The current storage format of search is that each mediawiki page is a document. Wrangling external things into this format might technically be possible, but would be a bit of work.

As I understand it, Discourse will output .json if you ask it to. And Elasticsearch only cares about json. So wouldn't the work be to create a new index in Elasticsearch that consumes the .json available from Discourse? (I haven't done this, so I don't know the particulars)

As a poor man's substitute we could just add a "search on Discourse" button to the search page (from a default-on gadget, probably).

Sorry, I had missed / forgotten this request when creating a duplicated one. I took the liberty of editing the description to explain possible use cases better.

I think the reference to take is https://www.mediawiki.org/wiki/Cross-wiki_Search_Result_Improvements/Design

I don't know what is the state of the art of displaying related search results, but as a user I think I remember seeing results from other projects in a separate column. The equivalent here would be to see Discourse results in a separate column when showing the results of a query in MediaWiki.org.

In T190560#4846240, @Qgil wrote:

[...] I don't know what is the state of the art of displaying related search results, but as a user I think I remember seeing results from other projects in a separate column. The equivalent here would be to see Discourse results in a separate column when showing the results of a query in MediaWiki.org.

Yup. example search on enwiki (works the same in Private window) shows some sister projects in a sidebar.

This task is likely to be morphed for Space.

I think a more fruitful starting place for this sort of thing would be doc.wikimedia.org - its probably simpler as a semi static thing, and i think at these early stages it has more relavent info than discourse does at present (although ideally search would search all the things)

Bawolff's point stands: there are several Wikimedia-related static websites nowadays.

OK, can these other possible search integrations be filed in separate tasks? Each integration has its reasons. I guess some work will be common to all of them, and some work will have to be specific.

The original use case was integrating discourse-mediawiki.wmflabs.org content into mediawiki.org search. That was sort of hypothetical, in the the effort to make discourse-mediawiki a truly active and useful support channel has not been put in yet, and integrating it in search would probably not be worth the effort. Since then the main use case has shifted to integrating discuss-space.wmflabs.org content into some unspecified wiki search...

...which brings me to my main point, there isn't necessarily a one Discourse -> one wiki relationship with Space so this might need further thought. Consider that there is no way to disable sister project searches the way you can disable e.g. searching talk pages, so low-relevance results will be confusing. I think 1) there should be a way to match categories to wikis (e.g. the huwiki Space category should be surfaced on Hungarian Wikipedia but not elsewhere; the Tremendous Wiktionary UG category should only show on wiktionaries); 3) there should be a way to suppress categories (especially events, as there's a lot of them and text-based search is not particularly useful for them); 3) search should only show discussions in the right language (so this might depend on T226721: Multilingual Wikimedia Space getting a little more advanced).

In T190560#6442800, @Aklapper wrote:

Hence boldly declining this task as there is no use case for Wikimedia currently.

Makes sense, thank you.

However, I'll note that this objective (and several others) would be reached if the discussions were imported into the wikis from Discourse.