migrating from gitosis to gitolite

Migrating from gitosis to gitolite is pretty easy, because the basic design is the same. The differences are:

gitolite does not use a special repo for the configuration, pubkeys, etc. You can choose to version that directory but it is not required that you do so

Here's how we migrated my work repos:

login as the git user on the server, and get a bash shell prompt
disable gitosis by renaming /usr/bin/gitosis-serve to something else. This will prevent users from pushing anything while you do the backup, migration, etc.
For added safety, delete the post-update hook that gitosis-admin installed
```
rm ~/repositories/gitosis-admin.git/hooks/post-update
```
or at least rename it to .sample like all the other hooks hanging around, or edit it and comment out the line that calls gitosis-run-hook post-update.

If you do not do this, an accidental push to the gitosis-admin repo will mess up your ~/.ssh/authorized_keys file
take a backup of the ~/repositories directory
untar gitolite to some temporary directory and follow the instructions to install it. Some of the steps (like mkdir ~/repositories) will fail, but this is expected. Once this is done, cd to the $GL_ADMINDIR (by default ~/.gitolite)
```
cd ~/.gitolite
```
convert your gitosis config file:
```
src/conf-convert.pl < ~/.gitosis.conf > conf/gitolite.conf
```
be sure to check the file to make sure it converted correctly

copy the update hook to each of the existing repos

for i in ~/repositories/*.git
do
    cp src/update-hook.pl $i/hooks/update
done

copy the keys from gitosis's keydir

cp ~/repositories/gitosis-admin.git/gitosis-export/keydir/* keydir

Important: expand any multi-key filess you may have. See the "faq, tips, etc" document in the doc directory for an explanation of what multi-keys are, how gitosis does them and how gitolite does it differently.

You can split the keys manually, or use the following code (just copy-paste it into you xterm):
```
wc -l keydir/*.pub | grep -v total | grep -v -w 1 | while read a b
do
    i=1
    cat $b|while read l
    do
        echo "$l" > ${b%.pub}@$i.pub
        (( i++ ))
    done
    v $b $b.done
done
```
This will split each multi-key file (say "sitaram.pub") into individual files called "sitaram@1.pub", "sitaram@2.pub", etc., and rename the original to "sitaram.pub.done" so gitolite won't pick it up.

At this point you can rename the split parts more appropriately, like "sitaram@laptop.pub" and "sitaram@desktop.pub" or whatever. Please check the files to make sure this worked properly
edit ~/.ssh/authorized_keys and carefully remove all the lines containing "gitosis-serve", as well as the marker line that says "auto-generated by gitosis, DO NOT REMOVE", then save the file. If the file did not have any other keys and is now empty, don't worry -- save it anyway because gitolite expects the file to be present (even if it is empty).

At this point you're ready to "compile" the configuration. See the "admin" document for what to do, and how to check the outputs, etc.