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Ubuntu Open Week - Packaging Firefox Extensions - Alexander Sack - Wed, Apr 30, 2008

=== jcastro changed the topic of #ubuntu-classroom to: Ubuntu Open Week | Information and Logs: https://wiki.ubuntu.com/UbuntuOpenWeek | How to ask questions: https://wiki.ubuntu.com/UbuntuOpenWeek/Rules | Ask questions in #ubuntu-classroom-chat, prefaced with "QUESTION:" |See https://wiki.ubuntu.com/UbuntuOpenWeek/JoiningIn to filter out channel noise | Current Session: "Packaging Firefox Extensions" - Alexander Sack

[19:00] <jcastro> ok, next up is Packaging Firefox Extensions with asac!

[19:00] <asac> thanks jcastro

[19:00] <jcastro> asac: take it away!

[19:00] <asac> Welcome to the Firefox Extension Packaging world.

[19:00] <asac> First I want to give some general information about extension packaging. In particular the why.

[19:01] <asac> (this questions pops-up frequently so i think its good to address here upfront)

[19:01] <asac> Then I'll go and give a quick review on what was done during the hardy cycle and where we plan to go 

for the future.

[19:01] <asac> Next, I will give a short insight in how you can contribute.

[19:02] <asac> and finally we'll go and exercise some basics by packaging an extension. For that we will repackage 
ubufox which should help to show.

[19:02] <asac> the general idea

[19:02] <asac> So why do we want extensions packaged. Isn't addons.mozilla.org good enough?

[19:03] <asac> addons.mozilla.org surely is a great portal for getting extensions and automatically updating them.

[19:03] <asac> But its not all positive:

[19:03] <asac> 1. it doesn't allow you to install extensions globally easily.

[19:03] <asac> 2. more important is the fact that automatically updated extensions might not match the quality 
expectations of users, especially in corporate environments

[19:04] <asac> packaged extensions would allow us to stabilize extensions and given the track record of crashes due to 
extensions it looks worth to do

[19:05] <asac> Any questions on these?

[19:05] <asac> < toobuntu> QUESTION: Are Ubuntu packaged Firefox extensions meant to replace the 
-install-global-extension option? There seem  to often be issues with permissions and configs, and they globals just 
haven't work out well for me in a multiuser  environment.

[19:06] <asac> right the install global option is not really working properly

[19:06] <asac> packages don't replace it, but its the better approach for distributing extensions

[19:06] <asac> ok lets go on

[19:07] <jcastro> * waiting on questions *

[19:08] <asac> OK, lets move one. What was done in hardy?

[19:09] <asac> In hardy we started to package extensions using our new mozilla-devscripts helpers that make packaging 
quite easy

[19:09] <asac> we will use this helper to package the example later on

[19:09] <asac> anyway, It was hard work, especially since most extensions were not yet available for firefox 3.

[19:10] <asac> But thanks to the hard work of contributors we managed to get more extensions into the archive than 
ever before.

[19:10] <asac> An overview of packages can be seen on the firefox 3 extension page: 
https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions which is used to document the data needed to properly maintain 
extensions in ubuntu.

[19:11] <asac> so in short, I would declare this a victory and i want to express my thanks to all involved in making 
that happen

[19:11] <asac> However, we are still not where we would like to be and for intrepid we are planning to scale this up.

[19:12] <asac> Based on our experiences from the hardy cycle we discussed how to better automize the extension 
packaging process.

[19:12] <asac> which is a requirement to maintain as many extensions as possible in the future with as little manpower 
as possible.

[19:13] <asac> of course we will still need  you on the manpower side ;)

[19:13] <asac> as not everything can be done automatically

[19:14] <asac> For those intereseted the (not yet finished) current state of that discussion can be found on 
https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions/LargeScaleMaintenance

[19:14] <asac> Any questions?

[19:15] <jcastro> < toobuntu> QUESTION: If we encounter an extension that is not already packaged, we should make an 
effort to package it, then?   Please tell us what's involved...

[19:15] <asac> i think we will come to that later. but basically all starts with adding the extension to the 
https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions wiki page and gather all the data in the table

[19:16] <asac> once that is done and everything is available, the packaging can start.

[19:16] <asac> its not even required that you do the packaging on your own. getting the data is often harder than 
packaging itself

[19:16] <asac> :)

[19:16] <asac> especially sorting out licensing ;)

[19:16] <asac> Next

[19:17] <jcastro> < MiSc0110> QUESTION: Are this packaged extensions for Firefox only, or are they for Thunderbird 
too?

[19:17] <asac> currently we focussed on extensions for firefox

[19:18] <asac> but that doesn't mean that we won't do the same for thunderbird in future.

[19:18] <asac> I agree, that we should add a similar wiki page for thunderbird extensions. the process will be similar 
and we can certainly maintain include thunderbird extensions in our intrepid work

[19:19] <asac> Next

[19:19] <asac> (if you are interested in particular thunderbird extensions, please come to #ubuntu-mozillateam channel 
and ask there)

[19:20] <asac> ok ... lets move on

[19:20] <asac> So, how can you contribute?

[19:20] <asac> obviously you can help doing the packaging work. after some practice you will usually learn quickly how 
to package extensions

[19:21] <asac> and usually reach an expertise level just after a few extensions.

[19:21] <asac> packaging extensions is definitly a good starter task

[19:21] <asac> but as said above, you can also contribute by suggesting new extensions

[19:21] <asac> and getting all the data required before we can start packaging them.

[19:22] <asac> for that you do not need any special technical skills

[19:22] <asac> as said above the most important things you need to figure before you suggest an extension for 
packaging is to check:

[19:22] <asac> 1. does the .xpi include a license file - and is the license suitable for ubuntu

[19:22] <asac> 2. does the xpi support firefox 3 - if not, does it work if you disable compatibility.

[19:23] <asac> however, extension authors are not really used to licensing and often they just don't know the 
difference of including a license in the .xpi or just stating the license on a website

[19:24] <asac> so if there is no license file in the .xpi it makes sense to contact the author, explaining the 
situation and asking him politely to include a license file in the top level directory of the xpi

[19:24] <asac> Which license is suitable and how to check if an extension works with firefox 3 is documented in the 
first paragraph of the https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions wiki page.

[19:24] <asac> (there might be more licenses, but the list should cover most cases)

[19:25] <asac> Questions?

[19:25] <ompaul> Question: how does one disable compatibility

[19:25] <asac> this is documented in the top most paragraph on the 
https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions page

[19:26] <asac> you have set the extensions.checkCompatibility to false

[19:26] <asac> in about:config

[19:26] <asac> next

[19:27] <asac> OK, lets get started on the packaging excersize for today.

[19:27] <asac> I wrote a basic packaging page once:

[19:27] <asac> https://wiki.ubuntu.com/MozillaTeam/Firefox3Extensions/Packaging

[19:27] <asac> You do not need to read it now, please just do what is listed in the Prerequisites section (on top of 
that page).

[19:28] <asac> (if you want to do this excersize)

[19:28] <asac> OK, lets wait a few minutes for those of you who want to follow ...

[19:28] <asac> feel free to ask questions during this excersize whenever you want :)

[19:33] <asac> ok, while you are finalizing your preparations some words.

[19:33] <asac> packaging usually starts with setting up an upstream branch

[19:34] <asac> this is what the ubufox.upstream branch is.

[19:34] <asac> its a bit unfair, because ubufox ships decent sources, and in real live you need to convert .xpis to 
proper upstream branches first

[19:34] <ompaul> rogfou> QUESTION: what is the policy for updating such extension packages? especially for an LTS 
(it's ok to answer this question after the exercise if prefered)

[19:35] <asac> our largescalemaintenance approachs plans to provide latest extensions to -backports for _all_ stable 
distributions

[19:36] <asac> unless there is a serious bug we won't send new upstrewam versions to -updates though. but i think 
thats a good compromise

[19:36] <asac> serving our users with a somewhat similar experience than AMO ... just QAed and opt-in

[19:36] <asac> end of answer :)

[19:36] <asac> ok, lets go on

[19:37] <asac> so basically you need an .upstream branch. based on that you create a packaging branch. to do so run:

[19:37] <asac> bzr branch ubufox.upstream ubufox.ubuntu

[19:37] <asac> this will create a ubufox.ubuntu directory next to your ubufox.upstream branch

[19:38] <asac> now we have to add the initial packaging.

[19:38] <asac> for that we copy the debian/ directory from the XPI.TEMPLATE into the ubufox.ubuntu directory

[19:38] <asac> e.g. cp -r XPI.TEMPLATE/debian ubufox.ubuntu/

[19:39] <asac> then you switch to the ubufox.ubuntu directory

[19:39] <asac>   cd ubufox.ubuntu

[19:39] <asac> and add the new files to the branch

[19:39] <asac>   bzr add debian

[19:40] <asac> the output i get from this looks like: http://paste.ubuntu.com/8993/

[19:40] <asac> the content of the ubufox.ubuntu directory looks like http://paste.ubuntu.com/8994/ after doing that

[19:41] <asac> now you have to edit the template files

[19:41] <asac>  1. changelog: change the package name in the first line to match the package you are trying to package

[19:41] <asac> and change the name to match your name/email

[19:42] <asac> the changelog currently contains some documentation about the best-practices on how to commit, but 
thats not important for this session.

[19:42] <asac> usually you would also change the version of the changelog to match the upstream version (which is in 
install.rdf)

[19:43] <asac> so in this case you would use 0.6~a1-0ubuntu1

[19:44] <asac> 2. control: here you have to change the Source: field to match your package (ubufox) and the 
XSBC-Original-Maintainer field (use your name if you want to be the primary packaging contact)

[19:44] <asac> usually you would also change the Vcs-Bzr field, but since this is just an excersize you can skip this

[19:44] <asac> together with fixing package description and so on

[19:45] <asac> in case you would create a thunderbird extension you would also adapt the Depends: field accordingly.

[19:45] <asac> the template should cover the most common firefox cases (usable for firefox 2 + firefox 3)

[19:46] <asac> 3. copyright ... you don't need to edit this for this excersize. usually you would fill in the license 
of the extension you package

[19:47] <asac> oh, for 2. i forgot that you need to change the Package: field as well (ubufox)

[19:48] <asac> 4. rules: here you have to change the fields MOZ_EXTENSION_PKG and the MOZ_XPI_BUILD_COMMAND

[19:48] <asac> the MOZ_EXTENSION_PKG would be the value you added to the Package: field in control

[19:49] <asac> the MOZ_XPI_BUILD_COMMAND is expected to produce an .xpi in the top level directory

[19:49] <asac> the rules files looks like http://paste.ubuntu.com/8996/ for me now

[19:50] <asac> ok lets sync up

[19:51] <asac> my changelog looks like: http://paste.ubuntu.com/8998/

[19:51] <asac> my control looks like: http://paste.ubuntu.com/8999/

[19:52] <asac> and the rules like above (http://paste.ubuntu.com/8996/)

[19:52] <asac> when you are done you can commit everything like

[19:52] <asac>   bzr commit -m "* initial packaging (0.6~a1-0ubuntu1)"

[19:52] <asac> and do a test build

[19:52] <asac>  dpkg-buildpackage -rfakeroot -b

[19:53] <asac> ok, kind of a rush, but i hope you could follow

[19:53] <asac> questions so far?

[19:53] <ompaul> <progfou> QUESTION: does the update policy specify if one should update only on security issue and 
major bugs correction (data loss) or also on added new features?

[19:53] <asac> problems?

[19:53] <asac> we want latest extensions everywhere ... thats why our policy for -backports allows new features

[19:53] <ompaul> <artir> dpkg-buildpackage: fallo: fakeroot debian/rules binary gave error exit status 2

[19:54] <asac> for -updates we have the same policy as the ubuntu distribution

[19:54] <asac> e.g. only security related changes that are minimal.

[19:54] <asac> however, security issues have to be considered case-by-case

[19:55] <asac> there might be cases where updating to latest upstream might be better, but usually we want minimal 
patches for security changes

[19:55] <asac> next

[19:55] <asac> ah

[19:55] <asac> for that error, please post the complete output

[19:56] <ompaul> <artir> http://paste.ubuntu.com/9002/

[19:58] <asac> anyway. i think time is running low. if you want to finish this excersize feel free to join us in  
#ubuntu-mozillateam. we can surely sort out the final issues there :)

[19:58] <ompaul> mailing list?

[19:58] <asac> same goes for further questions. you can ask in #ubuntu-classroom-chat, or in the mozillateam channel

[19:59] <asac> mailing list is: ubuntu-mozillateam AT lists DOT ubuntu DOT com.

[19:59] <asac> but you need to be subscribed. most discussion happens in #ubuntu-mozillteam

[19:59] <ompaul> asac, thank you \o/

[19:59] <asac> thanks for joining ... and thanks for helping for extension packaging in future

[19:59] <asac> hope you had some fun at least ;)

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