Setting Up A Shared Bazaar Repository

Currently I'm using a Decentralized Shared Mainline Repository. Here's my recipe...

You will of course need a server that's accessible to everyone.

Create a group for project.

$> groupadd projectname

Create an login for each of the users who will have commit access to the shared mainline.

$> adduser --ingroup projectname username

Create a directory for the repostitory inside the web servers document root

$> mkdir /var/bzr/projectname

Set the project folders group to the project groups name

$> chown :projectname /var/bzr/projectname

Set the project folders permissions

$> chmod ug+rwx,g+s,o+rx,o-w projectname

Now you can push updates

$> bzr push bzr+ssh://hostname/var/bzr/projectname

If you need to provide anonymous access to the repository one way would be to serve it with Apache.

Alias /bzr "/var/bzr"
<Directory "/var/bzr">
 Options +Indexes +MultiViews +FollowSymLinks
  AllowOverride None
  Order deny,allow
  Allow from all
</Directory>

This would allow you to do something like this

$> bzr branch http://hostname/bzr/projectname

Obfuscating IDs in URLs with Rails

There are a number of valid reasons to obfuscate IDs in URLs but it's not a replacement for authentication!

My approach to this problem is to allow the database to assign a normal serial ID, which means I don't have to maintain any extra state or use special database features. Then after it's created I save the obfuscated value of the id which I can use on later lookups.

I use Knuth's integer hash because it ensures there will be no collisions and the full range of values will be used.

In this example I'm using a signed 32 bit integer for the hashed_id because it's supported by all common Rails databases. You could however adjust MAXID to any number of bits you want but then you may have to deal with storage and conversion issues.

Model:

class Part < ActiveRecord::Base
  PRIME = 2654435761
  MAXID = 2**31-1
  def after_create
    self.hashed_id = (self.id * PRIME & MAXID)
    self.save
  end
end

Controller:

class PartsController < ApplicationController
  def show
    @part = Part.find_by_hashed_id(params[:id])
  end
end

Useful Launchpad Tips

I ran across a useful blog post today that included some useful tips for for using Launchpad that's worth sharing.

• basic of triaging
• tags
• duping bugs
• tracking upstream bugs
• email managment
• graphing bug metrics