Lumiera
The new emerging NLE for GNU/Linux

This Debian-Depot is part of the Lumiera build infrastructure. It is managed automatically, based on the reprepro tool by Bernhard Link

The Lumiera debian package

As our whole infrastructure relies heavily on the Git version management tool, it’s only natural also to organise the (debian) packaging with the help of Git. Fortunatlely, there is a nifty tool called git-buildpackage, written by Guido Günther exactly for this purpuse: It treats the debianisation as a branch in the Git repository, forking off the mainline at the release point.

For Lumiera, this debianisation branch is called deb and can be found in the git:/git.lumiera.org/debian/lumiera repository.

To (re)build the debian package

  1. git clone git:/git.lumiera.org/debian/lumiera

  2. mkdir pack.deb

  3. cd debian

  4. git-buildpackage --git-upstream-branch= RELEASE-TAG

— here RELEASE-TAG denotes the point in the Git history, which should become the reference source and be packaged into the *.orig.tar.gz. Usually, it’s just sufficient to use master for that purpose.

Debian-Depot for installation via Apt

While it is easy just to build a debian package and then install it locally through dpkg -i, if we want to support automated installation and upgrades using the Apt package manager, we need to build up more infrastructure. The primary reason is that for any source package, a multitude of binary packages might be built for different architectures; moreover, we want to support several different distributions. For this purpose,the Apt package manager requires a precisely defined folder structure, accessible online via http: or ftp:. For maintaining this folder structure, there are three concievable levels of complexy:

minimal layout, manual maintainance

place everything in a single directory accessible online. Use only one pseudo-distribution and call the (single) component '.\' — just dump packages into the directory and update the packages list

multiple distributions and components, pool directory

this setup is already a full-blown debian depot, just there are some limitations on the flexibility: there might be only one version of each package per distribution, and all different distributions use a shared pool (and thus require different packages to be labeled stringently)

major distribution or mirror site

similar to the above, this is a complete debian depot, but it is backed by a database and allows for much more flexible configuration and is highly automated.

For Lumiera, it seems the middle option is the right choice: while it still keeps the infrastructure simple, it allows for multiple distributions (Debian/stable, Ubuntu….) and multiple components (experimental, development, release). The mentioned reprepro tool provides this degree of functionality: Basically, this is a fixed directory structure with some control files; the frontent is a commandline tool with a plethora of options and quite some automation- and extension hooks. Internally, it uses an embedded BerkelyDB.

Using reprepro, existing source, binary or comined packages can be added (imported) into the structure with a single command; the files comprising the package are then added automatically to the pool directory and all the indices, directories and GPG signatures are created and updated automatically. Previous versions of the same package are purged, when not needed by any existing package anymore

everyday usage

import a package

reprepro -V -C experimental include squeeze lumiera_0.pre.01-1+squeeze_i386.changes

this adds the given binary lumiera package, together with all sources and the original tarball to the squeeze repository, into the experimental section

dump out an entire repository

reprepro -V export squeeze

this will regenerate all of the indices, signatures and metadata of the squeeze repository

Configuration

The current configuration and the state of the Debian Depot index files is tracked is a separate branch in the debian/lumiera repository. (Note: this is a somewhat unconventional setup, insofar the depot branch tracks a directory tree completely separete from the main lumiera source tree tracked by the deb branch; I choose this layout because of the marginal relevance of this depot management; I just didn’t want to create yet another not so useful Git repository…)

Note
some special details to note in our setup
  • each block in the distributions file defines a repository for a “distribution” (e.g. Squeeze, Lucid, Maverick). Within such a repo, there are sections named Components.

  • The override files mentioned in the configuration allow to overwrite / replace arbitrary fields in the metadata of all packages added to that distribution.

  • In this setup, we enabled the tracking function: thereby reprepro will keep track of the dependencies between binary packages, signatures, debianisation patches and original upstream tarballs. Never packages overwirte older ones — at any time there is at most one version of a package in the repository. Parts not referred to anymore are automatically discareded. In our configuration, they are moved into the morguedir

  • Please make sure the gpg signing key is in proper order, because it protects against evil spirited manipulations.

current setup 3/2011

While later we want to automate most of this packaging business, currently it’s done semi-manual. Mostly, Ichthyo builds the packages on his local PC (or a VM) and then adds/imports them to the reprepro — changes are then propagated to lumiera.org via rsync; as kind of a backup, the index files are also pushed to Git.

rsync -rclvz --progress --partial --delete /local/filesys/path/to/Lumirep/depot/ ichthyo@www.lumiera.org:/var/local/www_debian