Arch Linux Mirroring Script

armir.sh

#!/bin/bash

# This script is distributed under the MIT license
# Copyright 2017 Tyler Dence

do_sync() {
	# Sleep if we need to backoff
	sleep "$1";

	mirror="$2";
	webroot="$3";

	# Verify that there's not another sync process going on.
	mkdir "/tmp/archsynclock" &>/dev/null || exit;

	# Grab lastsync/lastupdate file via http, as it's less overhead
	if [ ! -z "$mirrorhttp" ]; then
		remote_update="$(wget "$mirrorhttp/lastupdate" -qO-)"
		local_update="$(cat "$webroot/lastupdate")";

		if [ $remote_update -gt $local_update ]; then
			rsync -rtlvH --delete-after --delay-updates --safe-links "$2" "$webroot";
		else
			wget "$mirrorhttp/lastsync" -O "$webroot/lastsync"
			echo 'Nothing more to do!';
		fi
	else
		rsync -rtlvH --delete-after --delay-updates --safe-links "$2" "$webroot";
	fi;

	rmdir "/tmp/archsynclock";
}

log(){
	echo "$@";
	echo `date -u "+%Y-%m-%d %H:%M:%S UTC"`" [Arch Repo Sync] ""$@" >> /var/log/arch_sync.log;
}

mlog(){
	while read line; do
		log "$line";
	done;
}

webroot='/var/www/arlm.tyzoid.com/web/';
mirror='rsync://mirror.csclub.uwaterloo.ca/archlinux/';
mirrorhttp='http://mirror.csclub.uwaterloo.ca/archlinux/';
random_backoff=0;
foreground=0;
while getopts "hfrw:m:" opt; do
	case "$opt" in
		r) random_backoff=$((RANDOM/36)); ;;
		f) foreground=1; ;;
		m) mirror="$OPTARG";
		   mirrorhttp=''; ;;
		w) webroot="$OPTARG"; ;;
		h)
			echo "Arch Linux Reposatory Syncing";
			echo "Options:";
			echo "   -r                Apply a random backoff of up to 15minutes on the script";
			echo "   -f                Run the sync in the foreground (not recommended)";
			echo "   -m  <rsync url>   Use the mirror specified instead of the default. Must be an rsync url.";
			echo "   -w  <webroot>     Use the webroot specified instead of the default. This is the location files will be synced to.";
			echo "   -h                Show this help menu";
			exit;
	esac
done;

if [ "$foreground" -eq 1 ]; then
	echo "Foreground, backoff=$random_backoff";
	do_sync "$random_backoff" "$mirror" "$webroot" | mlog;
else
	echo "Background, backoff=$random_backoff";
	{ do_sync "$random_backoff" "$mirror" "$webroot" | mlog & disown; } &>/dev/null
fi;