Just note for juniors

fast_copy_vm_to_new_vm.sh

# variables for run
NAME=cloudflare.com
SRCIP=1.1.1.1

# delete droplet
doctl compute droplet delete "${NAME}" --force

# create new droplet
doctl compute droplet create \
"${NAME}" \
--size 1gb \
--image debian-9-x64 \
--region fra1 \
--ssh-keys 98:72:1e:a6:f5:4c:92:b0:92:67:7c:f4:11:2c:19:e5 \
--enable-backups \
--wait

# go to machine
doctl compute ssh "${NAME}"

# install lxc
apt-get update -q
apt-get install -yq lxc xz-utils dnsmasq-base

# generate ssh key, install to ${SRCIP}
ssh-keygen
cat ~/.ssh/id_rsa.pub

# create lxc container
lxc-create -t download -n "${NAME}" -- -d debian -r stretch -a amd64 --no-validate

# rewrite configuration (networking)
cat << EOF > "/var/lib/lxc/${NAME}/config"
lxc.include = /usr/share/lxc/config/debian.common.conf
lxc.arch = linux64

lxc.rootfs = /var/lib/lxc/"${NAME}"/rootfs
lxc.rootfs.backend = dir
lxc.utsname = "${NAME}"

lxc.network.type = none
EOF


# sync remote machine to lxc container
screen rsync -vzaAX \
--progress \
--numeric-ids \
--delete \
--exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","etc/network/interfaces"} \
${SRCIP}:/ /var/lib/lxc/"${NAME}"/rootfs/

# start container
lxc-start -n "${NAME}"