Manage Your Configs with vcsh
If you're anything like me (and don't you want to be?), you probably have more than one Linux or UNIX machine that you use on a regular basis. Perhaps you've got a laptop and a desktop. Or, maybe you've got a few servers on which you have shell accounts. Managing the configuration files for applications like mutt, Irssi and others isn't hard, but the administrative overhead just gets tedious, particularly when moving from one machine to another or setting up a new machine.
Some time ago, I started using Dropbox to manage and synchronize my
configuration files. What I'd done was create several folders in Dropbox, and
then when I'd set up a new machine, I'd install Dropbox, sync those folders
and create symlinks from the configs in those directories to the desired
configuration file in my home directory. As an example, I'd have a directory
called Dropbox/conf/mutt, with my .muttrc file inside that directory. Then,
I'd create a symlink like
worked, but it quickly got out of hand and became a major pain in the neck to
maintain. Not only did I have to get Dropbox working on Linux, including my
command-line-only server machines, but I also had to ensure that I made a bunch of
symlinks in just the right places to make everything work. The last straw was
when I got a little ARM-powered Linux machine and wanted to get my
configurations on it, and realized that there's no ARM binary for the
Dropbox sync dæmon. There had to be another way.
...and There Was Another Way
It turns out I'm not the only one who's struggled with this. vcsh developer Richard Hartmann also had this particular itch, except he came up with a way to scratch it: vcsh. vcsh is a script that wraps both git and mr into an easy-to-use tool for configuration file management.
So, by now, I bet you're asking, "Why are you using git for this? That sounds way too complicated." I thought something similar myself, until I actually started using it and digging in. Using vcsh has several advantages, once you get your head around the workflow. The first and major advantage to using vcsh is that all you really need is git, bash and mr—all of which are readily available (or can be built relatively easily)—so there's no proprietary dæmons or services required. Another advantage of using vcsh is that it leverages git's workflow. If you're used to checking in files with git, you'll feel right at home with vcsh. Also, because git is powering the whole system, you get the benefit of having your configuration files under version control, so if you accidentally make an edit to a file that breaks something, it's very easy to roll back using standard git commands.
Let's Get Started!
I'm going to assume you're on Ubuntu 12.04 LTS or higher for this, because it
makes installation easy. A simple
sudo apt-get install vcsh mr
install vcsh and its dependencies. If you're on another Linux distro, or some other
UNIX derivative, you may need to check out vcsh and mr, and then build git if
it's not packaged. I'm also going to assume you've got a working git server
installed on another machine, because vcsh really shines for helping keep your
configs synchronized between machines.
Once you've installed vcsh and its dependencies, it's time to start using vcsh. Let's take a fairly common config file that most everyone who's ever used a terminal has—the config file for vim. This file lives in your home directory, and it's called .vimrc. If you've used vim at all before, this file will be here. I'm going to show you how to get it checked into a git repository that is under vcsh's control.
First, run the following command to initialize vcsh's git repository for vim:
[email protected]:~$ vcsh init vim vcsh: info: attempting to create '/home/bill/.config/vcsh/repo.d' vcsh: info: attempting to create '/home/bill/.gitignore.d' Initialized empty Git repository in ↪/home/bill/.config/vcsh/repo.d/vim.git/
I like to think of the "fake git repos" that vcsh works with to be almost like chroots (if you're familiar with that concept), as it makes things easier to work with. You're going to "enter a chroot", in a way, by telling vcsh you want to work inside the fake git repo for vim. This is done with this command:
[email protected]:~$ vcsh enter vim
Now, you're going to add the file .vimrc to the repository you created above by running the command:
[email protected]:~$ git add .vimrc
You're using normal git here, but inside the environment managed by vcsh. This is a design feature of vcsh to make it function very similarly to git.
Now that your file's being tracked by the git repository inside vcsh, let's commit it by running the following git-like command:
[email protected]:~$ git commit -m 'Initial Commit' master (root-commit) bc84953 Initial Commit Committer: Bill Childers [email protected] 1 file changed, 2 insertions(+) create mode 100644 .vimrc
Now for the really cool part. Just like standard git, you can push your files to a remote repository. This lets you make them available to other machines with one command. Let's do that now. First, you'll add the remote server. (I assume you already have a server set up and have the proper accounts configured. You'll also need a bare git repo on that server.) For example:
[email protected]:~$ git remote add origin [email protected]:vim.git
Next, push your files to that remote server:
[email protected]:~$ git push -u origin master Counting objects: 3, done. Compressing objects: 100% (2/2), done. Writing objects: 100% (3/3), 272 bytes, done. Total 3 (delta 0), reused 0 (delta 0) To [email protected]:vim.git * new branch master -> master Branch master set up to track remote branch master from origin. [email protected]:~$ exit
exit line at the end. This exits the
"vcsh fake git repo". Now
your .vimrc file is checked in and copied to a remote server! If there are
other programs for which you'd like to check in configurations, like mutt, you
simply can create a new repo by running
vcsh init mutt, and then run through
the process all over again, but this time, check your files into the mutt
Move Your Configuration to Another Machine
To sync your configuration to another machine, you just need to install vcsh, git and mr, and then run a similar process as the steps above, except you'll do a git pull from your server, rather than a push. This is because you don't have the .vimrc file you want locally, and you want to get it from your remote git repository.
The commands to do this are:
[email protected]:~$ sudo apt-get install vcsh git mr [email protected]:~$ vcsh enter vim [email protected]:~$ git remote add origin [email protected]:vim.git [email protected]:~$ git pull -u origin master From gitserver:vim * branch master -> FETCH_HEAD [email protected]:~$ exit
Now you've got your checked-in .vimrc file on your second host! This process works, but it's a little clunky, and it can become unwieldy when you start spawning multiple repositories. Luckily, there's a tool for this, and it's called mr.
Wrapping It All Up with mr
If you plan on using multiple repositories with vcsh (and you should—I'm
tracking 13 repositories at the moment), getting a configuration set up
for mr is essential. What mr brings to the table is a way to manage all the
repositories you're tracking with vcsh. It allows you to enable and
disable repositories simply by adjusting one symlink per repository, and it
also gives you the ability to update all your repos simply by running one
Perhaps the best way to get started using mr is to clone the repo that the vcsh author provides. This is done with the following command:
[email protected]:~$ vcsh clone ↪git://github.com/RichiH/vcsh_mr_template.git mr Initialized empty Git repository in ↪/home/bill/.config/vcsh/repo.d/mr.git/ remote: Counting objects: 19, done. remote: Compressing objects: 100% (14/14), done. remote: Total 19 (delta 1), reused 15 (delta 0) Unpacking objects: 100% (19/19), done. From git://github.com/RichiH/vcsh_mr_template * new branch master -> origin/master
Now that you've got your mr repo cloned, you'll want to go in and edit the files to point to your setup. The control files for mr live in ~/.config/mr/available.d, so go to that directory:
[email protected]:~/.config/mr/available.d$ ls mr.vcsh zsh.vcsh
Rename the zsh.vcsh file to vim.vcsh, because you're working with vim, and change the repository path to point to your server:
[email protected]:~/.config/mr/available.d$ mv zsh.vcsh vim.vcsh [email protected]:~/.config/mr/available.d$ vi vim.vcsh [$HOME/.config/vcsh/repo.d/vim.git] checkout = vcsh clone [email protected]:vim.git vim
Also, edit the mr.vcsh file to point to your server as well:
[email protected]:~/.config/mr/available.d$ vi mr.vcsh [$HOME/.config/vcsh/repo.d/mr.git] checkout = vcsh clone [email protected]:mr.git mr
The mr tool relies on symlinks from the available.d directory to the config.d directory (much like Ubuntu's Apache configuration, if you're familiar with that). This is how mr determines which repositories to sync. Since you've created a vim repo, make a symlink to tell mr to sync the vim repo:
[email protected]:~/.config/mr/available.d$ cd ../config.d [email protected]:~/.config/mr/config.d$ ls -l total 0 lrwxrwxrwx 1 bill bill 22 Jun 11 18:14 mr.vcsh -> ↪../available.d/mr.vcsh [email protected]:~/.config/mr/config.d$ ln -s ↪../available.d/vim.vcsh vim.vcsh [email protected]:~/.config/mr/config.d$ ls -l total 0 lrwxrwxrwx 1 bill bill 22 Jun 11 18:14 mr.vcsh -> ↪../available.d/mr.vcsh lrwxrwxrwx 1 bill bill 23 Jun 11 20:51 vim.vcsh -> ↪../available.d/vim.vcsh
Now, set up mr to be able to sync to your git server:
[email protected]:~/.config/mr/config.d$ cd ../.. [email protected]:~/.config$ vcsh enter mr [email protected]:~/.config$ ls mr vcsh [email protected]:~/.config$ git add mr [email protected]:\~/.config$ git commit -m 'Initial Commit' [master fa4eb18] Initial Commit Committer: Bill Childers [[email protected]] 3 files changed, 4 insertions(+), 1 deletion(-) create mode 100644 .config/mr/available.d/vim.vcsh create mode 120000 .config/mr/config.d/vim.vcsh [email protected]:\~/.config$ git remote add origin [email protected]:mr.git fatal: remote origin already exists.
Oh no! Why does the remote origin exist already? It's because you cloned the repo from the author's repository. Remove it, then create your own:
[email protected]:~/.config$ git remote show origin [email protected]:~/.config$ git remote rm origin [email protected]:~/.config$ git remote add origin [email protected]:mr.git [email protected]:~/.config$ git push -u origin master Counting objects: 28, done. Compressing objects: 100% (21/21), done. Writing objects: 100% (28/28), 2.16 KiB, done. Total 28 (delta 2), reused 0 (delta 0) To [email protected]:mr.git * [new branch] master -> master Branch master set up to track remote branch master from origin. [email protected]:~/.config$ exit
That's it! However, now that mr is in the mix, all you need to do to set up a
new machine is do a
vcsh clone [email protected]:mr.git mr to clone your mr
repository, then do an
mr up, and that machine will have all your repos
vcsh is a very powerful shell tool, and one that takes some time to adapt your thought processes to. However, once you do it, it makes setting up a new machine (or account on a machine) a snap, and it also gives you a way to keep things in sync easily. It's saved me a lot of time in the past few months, and it's allowed me to recover quickly from a bad configuration change I've made. Check it out for yourself!
Setting up a Remote Git Repo
A quick note on setting up a remote git repo: you'll need to set up passwordless authentication using SSH keys (see Resources for more information). Once you have that going using a "git" user, you simply need to create a git repo as the git user. That's done easily enough, just run the command:
[email protected]:~$ git init --bare vim.git Initialized empty Git repository in /home/git/vim.git/
Your bare repo will be ready for your vcsh client to check in stuff!
vcsh Home Page: http://github.com/RichiH/vcsh
mr Home Page: http://joeyh.name/code/mr
vcsh Background Slides: https://raw.github.com/RichiH/talks/slides/2012/fosdem/vcsh/fosdem-2012-vcsh-talk.pdf
How to Set Up Your Own Git Server: http://tumblr.intranation.com/post/766290565/how-set-up-your-own-private-git-server-linux
Set Up Passwordless SSH Key-Based Authentication: http://askubuntu.com/questions/46930/how-can-i-set-up-password-less-ssh-login