and default profile.
# - Especially handy if containers have their own autostart value.
# - Could be used for any config value with a tweek.
#

# ask
while true; do
    read -p "Apply autostart [true or false] to all containers? " autostart
    case $autostart in
        [true]* )  autostart=true  ; break;;
        [false]* ) autostart=false ; break;;
        * ) echo "Please answer true or false.";;
    esac
done

# apply to default profile
lxc profile set default boot.autostart "$autostart"

# update containers configs
for container in $(lxc list --format=csv -c n); do    
    lxc config set "$container" boot.autostart "$autostart"
done