Arch Linux

Dieter@be

Forum Fellow

From: Belgium

Registered: 2006-11-05

Posts: 2,002

Website

git repo with default /etc as one branch, current /etc as another

I would like to track my /etc in git, and more specifically how my /etc is different from the default /etc.
Of course, "default /etc" is different for each system, because different packages installed means different /etc.

Ideally, I would have one branch containing the default /etc for my system, where every time I upgrade or remove packages, it adapts this branch accordingly.
Then, my real /etc would be in a different branch that follows this branch, by maintaining a patchset on top of it (using git rebase). this would also make it easy to copy changes to another system, by merging or cherry-picking commits.
There is a program like this, etckeeper: http://kitenet.net/~joey/code/etckeeper/, but:
- it requires a package manager with hooks. and pacman won't have hooks in the short term (see https://wiki.archlinux.org/index.php/Us … man_Hooks)
- etckeeper is mostly focused on tracking your own /etc in git, not so much the default /etc.

If anyone has some ideas how to do this, tell me. (or who wants to improve hooks support in pacman
To experiment, I wrote a small script build-default-etc.sh that goes over all installed packages and copies all their files matching ^/etc from the package file (from your cache) into a tmp dir.
This represents sort of (see caveats in the code) the "default /etc for your system"

#!/bin/bash
# limitations:
# - does not work with packages not in your cache (i.e. installed from AUR)
# - only catches what's in /etc in the package file, not what is generated with postinstall hooks
tmpdir=$(mktemp -d)
cd $tmpdir
# generate a listing with lines like: zsh zsh-4.3.11-2
pkgs=$(pacman -Qi | awk '/^Name/ { pkg=$3}; /^Version/ { printf "%s %s-%s\n",pkg, pkg,$3}')
while read pkg pkg_ver
do
    # if I don't use ls, it seems to store the literal glob :s
    # (even with matching file, so independent of nullglob)
    pkgfile="$(ls /var/cache/pacman/pkg/$pkg_ver* 2>/dev/null)"
    if [ -z "$pkgfile" ]
    then
        echo "> $pkg_ver [skipping: not in package cache]"
    else
        # apparently tar thinks it's an error if it doesn't find anything
        # matching the wildcard, so we help it a bit..
        if pacman -Ql $pkg | grep -q ' /etc.*[^/]$'
        then
            echo "> $pkg_ver [extracting]"
            tar -xf $pkgfile --wildcards 'etc/*'
        else
            echo "> $pkg_ver [skipping: no files in /etc]"
        fi
    fi
done < <(echo "$pkgs")
echo $tmpdir

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< Daenyth> and he works prolifically
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