Basic support for Mosaico-based email templates.

lib/senders.js

@@ -1,5 +1,50 @@
 'use strict';
 
+const fork = require('child_process').fork;
+
+const config = require('config');
+const log = require('npmlog');
+const workers = new Set();
+
+function spawn(callback) {
+    let processes = Math.max(Number(config.queue.processes) || 1, 1);
+    let spawned = 0;
+    let returned = false;
+
+    if (processes > 1 && !config.redis.enabled) {
+        log.error('Queue', '%s processes requested but Redis is not enabled, spawning 1 process', processes);
+        processes = 1;
+    }
+
+    let spawnSender = function () {
+        if (spawned >= processes) {
+            if (!returned) {
+                returned = true;
+                return callback();
+            }
+            return false;
+        }
+
+        let child = fork(__dirname + '/../services/sender.js', []);
+        let pid = child.pid;
+        workers.add(child);
+
+        child.on('close', (code, signal) => {
+            spawned--;
+            workers.delete(child);
+            log.error('Child', 'Sender process %s exited with %s', pid, code || signal);
+            // Respawn after 5 seconds
+            setTimeout(() => spawnSender(), 5 * 1000).unref();
+        });
+
+        spawned++;
+        setImmediate(spawnSender);
+    };
+
+    spawnSender();
+}
+
 module.exports = {
-    workers: new Set()
+    workers,
+    spawn
 };