Older blog entries for ctrlsoft (starting at number 100)

Book Review: Bazaar Version Control

Packt recently published a book on Version Control using Bazaar written by Janos Gyerik. I was curious what the book was like, and they kindly provided me with a digital copy.

The book is split into roughly five sections: an introduction to version control using Bazaar's main commands, an overview of the available workflows, some chapters on the available extensions and integration, some more advanced topics and finally, a quick introduction to programming using bzrlib.

It is assumed the reader has no pre-existing knowledge about version control systems. The first chapters introduce the reader to the concept of revision history, branching and merging and finally collaboration. All concepts are first discussed in theory, and then demonstrated using the Bazaar command-line UI and the bzr-explorer tool. The book follows roughly the same track as the official documentation, but it is more extensive and has more fancy drawings of revision graphs.

The middle section of the book discusses the modes in which Bazaar can be used - centralized or decentralized - as well as the various ways in which code can be landed in the main branch ("workflows"). The selection of workflows in the book is roughly the same as those in the official Bazaar documentation. The author briefly touches on a number of other software engineering topics such as code reviews, code formatting and automated testing, though not sufficiently to make it useful for people who are unfamiliar with these techniques. Both the official documentation and the book complicate things unnecessarily by listing every possible option.

The next chapter is a basic howto on the use of Bazaar with various hosting solutions, such as Launchpad, Redmine and Trac.

The Advanced Features chapter covers a wide range of obscure and less obscure features in Bazaar: uncommit, shelves, re-using working trees, lightweight checkouts, stacked branches, signing revisions and using e-mail hooks.

The chapter on foreign version control system integration is a more extensive version of the public docs. It has some factual inaccuracies; in particular, it recommends the installation of a 2 year old buggy version of bzr-git.

The last chapter provides quite a good introduction to the Bazaar APIs and plugin writing. It is a fair bit better than what is available publically.

Overall, it's not a bad book but also not a huge step forward from the official documentation. I might recommend it to people who are interested in learning Bazaar and who do not have any experience with version control yet. Those who are already familiar with Bazaar or another version control system will not find much new.

The book misses an opportunity by following the official documentation so closely. It has the same omissions and the same overemphasis on describing every possible feature. I had hoped to read more about Bazaar's data model, its file format and some of the common problems, such as parallel imports, format hell and slowness.

Syndicated 2013-09-28 17:33:00 from Stationary Traveller

Migrating packaging from Bazaar to Git

A while ago I migrated most of my packages from Bazaar to Git. The rest of the world has decided to use Git for version control, and I don't have enough reason to stubbornly stick with Bazaar and make it harder for myself to collaborate with others.

So I'm moving away from a workflow I know and have polished over the last few years - including the various bzr plugins and other tools involved. Trying to do the same thing using git is frustrating and time-consuming - and I'm sure that'll improve with time. In particular, I haven't found a good way to merge in a new upstream release (from a tarball) while referencing the relevant upstream commits, like bzr merge-upstream can. Is there a good way to do this? What helper tools can you recommend for maintaining a Debian package in git?

Having been upstream for bzr-git earlier, I used its git-remote-bzr implementation to do the conversions of the commits and tags:

% git clone bzr::/path/to/bzr/foo.bzr /path/to/git/foo.git

One of my last changes to bzr-git was to add a bzr git-push-pristine-tar-deltas subcommand, which will export all bzr-builddeb-style pristine-tar metadata to a pristine-tar branch in a Git repository that can be used by pristine-tar directly or through something like git-buildpackage.

Once you have created a git clone of your bzr branch, it should be a matter of running bzr git-push-pristine-tar-deltas with the target git repository and the Debian package name:

% cd /path/to/bzr/foo.bzr
% bzr git-push-pristine-tar-deltas /path/to/git/foo.git foo
% cd /path/to/git/foo.git foo
% git branch
*  master
   pristine-tar

Syndicated 2013-06-02 00:01:00 from Stationary Traveller

OpenChange 2.0 released

Apparently 'tis the season for major software releases.

Julien has just announced the release of OpenChange 2.0, codenamed quadrant. This release fixes a number of important bugs and enables integration with SOGo.

With the SOGo backend, it is now possible to set up an Exchange-compatible groupware server that can be accessed from Outlook without the need to connect any connectors.

See the release notes for more details.

Syndicated 2013-02-08 19:00:00 from Stationary Traveller

Bazaar: A retrospective

For the last 7 years I've been involved in the Bazaar project. Since I am slowly stepping down, I recently wrote a retrospective on the project as I experienced it for the last 7 years.

Thanks to a few kind people for proofreading earlier drafts; if you spot any errors, please let me know in the comments.

Syndicated 2012-12-19 21:36:43 from Stationary Traveller

Samba 4.0.0, finally

This afternoon we released version 4.0.0 of Samba. This is a significant milestone, and I'm very proud of the result. Samba 4 is the first version that can be a domain controller in an Active Directory domain.

We embarked on this journey almost a decade ago - the first commit is from August 2003. It's been a long and bumpy ride. I hardly recognize the people in this team photo from 2003 (I'm second from the left).

A lot has happened in that time. We wrote a few million lines of code. We migrated from CVS to Subversion to Git. We've drifted apart and grown back together as a team.

In my youthful naivity I predicted a release "within 1 or 2 years" during a talk at the NLUUG in 2004. But Active Directory was a lot harder than we thought, and there were quite a few other distractions as well. I'm glad this release, which is by far the biggest and longest running software project I have ever worked on, has finally happened.

Some older RCs of Samba 4 have already been packaged for Debian and Ubuntu, in the samba4 source package. For Debian jessie, these will be integrated into the main samba source package. Please use experimental if you do want to try the existing packages, as it is most up to date.

Syndicated 2012-12-11 17:00:00 from Stationary Traveller

Documentation

From LWN's weekly edition:

Documentation is the sort of thing that will never be great unless someone from outside contributes it (since the developers can never remember which parts are hard to understand).

—Avery Pennarun

Syndicated 2012-11-30 23:00:00 from Stationary Traveller

Back to blogging

Hello Internet. After a long silence and several fights with Serendipity I am back.

The contents from my old Serendipity install have been migrated to restructuredText in pelican. Among other things, this means I can now get rid of the last PHP install I had left on my server.

Syndicated 2012-11-26 02:17:00 from Stationary Traveller

Last day at Canonical

This Friday will be my last day at Canonical.

It has been a lot of fun working here. There is so much I have learned in the last three years. I'm going to miss my colleagues.

Over the last couple of months I have slowly stepped down from my involvement in Bazaar and the Bazaar packaging in Debian and Ubuntu. I would like to stay involved in Ubuntu, but we will see how that goes.

I'm taking some time off until the end of the year to see the world and hack, before starting something new in February.

Syndicated 2012-10-16 22:00:00 from Stationary Traveller

Summer of Code 2011

The Samba team is once again participating in the Summer of Code this year. This year we have 4 students working on various projects related to Samba.

This year I am mentoring Dhananjay Sathe, who is improving the GTK+ frontends for Samba. In particular, he is making it possible to manage shares and users of a remote Samba or Windows machine.

Dhananjay is also blogging about his progress.

Syndicated 2011-07-18 08:53:05 from Stationary Traveller

libapache2-mod-bzr

During the last two days I hacked together a Bazaar module for Apache. This module makes it possible to easily enable the Bazaar smart server for Bazaar branches. It also can display a simple placeholder page for Bazaar branches without working tree. It's surprisingly easy to write Apache modules.

The main advantage this has over a mod_wsgi / mod_python / mod_fcgi setup is that it doesn't require any additional Python hacking on the users side or other configuration outside of Apache, and it doesn't require configuration for each single branch in the Apache configuration. In the future I'd also like to support the settings "BazaarFrontend Wikkid" and "BazaarFrontend Loggerhead".

The configuration is currently as simple as:

LoadModule bzr_module /usr/lib/apache2/modules/mod_bzr.so
BazaarSmart on
BazaarFrontend Basic

in your apache2.conf. The BazaarSmart and BazaarFrontend directives can appear in or clauses as well, if you'd like to have different behaviour for different directories.

At the moment this project is a proof of concept, and probably not something you would want to run in production. For example, there is no way to limit the access to a branch to read only. I need to double-check there are no threading issues.

Testing and patches are welcome. The project is hosted here:

• https://launchpad.net/apache-bzr

Syndicated 2011-01-02 19:07:53 from Stationary Traveller