sync.sh

#! /bin/bash

# 2014-04-22, v1.0, pull, push, initial clone of projects
# 2014-04-26, v2.0, speed improvement, use hashtable to determine push/pull
#                   automatically pull new projects based on remote hashtable

# setting up new repo (note: we should automate this at some point):
# create local git repo in projects (~/projects/xxx_name)
# login remote, create git repo $remote/"$target".git
# local git remote add "$remote"/
# git push
# echo $target `git rev-parse HEAD` >> $HOME/.sync.hashtable.remote
# scp $HOME/.sync.hashtable.remote "$remote"


echo "setting up variables.."
remotehost="example.com"
remoteuser="user"
remoterepo="/home/$remoteuser/stash"

cd $HOME
if [ ! -d $HOME/projects ]; then
	echo "no projects folder found, creating projects folder.."
	mkdir $HOME/projects
fi

echo "downloading remote hashtable.."
mv -f $HOME/.sync.hashtable.remote $HOME/.sync.hashtable.remote.old
scp "$remoteuser"@"$remotehost":"$remoterepo"/.sync.hashtable.remote . || exit

echo "retriving project names.."
projects=( `cut -d" " -f 1 $HOME/.sync.hashtable.remote` )
echo "    ${projects[@]}"

if [ "$1" == "pull" ]; then
	echo "performing initial cloning for new projects.."
	cd $HOME/projects
	for target in "${projects[@]}"
	do
		if [ ! -d "$target" ]; then
			echo "directory not found, performing initial cloning.."
			git clone ssh://"$remoteuser"@"$remotehost""$remoterepo"/"$target".git "$target"
		fi
	done
fi

if [ ! -e $HOME/.sync.hashtable ]; then
	echo "new install presumed, copying remote hash to local.."
	cp $HOME/.sync.hashtable.remote $HOME/.sync.hashtable
fi

echo "verify sync base.."
if ! cmp -s "$HOME/.sync.hashtable" "$HOME/.sync.hashtable.remote"; then
	echo "hashtables don't match, aborting.."
    exit 1
fi

# note: commiting is fast, so we can do it for all even if there is nothing to
# commit. this removes the requirement for some complex checks and does not
# impede performance much. pushing on the other hand takes long, even if nothing
# is pushed.
if [ "$1" == "push" ]; then
	echo "commit local changes.."
	cd $HOME/projects
	for target in "${projects[@]}"
	do
		cd "$target"
		git add *
		git commit -am "sync"
		cd ..
	done
fi

echo "updateing local hashtable.."
rm -f $HOME/.sync.hashtable

cd $HOME/projects
for target in "${projects[@]}"
do
	cd "$target"
	echo "$target" `git rev-parse HEAD` >> $HOME/.sync.hashtable
	cd ..
done

echo "extracting changed project names from hashtable.."
cd $HOME
diffs=( `diff .sync.hashtable .sync.hashtable.remote | grep "<" | cut -d" " -sf 2` )
echo "    ${diffs[@]}"

cd $HOME/projects
for target in "${diffs[@]}"
do
	if [ "$1" == "push" ]; then
		echo "puishing $target"
		cd $target
		git push
		cd ..
	elif [ "$1" == "pull" ]; then
		cd $target
		git pull
		cd ..
	fi

done

if [ "$1" == "push" ]; then
	cp -f $HOME/.sync.hashtable $HOME/.sync.hashtable.remote
	scp $HOME/.sync.hashtable.remote "$remoteuser"@"$remotehost":"$remoterepo" || exit
fi

echo "all done, exiting.."