verae-middleware/src/nats/connection.js

116 lines
3 KiB
JavaScript

/**
* @fileoverview NATS + JetStream connection lifecycle.
* @module nats/connection
*/
import { createDebugger } from '../debug/logger.js';
import { config } from '../config.js';
import { SUBJECTS, STREAMS } from './subjects.js';
const log = createDebugger('nats');
/** @type {import('nats').NatsConnection|null} */
let nc = null;
/** @type {import('nats').JetStreamClient|null} */
let js = null;
/** @type {import('nats').JetStreamManager|null} */
let jsm = null;
/**
* Connect to NATS and return JetStream handles.
*
* @param {string} [url=config.natsUrl]
* @returns {Promise<{ nc: import('nats').NatsConnection, js: import('nats').JetStreamClient, jsm: import('nats').JetStreamManager }>}
*/
export async function connectNats(url = config.natsUrl) {
if (!config.natsEnabled && process.env.NATS_FORCE_CONNECT !== '1') {
log.debug('connect skipped — NATS_ENABLED=false');
throw new Error('NATS is disabled (NATS_ENABLED=false)');
}
if (nc && js && jsm) {
return { nc, js, jsm };
}
log.info('connecting to NATS', { url });
const { connect } = await import('nats');
nc = await connect({ servers: url, name: 'verae-zapier-middleware' });
js = nc.jetstream();
jsm = await nc.jetstreamManager();
log.info('NATS connected', { url });
return { nc, js, jsm };
}
/** @returns {import('nats').NatsConnection|null} */
export function getNatsConnection() {
return nc;
}
/**
* Idempotently create JetStream streams required by this middleware.
*
* @param {import('nats').JetStreamManager} [manager]
* @returns {Promise<void>}
*/
export async function ensureStreams(manager) {
const m = manager ?? jsm;
if (!m) {
throw new Error('JetStream manager not available — call connectNats first');
}
/** @type {Array<{ name: string, subjects: string[] }>} */
const defs = [
{ name: STREAMS.ZAPIER_JOBS, subjects: [SUBJECTS.JOBS_WATCH] },
{ name: STREAMS.ZAPIER_EVENTS, subjects: [SUBJECTS.JOBS_EVENTS] },
{ name: STREAMS.ZAPIER_WEBHOOKS, subjects: [SUBJECTS.WEBHOOKS_DELIVER] },
];
for (const def of defs) {
try {
await m.streams.info(def.name);
log.debug('stream exists', { stream: def.name });
} catch {
await m.streams.add({
name: def.name,
subjects: def.subjects,
retention: 'limits',
storage: 'file',
max_age: 24 * 60 * 60 * 1e9, // 24h in ns
num_replicas: 1,
});
log.info('stream created', { stream: def.name, subjects: def.subjects });
}
}
}
/**
* Close the shared NATS connection if open.
* @returns {Promise<void>}
*/
export async function closeNats() {
if (!nc) {
log.debug('closeNats: no active connection');
return;
}
log.info('closing NATS connection');
await nc.drain();
nc = null;
js = null;
jsm = null;
}
/**
* @returns {import('nats').JetStreamClient|null}
*/
export function getJetStream() {
return js;
}
/**
* @returns {boolean}
*/
export function isNatsConnected() {
return Boolean(nc && !nc.isClosed());
}