Poor man's frozen apt mirror - it still needs work to do an auto clean based on files not referenced

0-setup.sh

apt-get update
apt-get purge -y nano
apt-get install -y vim tmux fail2ban nginx apt-mirror lxc

# change nginx config:
# /etc/nginx/sites-enabled/default
systemctl restart nginx

# change apt-mirror config:
# /etc/apt/mirror.list
# /var/spool/apt-mirror/var/postmirror.sh
su - apt-mirror -c apt-mirror

lxc-attach -n client1
lxc-create -t download -n client1 -- --dist ubuntu --release xenial --arch amd64

root@client1:/# cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu xenial main universe
deb http://10.0.3.1/ubuntu xenial-updates-20170319 main universe

default

server {
	listen 80 default_server;
	listen [::]:80 default_server;

	root /var/www/html;

	index index.html index.htm index.nginx-debian.html;

	server_name _;

	location / {
		# First attempt to serve request as file, then
		# as directory, then fall back to displaying a 404.
		try_files $uri $uri/ =404;
	}

        gzip on;

        location /ubuntu {
                root /var/spool/apt-mirror/mirror/archive.ubuntu.com;
                autoindex on;
                allow 10.0.3.0/24;
                allow 127.0.0.1/32;
                deny all;
        }

}

mirror.list

############# config ##################
#
# set base_path    /var/spool/apt-mirror
#
# set mirror_path  $base_path/mirror
# set skel_path    $base_path/skel
# set var_path     $base_path/var
# set cleanscript $var_path/clean.sh
# set defaultarch  <running host architecture>
# set postmirror_script $var_path/postmirror.sh
# set run_postmirror 0
set nthreads     20
set _tilde 0
#
############# end config ##############

deb http://archive.ubuntu.com/ubuntu xenial-updates main universe

# NB:
# The poor man's frozen mirror *must not* use the clean script
# as it will invalidate older snapshots.
# TODO:
# Figure out a way to do the cleaning up of any files that are
# not present in any of the stored snapshots.
#clean http://archive.ubuntu.com/ubuntu

postmirror.sh

#!/bin/sh -e

## Anything in this file gets run AFTER the mirror has been run.
## Put your custom post mirror operations in here (like rsyncing the installer
## files and running clean.sh automatically)!

rsync -a -delete --delete-after /var/spool/apt-mirror/mirror/archive.ubuntu.com/ubuntu/dists/xenial-updates/ /var/spool/apt-mirror/mirror/archive.ubuntu.com/ubuntu/dists/xenial-updates-$(date +%Y%m%d)