That is just *all kinds* of awesome.
-- brion
On Thu, Nov 5, 2015 at 1:47 PM, C. Scott Ananian cananian@wikimedia.org wrote:
Architecturally it may be desirable to factor our codebase into multiple independent services with clear APIs, but small wikis would clearly like a "single server" installation with all of the services running under one roof, as it were. Some options previously proposed have involved VM containers that bundle PHP, Node, MediaWiki and all required services into a preconfigured full system image. (T87774 https://phabricator.wikimedia.org/T87774)
This summit topic/RFC proposes an alternative: tightly integrating PHP/HHVM with a persistent server process running under node.js. The central service bundles together multiple independent services, written in either PHP or JavaScript, and coordinates their configurations. Running a wiki-with-services can be done on a shared node.js host like Heroku.
This is not intended as a production configuration for large wikis -- in those cases having separate server farms for PHP, PHP services, and JavaScript services is best: that independence is indeed the reason why refactoring into services is desirable. But integrating the services into a single process allows for hassle-free configuration and maintenance of small wikis.
A proof-of-concept has been built. The node package php-embed https://www.npmjs.com/package/php-embed embeds PHP 5.6.14 into a node.js (>= 2.4.0) process, with bidirectional property and method access between PHP and node. The package mediawiki-express https://www.npmjs.com/package/mediawiki-express uses this to embed MediaWiki into an express.js http://expressjs.com/ HTTP server. (Other HTTP server frameworks could equally well be used.) A hook in the ` LocalSettings.php` allows you to configure the mediawiki instance in JavaScript.
A bit of further hacking would allow you to fully configure the MediaWiki instance (in either PHP or JavaScript) and to dispatch to Parsoid (running in the same process).
*SUMMIT GOALS / FOR DISCUSSION*
- Determine whether this technology (or something similar) might be an
acceptable alternative for small sites which are currently using shared hosting. See T113210 https://phabricator.wikimedia.org/T113210 for related discussion.
- Identify and address technical roadblocks to deploying modular
single-server wikis (see below).
- Discuss methods for deploying complex wikitext extensions. For
example, the WikiHiero https://www.mediawiki.org/wiki/Extension:WikiHiero extension would ideally be distributed with (a) PHP code hooking mediawiki core, (b) client-side JavaScript extending Visual Editor, and (c) server-side JavaScript extending Parsoid. Can these be distributed as a single integrated bundle?
*TECHNICAL CHALLENGES*
- Certain pieces of our code are hardwired to specific directories
underneath mediawiki-core code. This complicates efforts to run mediawiki from a "clean tree", and to distribute piece of mediawiki separately. In particular:
- It would be better if the `vendor` directory could (optionally) live outside the core mediawiki tree, so it could be distributed
separately from the main codebase, and allow for alternative package structures. - Extensions and skins would benefit from allowing a "path-like" list of directories, rather than a single location underneath the core mediawiki tree. Extensions/skins could be distributed as separate packages, with a simple hook to add their locations to the search path. - Tim Starling has suggested that when running in single-server mode, some internal APIs (for example, between mediawiki and Parsoid) would be better exposed as unix sockets on the filesystem, rather than as internet domain sockets bound to localhost. For one, this would be more "secure by default" and avoid inadvertent exposure of internal service APIs.
- It would be best to define a standardized mechanism for "services" to
declare themselves & be connected & configured. This may mean standard ro utes on a single-server install (`/w` and `/wiki` for core, `/parsoid` for parsoid, `/thumb` for the thumbnailer service, etc), standard ports for each service (with their own http servers), or else standard locations for unix sockets.
- Can we leverage some of the various efforts to bridge composer and npm
(for example https://github.com/eloquent/composer-npm-bridge), so we don't end up with incompatible packaging?
Phabricator ticket: https://phabricator.wikimedia.org/T114457
Download the code for mediawiki-express and play with it a bit and let's discuss! --scott
-- (http://cscott.net) _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l