~bzr-pqm/bzr/bzr.dev

===========================

Using Bazaar with Launchpad

===========================

Motivation

==========

Communities are different to teams

----------------------------------

The team of people required to create the initial release

of a piece of software may vary in size from one person

to several thousand people. Depending on the requirements,

the challenges involved, both technical and managerial,

can be immense. As explained in the Bazaar User Guide, selecting

"just right" processes and using tools like Bazaar to support

matching workflows can greatly help.

Success with software though requires more than a great team - it

requires a healthy, active *community*. This group is typically

far larger than the team as it includes everyone interested in

the software: the team, users, training partners, support partners,

third-party developers and so on.

Great communities are well understood in the open source world.

Their applicability extends well beyond that though: most

successful commercial software vendors are well skilled at

building and managing the communities that grow up around

their flagship products.

Like great teams, great communities don't just happen.

Good policies and guidelines are essential for

fostering the right sort of behaviour and healthy

relationships between participants. For a deeper look at

this topic, see Karl Fogel's landmark book:

`Producing Open Source Software <http://www.producingoss.com/>`_.

The need for Collaborative Development Environments

---------------------------------------------------

An intelligent toolset is also important for tracking and managing

community information and workflows. These tools are called

Collaborative Development Environments (CDEs). These toolsets are

typically web-based and manage things such as announcements,

issues/bugs, questions and answers, downloads, documents and

source code. Some examples of CDEs include

`Launchpad <https://launchpad.net>`_,

`SourceForge <http://sourceforge.net>`_,

`java.net <http://java.net>`_ and

`SAP Community Network <https://www.sdn.sap.com/irj/sdn>`_.

Helping communities work with related communities

-------------------------------------------------

Many successful products have a huge number of downstream dependencies.

In other words, a new challenge arises with success: dealing with other

communities and understanding how your changes will impact them. This is

most obvious for projects like:

* software languages, e.g. Python, PHP, Ruby, Java, Perl, etc.

* compilers, e.g. gcc, JDK, etc.

* libraries, e.g. zlib, openssl, etc.

* frameworks, e.g. Zope, Ruby on Rails, Spring, etc.

However it applies equally for popular applications on which add-ons are

built, e.g. Firefox, Thunderbird, OpenOffice.org, Drupal, Wordpress, Joomla,

etc.

Tools that assist communities work together to track and manage

issues and fixes across community boundaries are required. These

tools help people at both ends of the spectrum:

* users can report problems in their terms, e.g. rendering of image

  type X is broken in application Y on operating system Z

* developers can better appreciate the downstream impact of making a

  change or fix, e.g. fixing this bug in a graphics library will

  make the users of these 5 applications on these 10 operating

  systems happy.

People in the middle play the essential role of *joining the dots* and

communicating up and down the line. In many cases, they may also fix the

problem for end users, releasing a patch and pushing a suggested fix

to the upstream development team. Keeping track of all that over time

in a sustainable way is no easy task.

Launchpad: More development, less friction

------------------------------------------

As well as sponsoring `Ubuntu <http://www.ubuntu.com>`_ and

`Bazaar <http://bazaar-vcs.org>`_ development, Canonical

provides Launchpad, https://launchpad.net, as a free service

for the open source community. Launchpad is one of the most

exciting CDEs around for several notable reasons:

* it models relationships between many of things tracked, e.g.

  source code branches can be associated with bug fixes

* as well are managing historical knowledge,

  it supports future development planning and tracking by providing

  features such as roadmaps, milestones and blueprints

* it provides translation tools and packaging services so that

  barriers are reduced for translators and testers wishing to

  join your community and help out

* it provides a nexus for different communities to work

  together on related issues and roadmaps.

In other words, Launchpad has been designed to help your

community grow and to reduce the workflow friction both

*within* your community and *between* communities. Ultimately,

that means less time on mechanical tasks and more time for

interesting development.

Bazaar: Launchpad's VCS client

------------------------------

This tutorial looks at how Bazaar and Launchpad can be used together

and how they complement each other. It is important to remember that:

1. Bazaar can be used without Launchpad

2. Launchpad can be used without Bazaar.

By design though, their sum is greater than the individual

parts.

Finding and browsing branches using Launchpad

=============================================

Finding available branches

--------------------------

While there are many advantages in adopting distributed version

control, one of the things that disappears is the all-knowing

central server with knowledge about all available branches. Indeed

in a distributed environment, interesting branches can literally

exist in 100s of locations across the Internet (or within an

Intranet for that matter).

Launchpad fills this gap by providing a registry of branches.

Registering branches

--------------------

Branches can be uploaded to Launchpad or simply registered

as being available in an external location. Branches can also

be given a Status such as *New*, *Development*, *Mature* or

*Abandoned*.

Note: External branches can even be hosted in legacy version control

tools, i.e. CVS and Subversion. Code in these systems will be

scanned and converted to Bazaar branches on a periodic basis.

For maximum fidelity of course, it is preferable for external

branches to be hosted in Bazaar.

Browsing branches

-----------------

Branches can be listed, filtered and sorted by numerous

attributes including Name, Registrant, Author, Status, Age and

time of last commit. Browsing of branches is also provided making

it easy to see things such as:

* where the branch can be downloaded from

* how to upload changes

* recent commits and the changes made by each

* the source code of individual files for a given version.

Accessing code in Launchpad using Bazaar

========================================

Getting the code for an open source project

-------------------------------------------

As Launchpad keeps track of thousands of open source projects

and their latest code whether it be managed by Bazaar, CVS or Subversion,

Bazaar users can grab that code as easily as this::

  bzr branch lp:project-name

where `project-name` is the Launchpad project ID. Here are some examples::

  bzr branch lp:inkscape

  bzr branch lp:amarok

  bzr branch lp:python

  bzr branch lp:rails

  bzr branch lp:java-gnome

You can then browse the code locally using your favorite editor or IDE and

change the code if you wish.

If a project has multiple series registered (e.g. a development series and a

maintenance series), the latest code for a given series can be fetched using::

  bzr branch lp:project-name/series

Publishing your changes

-----------------------

Having fixed that annoying bug or added that cool feature you've always

wanted, it's time to impress your friends and make the world a better

place by making your code available to others. As explained earlier,

Launchpad is a free Bazaar code hosting service so you can push your

branch to it and others can access your code from there. For example,

assuming you are a member of the relevant team, login to launchpad like this::

  bzr launchpad-login userid

where `userid` is your Launchpad user ID.

You can then push your changes to a team branch like this::

  bzr push lp:~team-name/project-name/branch-name

Others can then download your code like this::

  bzr branch lp:~team-name/project-name/branch-name

Personal branches

-----------------

Even if you are not a member of a team, Launchpad can be used to publish

your changes. In this case, simply create a personal branch like this::

  bzr push lp:~userid/project-name/branch-name

Others can then download your code like this::

  bzr branch lp:~userid/project-name/branch-name

Note: Even when publishing to a personal branch, it is polite to notify the

upstream developers about your branch so they can pull your changes from

it if they are generally applicable to all users and meet the project's

quality standards.

Linking branches using Launchpad

================================

Associating a branch with a bug

-------------------------------

After registering a branch, you can associate it to a bug so that

people interested in that bug can track and download the fix as

it becomes available.

To do this, the steps are:

1. Navigate to the bug in question.

2. Select `Add branch` under `Actions`.

3. Select the branch.

4. Optionally set the State of the relationship. This is

   *Fix In Progress* by default but you may wish to set it

   to another state such as *Fix Available* if the branch already

   addresses the issue.

If you wish, you can also provide some arbitrary comments about

the relationship between the bug and the branch.

Changing the state in Launchpad while committing in Bazaar

----------------------------------------------------------

Bazaar and Launchpad can work together to reduce some of

the status housekeeping for you. When you commit using Bazaar,

use the --fixes option like this::

  bzr commit --fixes lp:1234 -m "..."

where 1234 is the bug ID. This will changes the State of the

bug-branch relationship to *Fix Available*. If the one commit

fixes multiple issues, the --fixes option can be specified multiple

times.

One of the cool things about this feature is that Launchpad does

not need to be accessible when making the commit. The ``--fixes``

option works by storing metadata which Launchpad will detect next

time the branch is pushed to it or scanned once online again.

Note: Launchpad will not implicitly close a bug just because a

branch is available that fixes it. There are several reasons for this.

Firstly, the branch usually needs to be merged into the trunk

(main development branch) before most teams consider it fixed.

Secondly, many teams have a separate process for confirming

bugs are fixed over and above a developer saying so.

As explained later, merge control features are currently under

development in Launchpad and automatically changing the status of

bugs to *Fix Committed* will be more appropriate once those features

are in place.

Associating a branch with a blueprint

-------------------------------------

After registering a branch, you can associate it to a blueprint so that

people interested in that blueprint can track and test the feature as

it develops.

To do this, the steps are:

1. Navigate to the blueprint in question.

2. Select `Link branch` under `Actions`.

3. Select the branch.

If you wish, you can also provide some arbitrary comments about

the relationship between the blueprint and the branch.

Managing releases using Launchpad

=================================

Integrating changes

-------------------

Once a branch has been developed and published, communities

typically go through a rigorous process before those changes

are integrated into the core product and rolled out to end users.

Some of the steps involved may include:

* peer review of the changes

* deciding which releases to include the changes in, e.g. the

  next maintenance release, the next major release, or both

* running functional regression tests

* benchmarking to ensure performance remains acceptable

* packaging into early access releases for end user testing

* documentation updates, e.g. Release Notes for the targeted

  releases

* translation of the user interface and documentation into

  multiple languages.

This section briefly looks at some of the features in Launchpad that

help get good quality code into production. Strong integration with

Bazaar is core to making this happen smoothly.

Note: Where indicated, some of the features below are still under

development. If one or more of these features interest you, please

consider joining the Launchpad beta test team at this link:

https://help.launchpad.net/JoiningLaunchpadBetaTesters. You can

then get early access to features and provide feedback to the

developers before wider roll-out.

Branch merge proposals

----------------------

After navigating to a branch in Launchpad, one of the available actions

is *Propose for merging*. This lets you nominate which branch this code

ought to be merged into.

Tracking the knowledge about which branches are proposed to be merged

into a codeline helps Release Managers keep on top of what still needs

to be completed, or can be completed, before a ship date. Using this

information, they can ensure branches are merged after completing any

necessary reviews. In the simple case, the Release Manager may manually

merge branches. In more advanced cases, the merging could be automatically

done by a robot (like `PQM`_) when the branch reaches the right state

(e.g. *Review completed*).

.. _PQM: https://launchpad.net/pqm

Code review tracking

--------------------

A number of features are under development in Launchpad to track the

states, conversations and outcomes of code reviews. These features are

expected to be integrated with branch merge proposals and branch

browsing features.

Personal Package Archives (PPAs)

--------------------------------

PPAs help developers and development teams get custom builds into the

hands of users for early testing and feedback. In other words, a PPA

allows a developer to form a community of testers who are interested

in their changes. The testing community can install the packages,

run them for the test period and then remove them cleanly from their

system.

See https://help.launchpad.net/PPAQuickStart for further details.

Translations

------------

The Translations module in Launchpad is designed to make it easy for

anyone to get involved translating applications to languages they know.

Translators are shielded from the low level details.

Launchpad keeps track of the translations for each major version of a

project separately, allowing translators to continue to improve the

translations of your stable releases while others start work on newer

versions that are still in development. Translation speed in reduced

by sharing resources across projects. Automatic suggestions, from a

library of 750,000 translated strings, and a community of 19,000

registered translators can radically cut the time required to

localise your project into many languages.

Summary

=======

The communities we join, whether off-line or on-line,

say a lot about the sort of people we are. The flip-side

to this is that the tools you choose for your community - particularly

the CDE and version control tool - can have a large impact on who

joins and how easily they can contribute.

In their own right, Launchpad and Bazaar are highly useful tools.

Together, they can:

* help your community track major assets such as source code and knowledge

* help it grow by reducing barriers to entry

* help it interact with related communities.

In particular, Launchpad is a free code hosting service for your Bazaar

branches, branches can be browsed online, branches can be linked to bugs

and blueprints, and the status of bug-branch relationships can be

automatically managed by mentioning the bug while committing in Bazaar.

Further integration is under development with the aim of streamlining

the process from *great idea* to *running code in the hands of end users*.

If you have any feedback on how you'd like to see Bazaar and Launchpad

further integrated, please contact us on the Bazaar mailing list,

bazaar@lists.canonical.com.

While designed as a free service to support open source projects,

Canonical may make Launchpad available to commercial software developers

depending on their requirements. We would be happy to hear from you

if you think Launchpad would be useful for managing your community,

open source or otherwise.