Follow-up to #699/#700/#702 — the OG SSR handler existed but three link
shapes never reached it behind the frontend nginx:
- Branded short URLs (/s/<slug>, #702) had NO nginx location, so they fell
through to the SPA — which has no /s/ route. Dead for humans (no 302
redirect) and crawlers (no OG). Add an ^~ /s/ proxy to the backend, whose
/s/:shortSlug route already handles both.
- Slideshow links (/gallery/<slug>/show/<token>) have TWO extra path
segments; the crawler-detect location regex allowed only one, so they
never rewrote to /og and got generic site-wide OG. Widen to {0,2} extra
segments (quoted regex — the braces would otherwise be parsed as nginx
config delimiters). client-access still matches (its token is in ?query,
one path segment).
- Viber's preview fetcher wasn't in either UA list, so Viber shares showed
no preview. Add it to nginx + SOCIAL_CRAWLER_PATTERNS (kept in sync).
Verified end-to-end: nginx -t passes; a live nginx+mock-backend harness
confirms /s/ proxies to the backend, slideshow + Viber + share-token +
client-access crawler UAs all rewrite to /og/gallery/<slug>, and browsers
still get the SPA. Backend isSocialCrawler test extended for Viber.
Paul Nothaft
0dffe0ce92