ubuntu-phone team mailing list archive

[Jamie Strandboge <jamie@xxxxxxxxxxxxx>]

On 01/22/2014 11:10 AM, Colin Watson wrote:
> As I understand it, the agreement from the app-frameworks discussion at
> UDS was that we wanted to be able to offer slightly more fine-grained
> framework declarations, and allow apps to require multiple frameworks.
> (This would also help with ABI breaks like Qt 5.2; no reason to require
> QML-only apps to change just because we change an implementation detail
> of the platform that only affects native-code apps.)  I planned for this
> when laying out the Click file formats, but it didn't make the
> implementation cut for 13.10.
> 
> The code currently in lp:click, which will become version 0.4.14,
> extends the "framework" manifest field a bit to support this.  With
> this, assuming appropriate declaration files in
> /usr/share/click/frameworks/, apps will be able to do something like
> this:
> 
>   "frameworks": "ubuntu-14.04-qml, ubuntu-14.04-html5"
> 
> click does not care what the names are; these are just examples.  The
> idea here is that if we do need to do ABI breaks in the future, at least
> this limits the set of affected apps, and presumably we can keep the
> most widely-used ones more stable.  I would suggest that we don't go
> overboard on how fine-grained we make this, so that app authors don't
> need to make overly complex decisions.
> 
> If you have any (non-bikeshed) concerns about this, please let me know
> before I get the landing ask for click 0.4.14 approved. :-)
> 

This affects click-apparmor and while we did talk about this a bit at UDS, I
want to restate it here. I realize click doesn't care about this, but will we
expect things like this:

"frameworks": "ubuntu-sdk-13.10, ubuntu-14.04-qml"

If so, that complicates things greatly because there is one APP_ID defined per
app in the click package and therefore only one apparmor profile per app.
Because different frameworks may have different policy versions, click-apparmor
must guess which apparmor policy version to use when generating the profile (ie,
ubuntu-sdk-13.10 uses ubuntu/1.0 and ubuntu-14.04-qml might use ubuntu/1.1). I
strongly recommend we not support this, but instead:

 * when adding frameworks, make sure we define/use a 'base' framework. Ie, for
   "ubuntu-14.04-qml, ubuntu-14.04-html5", the base framework is "ubuntu-14.04".
   We should not use something like "ubuntu-14.04-qml, ubuntu-html5-14.04".
 * when adding a framework, we need to understand what a microversion means if
   we are going to use it. Ie, in terms of apparmor policy, is there a
   difference between ubuntu-14.04-qml and ubuntu-14.04.1-qml such that
   "ubuntu-14.04-qml, ubuntu-14.04.1-qml" is supposed to be supported in the
   click manifest?
 * click-review-tools needs to be adjusted to enforce the outcomes of this
   thread

With the above, an app developer then has a choice of either uploading
differently versioned apps with different framework bases to the the store or
declaring the earliest (supported) framework desired for the app.

As an aside, I'd like to see the outcomes of this codified somewhere so that the
SDK, foundations/phonedations, security, community and app store teams are all
on the same page and to ensure adding a new framework works correctly.

-- 
Jamie Strandboge                 http://www.ubuntu.com/

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