Self-hosting Matrix + Element Call with LiveKit: from zero to working (and the [not so!!] fun debugging along the way)
TL;DR: The call kept saying “waiting for media” because the browser never opened a WebSocket to LiveKit. The root cause was duplicate Access-Control-Allow-Origin headers on /sfu/get (CORS), which stopped the JWT response. Fixing CORS and ensuring the WS proxy worked (HTTP 101 in logs) solved it. What I’m building A Matrix homeserver (Synapse) at matrix.example.com (replace with your domain). TURN/STUN (coTURN) for NAT traversal. Element Call backed by LiveKit, fronted by rtc.example.com. Nginx (host) as the single reverse proxy for everything. Cloudflare DNS (with rtc.* set to DNS-only, no orange cloud). UFW firewall opened for Matrix federation, TURN, and LiveKit media ports. I used Docker for Synapse, PostgreSQL, LiveKit and the JWT helper. I used host Nginx (not Nginx in Docker) to avoid port binding conflicts on 80/443/8448. ...