Package Manager Design Doc

Some design overview of how addons auto-update should work (or how it should not work)

Basic Requirements

Add-on update should:

Be unblocking, meaning interface should be responsive during all update procedure
Non-intrusive, meaning it should not do things silently, without artists asking to actually update addon or all add-ons.
Gracefully handle any exceptions, rollback to a previously installed addon if any update error happens
Perform functionality to update to any version (including older ones)
for the cases when some regression happens in addon and stops production
Any failure with installation/connections/partially successful downloads… etc
must be cleanly recovered from.
Hanging processes must be handled elegantly. (using time-out for eg).
Be flexible in design to support both public addons update and addons which are distributed via cloud, blender market and so on
Never store any credential details
Not require any separate tool (git / svn / hg) to be installed separately from Blender
(Plain Python + Requests should easily be enough in this case).
Support multiple repositories
(not be locked into a single repository).
Possibilities to be used for non-addons (Not essential, however as add-ons are simply a package of data we’re not concerned with exact details of their contents, there is no reason to hard-code in add-ons… other kinds of extensions may be useful)

Support mirrors?
Package signing?
Binary packages? (please no!)
Package format? (we can postpone this one)
How to handle version compatibility?
(when updating Blender breaks a package or the other way around).
Support for multiple Blender versions.
(The possibility for a package provider to host a single package for multiple versions - but maybe eventually useful to support!).
Authentication?
(which auth model to use, do we support multiple ones etc)
Find a good real-world addon(s) which can be used for demonstrating the system in real action
(without all this “works with my localhost!” rubbish)

Q: Why do this at all?
A: As add-on development has increased, developers are choosing not to use Blender’s repositories for their own projects and instead using 3rd party source hosting.
Having to manually install and update add-ons isn’t so convenient.
Its also nice for developers to be able to send updates to users more easily.

Q: Who is this for?
A: This is for users, developers who want their users to be able to access their latest work.
Also for companies who develop add-ons, however this will remain vendor agnostic.