From BlenderWiki

GSoC 2016 Python Package Manager - Server-Client Plans

This page aims to document in detail the plans for server-client communication, what will be hosted server-side, and other specifics for my project. Most everything will need to be decided on before I begin coding.

Sybren asked that I create a wiki page answering a bunch of questions he emailed me, so that will be my aim here. I'll try to answer questions as best as I can for now, and those I cannot yet give a firm answer for, I will discuss with others.

Server-Client Communication

How are the client and the server going to communicate?

The server and client will communicate over HTTPS.

Am I going for a RESTful interface with JSON over HTTP? Or something else?

Yes, Blender will request a single JSON file holding the information about all add-ons registered with the index. As per Sybren's suggestion, this file will be cached by Blender, and requested from the server with If-Modified-Since and If-None-Match HTTP headers.

I've created an example for the structure of this JSON file:

{
	"schema_version": "1"
	"internal_url": "https://example.com/blender-addon-index/"
	"addons": {
		"example_addon_one": {
			"source": "internal"
			"name": "Example Add-on One"
			"description": "Example Description"
			"author": "Author Name"
			"wiki_url": "http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Example_Add-on_One"
			"tracker_url": "http://developer.blender.org/maniphest/task/create/?project=id&type=Bug"
			"location": "Window > Menu > Submenu"
			"category": "Category"
			"version": {
				"1.3.3": {
					"blender": "2.76.0"
					"support": "official"
					"filename": "1.3.3.py"
				}
				"1.4.0": {
					"blender": "2.77.0"
					"support": "official"
					"filename": "1.4.0.py"
				}
			}
		}
		"example_addon_two": {
			"source": "internal"
			"name": "Example Add-on Two"
			"description": "Example Description"
			"author": "Author 1 Name, Author 2 Name"
			"wiki_url": "http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Example_Add-on_Two"
			"tracker_url": "http://developer.blender.org/maniphest/task/create/?project=id&type=Bug"
			"location": "Window > Menu > Submenu"
			"category": "Category"
			"version": {
				"2.0.2": {
					"blender": "2.76.0"
					"warning": "Warning Text"
					"support": "testing"
					"filename": "2.0.2.zip"
				}
				"2.0.3": {
					"blender": "2.76.0"
					"support": "community"
					"filename": "2.0.3.zip"
				}
				"2.1.0": {
					"blender": "2.77.0"
					"support": "community"
					"filename": "2.1.0.zip"
				}
			}
		}
		"example_addon_three": {
			"source": "external"
			"external_url": "https://example.net/my-addon/"
			"name": "Example Add-on Three"
			"description": "Example Description"
			"author": "Author Name"
			"wiki_url": "http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Example_Add-on_Three"
			"tracker_url": ""
			"location": "Window > Menu > Submenu"
			"category": "Category"
			"version": {
				"0.3.2": {
					"blender": "2.77.0"
					"warning": "Warning Text"
					"support": "testing"
					"filename": "0.3.2.zip"
				}
			}
		}
	}
}

This file would correspond to a file structure like the one proposed under Server-Side Storage.

If I'm going for a HTTP-based approach, what is the URL structure going to look like?

During GSoC at least, I plan to use the the below file structure:

index.json
example_addon_one/
	1.3.3.py
	1.4.0.py
example_addon_two/
	2.0.2.zip
	2.0.3.zip
	2.1.0.zip

What information needs to be communicated?

• A list of all add-ons registered on the proposed "Blender Add-on Index"
• Each available version of every add-on
• The Blender version (or multiple versions?) each add-on supports
• Dependencies (possibly): Which version of other add-on(s) each add-on requires
• Likely the add-on download itself

How am I going to handle missing or malformed requests?

Will also be decided once more basic things such as protocol are chosen.

Server-Side Storage

What will need to be stored on the server?

A list of all available add-ons, each available version, the version of Blender each works with, and possibly dependency info at the very least. The add-ons themselves (in .zip/.py form) will probably need to be stored on the server as well.

Ton would highly prefer not having to install new software on blender.org, and requested I avoid this. I plan to double-check with him on this, but I believe he mentioned he was open to hosting add-ons as .zip/.py for the manager to download.

How will it be stored? In a relational database like MySQL, PostgreSQL or SQLite? NoSQL database like MongoDB?

I think a database would be over-complicating things, and using a version control system like git would be preferable.

Client-Side Code

How will I structure the client-side Python library, such that it can work asynchronously, and Blender can query things like download status/progress?

Protocol and server-side questions are more important to answer first, so I'll answer this when I have a better idea of how those things will look.