wmantly
fe71ec1bcc
The announcer half of AGENT_LOCAL_DISCOVERY_SPEC.md / MULTI_SITE_SPEC.md Appendix B -- advertises which public hostnames this site fronts (and at what local IP) via mDNS, so a theta-agent on the same LAN segment with prefer_local_directory enabled can skip the relay/WAN path. Opt-in via THETA_LOCAL_DISCOVERY_HOSTS (comma-separated); no-op if unset, so this changes nothing for an install that doesn't configure it. Only ever advertises which hostnames map to which local IP -- no identity/ trust information -- consistent with the hard rule on the listening side (theta-agent) that local-discovery may change DNS resolution but must never touch certificate validation. Verified end-to-end against the real theta-agent Go binary: announce, discover, apply, and clean revert on disappearance all confirmed working over real multicast between two containers.
57 lines
1.8 KiB
JavaScript
57 lines
1.8 KiB
JavaScript
'use strict';
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// mDNS local-discovery announcer (MULTI_SITE_SPEC.md Appendix B). Advertises
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// this site's local presence so an agent on the same LAN segment (with
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// prefer_local_directory enabled -- see theta-agent's local_discovery.go)
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// can skip the relay/WAN path and talk to the local instance directly.
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//
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// What gets announced is deliberately just "which public hostnames does
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// this site front, and at what local IP" -- nothing about identity or
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// trust. The listening side never weakens certificate validation based on
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// this; it only ever changes DNS resolution (see the hard rule documented
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// in theta-agent's local_discovery.go).
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const SERVICE_TYPE = 'theta-suite'; // -> _theta-suite._tcp, matches theta-agent's mdnsServiceName
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function announcedHosts() {
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return (process.env.THETA_LOCAL_DISCOVERY_HOSTS || '')
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.split(',')
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.map((h) => h.trim())
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.filter(Boolean);
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}
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let bonjourInstance = null;
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let publishedService = null;
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async function startMdnsAnnounce() {
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const hosts = announcedHosts();
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if (hosts.length === 0) {
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console.log('[mdns-announce] THETA_LOCAL_DISCOVERY_HOSTS not set -- nothing to announce, skipping');
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return;
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}
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const { Bonjour } = require('bonjour-service');
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bonjourInstance = new Bonjour(undefined, (err) => {
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console.error('[mdns-announce] bonjour-service error:', err.message);
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});
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publishedService = bonjourInstance.publish({
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name: `theta-suite-${process.env.SITE_SLUG || 'site'}`,
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type: SERVICE_TYPE,
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port: Number(process.env.PORT) || 80,
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txt: { hosts: hosts.join(','), site: process.env.SITE_SLUG || '' }
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});
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console.log(`[mdns-announce] announcing on the local network: ${hosts.join(', ')}`);
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}
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function stopMdnsAnnounce() {
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if (bonjourInstance) {
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bonjourInstance.destroy();
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bonjourInstance = null;
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publishedService = null;
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}
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}
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module.exports = { startMdnsAnnounce, stopMdnsAnnounce };
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