UConf

UConf is a small tool aiming to provide simple handling of configuration files for an heterogeneous computer set.

Its key concepts are:

• Abstract host-specific config to common features (server, relay, ...)
• Host-specific configuration may range from a single-line change to a whole file rewrite
• Configuration files are modified in place, not in the source - versionned - repository.

In other words, it provides the following features:

• Map each host to a set of categories (e.g laptop, server, dev, remote, ...)
• For each category (or combination thereof), list the files to install and their destinations
• For each file, conditionnally include some parts depending on the active categories

Usage

Configuration

First, create the folder structure:

$ cd ~/conf
$ mkdir .uconf
$ touch .uconf/config

Then, set a few settings:

# .uconf/config

[core]
# Install files to my home folder
target = ~/

[categories]
# The host names "myhostname" belongs to the 'shell' and 'x11' categories
myhostname: shell x11

[files]
# Hosts in the 'shell' category should install
# the 'shell/gitconfig' and 'ssh/config' files
shell: shell/gitconfig ssh/config

# Hosts in the 'shell' but not the 'work' category should install
# our authorized_keys
shell && !work: ssh/authorized_keys

[actions]
# Files located in ~/conf/ssh are parsed and written to ~/.ssh/
ssh/* = parse destdir=".ssh/"

# shell/gitconfig goes to ~/.gitconfig
shell/gitconfig = parse destdir="~/.gitconfig"

Files

The heart of uconf is its file processing engine.

On the surface, it is a simple preprocessor that will parse files based on the categories defined in the .uconf/config file.

In other words, if the file shell/gitconfig contains:

[user]
#@if work
  name = Raphaël Barrois
  email = raphael.barrois@example.org
#@else
  name = Xelnor
  email = raphael.barrois@polytechnique.org
#@endif

And is build on the myhostname from the above example, the output will be:

# ~/.gitconfig
[user]
  name = Xelnor
  email = raphael.barrois@polytechnique.org

Commands

Once your configuration folder is set up, basic commands will be:

$ cd ~/conf
$ uconf make
Building file shell/gitconfig (FileProcessingAction)
Building file ssh/config (FileProcessingAction)
Building file ssh/authorized_keys (FileProcessingAction)

If you have modified a file, just backport its changes:

$ cd ~/conf
$ uconf back shell/gitconfig
Backporting file shell/gitconfig (FileProcessingAction)

This will update the source file (~/conf/shell/gitconfig in this example) to incorporate the changes from the destination file (here, ~/.gitconfig).

This works even if the file contained branches, i.e if the source file was:

[user]
#@if work
  name = Raphaël Barrois
  email = raphael.barrois@example.org
#@else
  name = Xelnor
  email = raphael.barrois@polytechnique.org
#@endif

And the destination (on a non-work machine) was modified to read:

[user]
  name = Raphaël "Xelnor" Barrois
  email = raphael.barrois@polytechnique.org

Then the result of running uconf back shell/gitconfig will be:

[user]
#@if work
  name = Raphaël Barrois
  email = raphael.barrois@example.org
#@else
  name = Raphaël "Xelnor" Barrois
  email = raphael.barrois@polytechnique.org
#@endif