My goal has been to keep my home directory in a version control system effectively. I have a number of constraints however. I want the system to be modular. I don't always need X related config files in my home directory. Sometimes I want just my zsh related files and my emacs related files. I have multiple machines I check email from, and on those want to keep my notmuch/offlineimap files in sync, but I don't need these on every machine I'm on, expecially since those configurations have more sensitive data. I played around with laysvn for a while, but it never really seemed comfortable. I more recently discovered that madduck had started a "vcs-home" website and mailing list, talking about doing what I'm trying to do.

I'm now going with madduck's idea of using git with detached work trees, so that I can have multiple git repositories all using $HOME as their $GIT_WORK_TREE. I have a script inspired by his vcsh script that will create a subshell where the GIT_DIR, GIT_WORK_TREE variables are set for me. I can do my git operations related to just one git repository in that shell, while still operating directly on my config files in $HOME, and avoiding any kind of nasty symlinking or hardlinking. Since I am usually using my script to allow me to quickly "move in" to a new host, I named my script "movein". It can be found here. Here's how I'll typically use it:

    stew@guppy:~$ movein init
    git server hostname? git.vireo.org
    path to remote repositories? [~/git] 
    Local repository directory? [~/.movein] 
    Location of .mrconfig file? [~/.mrconfig] 
    stew@guppy:~$ 

This is just run once. It asks me questions about how to setup the 'movein' environment. Now I should have a .moveinrc storing the answers I gave above, I have a stub of a .mrconfig, and an empty .movein directory. Next thing to do is to add some of my repositories. The one I typically add on all machines is my "shell" repository. It has a .bashrc/.zshrc, an .alias that both source and other zsh goodies I'll generally wish to be around:

    stew@guppy:~$ ls .zshrc
    ls: cannot access .zshrc: No such file or directory
    stew@guppy:~$ movein add shell
    Initialized empty Git repository in /home/stew/.movein/shell.git/
    remote: Counting objects: 42, done.
    remote: Compressing objects: 100% (39/39), done.
    remote: Total 42 (delta 18), reused 0 (delta 0)
    Unpacking objects: 100% (42/42), done.
    From ssh://git.vireo.org//home/stew/git/shell
     * [new branch]      master     -> origin/master
    stew@guppy:~$ ls .zshrc
    .zshrc

So what happened here is that the ssh://git.vireo.org/~/git/shell.git repository was cloned with GIT_WORK_TREE=~ and GIT_DIR=.movein/shell.git. My .zshrc (along with a bunch of other files) has appeared. Next perhaps I'll add my emacs config files:

    stew@guppy:~$ movein add emacs       
    Initialized empty Git repository in /home/stew/.movein/emacs.git/
    remote: Counting objects: 77, done.
    remote: Compressing objects: 100% (63/63), done.
    remote: Total 77 (delta 10), reused 0 (delta 0)
    Unpacking objects: 100% (77/77), done.
    From ssh://git.vireo.org//home/stew/git/emacs
     * [new branch]      emacs21    -> origin/emacs21
     * [new branch]      master     -> origin/master
    stew@guppy:~$ ls .emacs
    .emacs
    stew@guppy:~$ 

My remote repositry has a master branch, but also has an emacs21 branch, which I can use when checking out on older machines which don't yet have newer versions of emacs.

Let's say I have made changes to my .zshrc file, and I want to check them in. Since we are working with detached work trees, git can't immediately help us:

    stew@guppy:~$ git status
    fatal: Not a git repository (or any of the parent directories): .git

The movein script allows me to "login" to one of the repositories. It will create a subshell with GIT_WORK_TREE and GIT_DIR set. In that subshell, git operations operate as one might expect:

    stew@guppy:~ $ movein login shell
    stew@guppy:~ (shell:master>*) $ echo >> .zshrc
    stew@guppy:~ (shell:master>*) $ git add .zshrc                                       
    stew@guppy:~ (shell:master>*) $ git commit -m "adding a newline to the end of .zshrc"
    [master 81b7311] adding a newline to the end of .zshrc
     1 files changed, 1 insertions(+), 0 deletions(-)
    stew@guppy:~ (shell:master>*) $ git push
    Counting objects: 8, done.
    Delta compression using up to 2 threads.
    Compressing objects: 100% (6/6), done.
    Writing objects: 100% (6/6), 546 bytes, done.
    Total 6 (delta 4), reused 0 (delta 0)
    To ssh://git.vireo.org//home/stew/git/shell.git
       d24bf2d..81b7311  master -> master
    stew@guppy:~ (shell:master*) $ exit
    stew@guppy:~ $ 

If I want to create a brand new repository from files in my home directory. I can:

    stew@guppy:~ $ touch methere
    stew@guppy:~ $ touch mealsothere
    stew@guppy:~ $ movein new oohlala methere mealsothere
    Initialized empty Git repository in /home/stew/git/oohlala.git/
    Initialized empty Git repository in /home/stew/.movein/oohlala.git/
    [master (root-commit) 7abe5ba] initial checkin
     0 files changed, 0 insertions(+), 0 deletions(-)
     create mode 100644 mealsothere
     create mode 100644 methere
    Counting objects: 3, done.
    Delta compression using up to 2 threads.
    Compressing objects: 100% (2/2), done.
    Writing objects: 100% (3/3), 224 bytes, done.
    Total 3 (delta 0), reused 0 (delta 0)
    To ssh://git.vireo.org//home/stew/git/oohlala.git
     * [new branch]      master -> master

Above, the command movein new oohlala methere mealsothere says "create a new repository containing two files: methere, mealsothere". A bare repository is created on the remote machine, a repository is created in the .movein directory, the files are committed, and the new commit is pushed to the remote repository. New on some other machine, I could run movein add oohlala to get these two new files.

The movein script maintains a .mrconfig file, so that joeyh's mr tool can be used to manage the repositories in bulk. Commands like "mr update", "mr commit", "mr push" will act on all the known repositories. Here's an example:

    stew@guppy:~ $ cat .mrconfig
    [DEFAULT]
    include = cat /usr/share/mr/git-fake-bare

    [/home/stew/.movein/emacs.git]
    checkout = git_fake_bare_checkout 'ssh://git.vireo.org//home/stew/git/emacs.git' 'emacs.git' '../../'

    [/home/stew/.movein/shell.git]
    checkout = git_fake_bare_checkout 'ssh://git.vireo.org//home/stew/git/shell.git' 'shell.git' '../../'

    [/home/stew/.movein/oohlala.git]
    checkout = git_fake_bare_checkout 'ssh://git.vireo.org//home/stew/git/oohlala.git' 'oohlala.git' '../../'

    stew@guppy:~ $ mr update
    mr update: /home/stew//home/stew/.movein/emacs.git
    From ssh://git.vireo.org//home/stew/git/emacs
     * branch            master     -> FETCH_HEAD
    Already up-to-date.

    mr update: /home/stew//home/stew/.movein/oohlala.git
    From ssh://git.vireo.org//home/stew/git/oohlala
     * branch            master     -> FETCH_HEAD
    Already up-to-date.

    mr update: /home/stew//home/stew/.movein/shell.git
    From ssh://git.vireo.org//home/stew/git/shell
     * branch            master     -> FETCH_HEAD
    Already up-to-date.

    mr update: finished (3 ok)
    stew@guppy:~ $ mr update