Nightly Subsurface AppImage for most Linux distributions

[Dirk Hohndel]

> On Oct 18, 2015, at 7:51 AM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>> the concept is great as an optional scenario, but it forces the
>>> applications to do gymnastics if it wishes to maintain a folder where
>>> the user can edit or update bundled files, manually or via the UI.
>>> having an optional install in such a case has benefits.
>> 
>> Well, a copy-on-write FUSE filesystem might be a way to achieve this
>> while still maintaining the AppImage objectives; it would make the
>> AppImage appear r/w when it is in fact r/o. Changed files would go
>> somewhere in $HOME but would look to the application as if they were
>> edited in the AppImage. Could probably be done, but is there really so
>> much need for it?
> 
> it will leave it to Dirk (the Subsurface maintainer) to comment more
> on this topic as i'm not very familiar with the Linux installation
> process and copy-on-write FUSE fs.
> on Windows we have the HTML file in a RW location next to the binary,
> so that's not even an issue (if we neglect the fact that the HTML
> changes apply to all users).
> but the software is considered installed (uncompressed from the
> deployment package) and it allows easy W modifications, where the only
> downside is the uncompressed size.

We need to make sure they are moved to ~/.subsurface on Linux.

>>> i often make
>>> updates to some of the 200MB files and wish to implement a
>>> download-updates mechanic, which only touches some large library files
>>> and possible the main executable
>>> (...)
>>> how would you approach this silly big CAD software example in a
>>> portable OS manner?
>> 
>> Use something like zsync to update the AppImage by only downloading
>> the parts of it that have changed. Ubuntu uses this for their nightly
>> ISO builds. http://zsync.moria.org.uk
> 
> i don't think this makes much sense for the Windows installer, so
> that's not really a portable solution.
> then again, i have no idea how zsync works...

But remember, Lubomir - we are only talking about AppImages for Linux.
Nothing will change for Windows.

> ideally:
> - as the author of the huge CAD software i would write a update method
> that works on all platforms (e.g. with Qt - HTML download with local
> file replacement)
> - AppImage would be the way to distribute the package on Linux
> - if the user wants to update the CAD software on a regular basis
> he/she can do an AppImage --install and delete the original AppImage.
> - once the AppImage is installed, it's now part of a RW filesystem and
> the above update method works without a problem.
> - no third party tools in the process and no browsers...the user just
> starts a small "updater" GUI app which downloads the huge CAD software
> packages.
> - this is how the Android SDK is managed on Windows; not sure about other OSes.

I think you are putting requirements on AppImage that are beyond what
is needed at this stage.

Yes, the question of granular updates will be asked at some point, but
today when I update the Windows binary that's an 80MB download and
I have heard zero complaints about that... Yes, this would be different
for a 2GB download. But I hope Subsurface never grows to that size.

/D