git-clone-www.txt

#!/bin/bash
#
# Creates a new www sandbox managed by git.
#
# Usage: git-clone-www [dirname]
#
# dirname defaults to "www-git".
#

DIRNAME=${1:-www-git}

NFS_REPO=/home/engshare/git/tfb

# Are we running on a machine that has a local shared copy of the git repo?
if [ -d /data/git/tfb ]; then
	# Yes. Reuse its objects directory.
	echo "Cloning the local host's shared www repository..."
	PARENT=/data/git/tfb
	SHARE=-s
else
	# Nope, copy the NFS server's objects locally so as not to be dog slow.
	echo "Copying from the shared www repository on the NFS server..."
	PARENT=$NFS_REPO
	SHARE=
fi

if [ ! -d $HOME/local ]; then
	echo "You don't seem to have a 'local' symlink in your home directory."
	echo "Fix that and try again."
	exit 1
fi

cd $HOME/local
if [ -d "$DIRNAME" ]; then
	echo "You already have a $DIRNAME directory; won't overwrite it."
	echo "Aborting."
	exit 1
fi

# We clone the shared repository here rather than running "git svn clone"
# because it's much, much more efficient. And the clone has some options:
#
# -n = Don't check out working copy yet.
# -s = Reference the origin's .git/objects directory rather than copying.
#      Saves gobs of disk space and makes the clone nearly instantaneous.
#      We don't do this if there's no local-disk shared repo.

git clone $SHARE -n "$PARENT" "$DIRNAME"

cd "$DIRNAME"

# If we're sharing a local repository's objects, use the NFS server as a
# fallback so stuff doesn't break if we use this repo from another host
# that doesn't have a /data/git/tfb directory.
ALTERNATES=.git/objects/info/alternates
if [ -s $ALTERNATES ]; then
	echo $NFS_REPO/.git/objects >> $ALTERNATES
fi

# We want to use the same remote branch name ("remotes/trunk") for git-svn
# and for fetches from the shared git repo, so set that up explicitly.
git config remote.origin.url "file://$PARENT/.git"
git config remote.origin.fetch refs/remotes/trunk:refs/remotes/trunk
git config --remove-section branch.master

# Enable the standard commit template
git config commit.template /home/engshare/admin/scripts/templates/git-commit-template.txt

# Enable recording of rebase conflict resolutions
git config rerere.enabled true

# Now fetch from the shared repo. This mostly just creates the new "trunk"
# branch since we already have the objects thanks to the initial "git clone".
git fetch origin

# Blow away the "origin/" branches created by "git clone" -- we don't need them.
rm -rf .git/refs/remotes/origin

# Now it's time to turn this plain old git repo into a git-svn repo. Really
# all we need is the svn-remote configuration (installed above) and a
# metadata file with some version information. git-svn is smart enough to
# rebuild the other stuff it needs.

echo ""
echo "Synchronizing with svn..."

git svn init -itrunk svn+ssh://tubbs/svnroot/tfb/trunk/www

# Now tweak the git-svn config a little bit so it's easier for someone to
# go add more "fetch" lines if they want to track svn-side branches in
# addition to trunk. This doesn't affect any of the existing history.
git config svn-remote.svn.url svn+ssh://tubbs/svnroot
git config svn-remote.svn.fetch tfb/trunk/www:refs/remotes/trunk

# Let git-svn update its mappings and fetch the latest revisions. This can
# spew lots of uninteresting output so suppress it.
git svn fetch > /dev/null

echo ""
echo "Checking out working copy..."

# We use git reset here because the git svn fetch might have advanced trunk
# to a newer revision than the master branch created by git clone.
git reset --hard trunk

if [ ! -d "$HOME/$DIRNAME" ]; then
	echo ""
	echo "Making home dir symlink: $HOME/$DIRNAME"
	ln -s "local/$DIRNAME" "$HOME/$DIRNAME"
else
	echo ""
	echo "$HOME/$DIRNAME already exists; leaving it alone."
fi

echo ""
echo "All done. To make this your new main sandbox directory, run"
echo ""
echo "    rm -rf ~/www"
echo "    ln -s ~/$DIRNAME ~/www"
echo ""