The idea behind etckeeper is as simple as smart: Use a VCS to keep track of changes to config files in /etc/, providing you with a history, rollback options and much more.

It is astonishing, how simple an idea can be and how much trouble it can save. Keeping the whole /etc/ folder under version control is a simple, yet elegant solution to many problems with it. Mistyped something in the config? Screwed up something? It doesn’t matter anymore. Check out your latest changes and roll them back. Have forgotten why you changed that setting to this, and why it was important? Check for the proper commit and read your own commit message explaining your change (if you were so careful to write one).

Really, etckeeper is worth gold. You do not need etckeeperto keep your /etc/ under version control, but it certainly makes it easier, providing you with a common command line interface for multiple VCS. Currently, etckeeper supports hg (Mercurial), git, bzr (Bazaar) and darcs.

etckeeper will automatically tracks changes made during package installation/removal and snapshots the state of /etc/ once a day.

Installation

etckeeper will not ship a VCS with itself, you will have to install it yourself, before you can use it.

Here is an overview over the installation of various VCS using apt-get:

Bazaar:

sudo apt-get install bzr
# installs bzr
bzr whoami "Your name <your_email@example.com>"
# sets your credentials

Git

sudo apt-get install git-core
# installs the git client
git config --global user.name "Your Name Here"
# Sets the default name for git to use when you commit
git config --global user.email "your_email@example.com"
# Sets the default email for git to use when you commit

Mercurial

sudo apt-get install mercurial

After that, run

hg --version

If that gives you an old version, try adding ppa:mercurial-ppa/releases to your package sources and update.

You need to set proper credentials in ~/.hgrc:

[ui]
username = Your Name Here <your_email@example.com>

Getting etckeeper

Once you have set up your desired VCS, you can install etckeeper using apt:

apt-get install etckeeper

At last, open /etc/etckeeper/etckeeper.conf, it should start as follows:

# The VCS to use.
#VCS="hg"
#VCS="git"
VCS="bzr"
#VCS="darcs"

As you can see, by default bzr is used. comment this line with a # and uncomment one of the other lines to change the VCS used by etckeeper.

After that, commit your current state of /etc/ with

etckeeper commit "Initial commit"

And you are done.

Advanced usage

Since you are basically using a VCS (using git for example will initialize a .git/ - repository in /etc/, you can use all features of your VCS also for tracking. That means you can and should commit the changed files after each change and should explain your changes in the commit message. This can save much, much time in the future when you are trying to re-think what you have done and why.

You can also use other features of your VCS, such as branching. Want to try out a new configuration? Create a new branch (not using etckeeper, but using the VCS you are using with ètckeeper), make some changes, commit them and thoroughly test them, maybe even for some days. If it turns out those changes were good, merge the said branch into the master branch and keep them. Otherwise, just switch back to the master branch and delete the old branch (or maybe merge only some commits from the branch into master). This is not really important on a desktop pc, but can be quite handy when used on a server. A good scenario is when you are tweaking performance issues and set some variables for certain services to new values. You might want to monitor how that turns out for some days and then decide wether to keep those changes or not.

All in all, I have found etckeeper a very handy solution for keeping /etc/ under control. It a simple, yet smart way of doing this.

This concludes this article, I hope it was helpful to you. You can leave comments by filing an issue on GitHub.