root'ing the netRamblings from a a coding sysadmin

Those days I faced the need of moving a set of Bazaar branches into a set of Git repository, and althought I already knew about Tailor, but I wanted a one-shot conversion and Tailor is more, ahem, tailored for periodic synchronization. So I decided to try git fast-import, because I already knew about bzr fast-import plugin which is inspired by the Git version of the thing. The Bazaar plugin includes a bzr-fast-export script which can be used to feed input data to git fast-import.

First, we need to install the Bazaar plugin. This one is easy:

mkdir -p ~/.bazaar/plugins
cd ~/.bazaar/plugins
bzr get lp:bzr-fastimport fastimport

I will be importing three branches into a Git repository, so we need to create a Git repository:

mkdir ~/myproject.git
cd ~/myproject.git
git --bare init

I suppose you have three related Bazaar branches:

• ~/myproject is the main branch of the project. It will be imported as master branch in Git.
• ~/myproject.branch-a and ~/myproject.branch-b are two branched whose parent is the first one.

alias bzrexp="~/.bazaar/plugins/fastimport/exporters/bzr-fast-export"
bzrexp --export-marks=../marks.bzr ../myproject \
   | git fast-import --export-marks=../marks.git
bzrexp --marks=../marks.bzr --git-branch=branch-a \
   ../myproject.branch-a | git-fast-import \
   --import-marks=../marks.git --export-marks=../marks.git
bzrexp --marks=../marks.bzr --git-branch=branch-b \
   ../myproject.branch-b | git-fast-import \
  --import-marks=../marks.git --export-marks=../marks.git

Voilà! It will run in a snap, the limit will be your disk speed, as both the exporter and the importer are very fast.

This entry was posted on Thursday, November 20th, 2008 at 1:44 pm and is filed under Toolchain. You can follow any comments to this entry through the RSS 2.0 feed. You can leave a comment, or trackback from your own site.