Thoughts on "Linux Apps" paper

[Michael Thayer <michael thayer oracle com>]

Dear List,

Alexander Larsson pointed me to the "Linux Apps" paper after I asked him 
some questions regarding his "Glick2" project.  I am sure you have had 
no shortage of thoughts and feedback on the paper, but as that is the 
price you have to pay for working in the public eye I would still like 
to add a bit of my own from the perspective of a developer with some 
experience of packaging out-of-distribution software on Linux, and some 
interest in the subject.

An important point I would like to make is that many of the goals you 
set in the paper are actually possible today.  Usually in rather 
inelegant ways, and perhaps not quite the way you envision them in the 
paper, but possible nonetheless.  You can create an app in the style of 
an OS X application bundle.  The app needs some way of finding its 
resources relative to the executable.  This can be solved without 
mounting tricks, see "gnulib"[1] for example.  Obviously this will not 
work without modifying the programme source, but since I presume that 
the majority of software you are targeting is either open source or 
packaged by the author of the software getting modifications upstream 
should be quite feasible.  Again OS X-like, the app will need to be run 
through the file manager the first time a user executes it (but since 
they have just installed it by copying it that is not such a burden); on 
first execution the app sets up any user-local search path directories 
to point to it.  For example (example, not recommendation), the app can 
put a symbolic link to its icon in ${HOME}/.icons.  And of course 
application sand boxes can be done relatively transparently - as a proof 
of concept from my corner (you would probably want to use a different 
method in practice!) see VirtualBox in seamless mode, which works fine 
for X11 applications - no Wayland needed here.  (I realise that some of 
our Guest Additions tools could do with some polishing; a better 
seamless mode is on my personal to-do list, though with no date set for 
completion.  I hope to make the code as generic as possible to make as 
much as possible usable in other sand box contexts.)

To make a long story short, as well as planning ways to make apps 
possible in the future, it might make sense to catalogue best practices 
for doing them now.  That is a goal you could reach a lot faster, and 
once you have such a catalogue and people start looking at it I suspect 
that they will also start finding ways of doing it better now and start 
fixing the bits of the system which get in their way.

I have quite a bit more that I could write, but this e-mail is already 
long enough and it is getting rather late in this time zone.  If the 
list subscribers are not too annoyed at me yet (please let me know!) I 
plan to follow it some time with a more detailed look at individual 
points of the paper.

Thank you for your patience.

Regards,

Michael

[1] 
https://www.gnu.org/software/gnulib/manual/html_node/Supporting-Relocation.html
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