WiP on mailers

lib/mailers.js

@@ -0,0 +1,232 @@
+'use strict';
+
+const log = require('npmlog');
+const config = require('config');
+
+const Handlebars = require('handlebars');
+const util = require('util');
+const nodemailer = require('nodemailer');
+const aws = require('aws-sdk');
+const openpgpEncrypt = require('nodemailer-openpgp').openpgpEncrypt;
+const sendConfigurations = require('../models/send-configurations');
+
+const contextHelpers = require('./context-helpers');
+const settings = require('../models/settings');
+const tools = require('./tools');
+const htmlToText = require('html-to-text');
+
+const bluebird = require('bluebird');
+
+const _ = require('./translate')._;
+
+Handlebars.registerHelper('translate', function (context, options) { // eslint-disable-line prefer-arrow-callback
+    if (typeof options === 'undefined' && context) {
+        options = context;
+        context = false;
+    }
+
+    let result = _(options.fn(this)); // eslint-disable-line no-invalid-this
+
+    if (Array.isArray(context)) {
+        result = util.format(result, ...context);
+    }
+    return new Handlebars.SafeString(result);
+});
+
+const transports = new Map();
+
+async function getOrCreateMailer(sendConfiguration) {
+    if (!sendConfiguration) {
+        sendConfiguration = sendConfigurations.getSystemSendConfiguration();
+    }
+
+    const transport = transports.get(sendConfiguration.id) || await _createTransport(sendConfiguration);
+    return transport.mailer;
+}
+
+function invalidateMailer(sendConfiguration) {
+    transports.delete(sendConfiguration.id);
+}
+
+
+
+
+async function _sendMail(transport, mail, template) {
+    if (!mail.headers) {
+        mail.headers = {};
+    }
+    mail.headers['X-Sending-Zone'] = 'transactional';
+
+    const htmlRenderer = await tools.getTemplate(template.html);
+
+    if (htmlRenderer) {
+        mail.html = htmlRenderer(template.data || {});
+    }
+
+    const preparedHtml = await tools.prepareHtml(mail.html);
+
+    if (prepareHtml) {
+        mail.html = prepareHtml;
+    }
+
+    const textRenderer = await tools.getTemplate(template.text);
+
+    if (textRenderer) {
+        mail.text = textRenderer(template.data || {});
+    } else if (mail.html) {
+        mail.text = htmlToText.fromString(mail.html, {
+            wordwrap: 130
+        });
+    }
+
+    let tryCount = 0;
+    const trySend = (callback) => {
+        tryCount++;
+        transport.sendMail(mail, (err, info) => {
+            if (err) {
+                log.error('Mail', err);
+                if (err.responseCode && err.responseCode >= 400 && err.responseCode < 500 && tryCount <= 5) {
+                    // temporary error, try again
+                    log.verbose('Mail', 'Retrying after %s sec. ...', tryCount);
+                    return setTimeout(trySend, tryCount * 1000);
+                }
+                return callback(err);
+            }
+            return callback(null, info);
+        });
+    };
+
+    const trySendAsync = bluebird.promisify(trySend);
+    return await trySendAsync();
+}
+
+
+async function _createTransport(sendConfiguration) {
+    const mailerSettings = sendConfiguration.mailer_settings;
+    const mailerType = sendConfiguration.mailer_type;
+    const configItems = await settings.get(contextHelpers.getAdminContext(), ['pgpPrivateKey', 'pgpPassphrase']);
+
+    const existingTransport = transports.get(sendConfiguration.id);
+
+    let existingListeners = [];
+    if (existingTransport) {
+        existingListeners = existingTransport.listeners('idle');
+        existingTransport.removeAllListeners('idle');
+        existingTransport.removeAllListeners('stream');
+        existingTransport.checkThrottling = null;
+    }
+
+    const logFunc = (...args) => {
+        const level = args.shift();
+        args.shift();
+        args.unshift('Mail');
+        log[level](...args);
+    };
+
+
+    let transportOptions;
+
+    if (mailerType === sendConfigurations.MailerType.GENERIC_SMTP || mailerType === sendConfigurations.MailerType.ZONE_MTA) {
+        transportOptions = {
+            pool: true,
+            host: mailerSettings.hostname,
+            port: mailerSettings.port || false,
+            secure: mailerSettings.encryption === 'TLS',
+            ignoreTLS: mailerSettings.encryption === 'NONE',
+            auth: mailerSettings.useAuth ? {
+                user: mailerSettings.user,
+                pass: mailerSettings.password
+            } : false,
+            debug: mailerSettings.logTransactions,
+            logger: mailerSettings.logTransactions ? {
+                debug: logFunc.bind(null, 'verbose'),
+                info: logFunc.bind(null, 'info'),
+                error: logFunc.bind(null, 'error')
+            } : false,
+            maxConnections: mailerSettings.maxConnections,
+            maxMessages: mailerSettings.maxMessages,
+            tls: {
+                rejectUnauthorized: !mailerSettings.allowSelfSigned
+            }
+        };
+
+    } else if (mailerType === sendConfigurations.MailerType.AWS_SES) {
+        const sendingRate = mailerSettings.throttling / 3600;  // convert to messages/second
+
+        transportOptions = {
+            SES: new aws.SES({
+                apiVersion: '2010-12-01',
+                accessKeyId: mailerSettings.key,
+                secretAccessKey: mailerSettings.secret,
+                region: mailerSettings.region
+            }),
+            debug: mailerSettings.logTransactions,
+            logger: mailerSettings.logTransactions ? {
+                debug: logFunc.bind(null, 'verbose'),
+                info: logFunc.bind(null, 'info'),
+                error: logFunc.bind(null, 'error')
+            } : false,
+            maxConnections: mailerSettings.maxConnections,
+            sendingRate
+        };
+
+    } else {
+        throw new Error('Invalid mail transport');
+    }
+
+    const transport = nodemailer.createTransport(transportOptions, config.nodemailer);
+
+    transport.use('stream', openpgpEncrypt({
+        signingKey: configItems.pgpPrivateKey,
+        passphrase: configItems.pgpPassphrase
+    }));
+
+    if (existingListeners.length) {
+        log.info('Mail', 'Reattaching %s idle listeners', existingListeners.length);
+        existingListeners.forEach(listener => transport.on('idle', listener));
+    }
+
+    let checkThrottling;
+
+    if (mailerType === sendConfigurations.MailerType.GENERIC_SMTP || mailerType === sendConfigurations.MailerType.ZONE_MTA) {
+        let throttling = mailerSettings.throttling;
+        if (throttling) {
+            throttling = 1 / (throttling / (3600 * 1000));
+        }
+
+        let lastCheck = Date.now();
+
+        checkThrottling = function (next) {
+            if (!throttling) {
+                return next();
+            }
+            let nextCheck = Date.now();
+            let checkDiff = (nextCheck - lastCheck);
+            if (checkDiff < throttling) {
+                log.verbose('Mail', 'Throttling next message in %s sec.', (throttling - checkDiff) / 1000);
+                setTimeout(() => {
+                    lastCheck = Date.now();
+                    next();
+                }, throttling - checkDiff);
+            } else {
+                lastCheck = nextCheck;
+                next();
+            }
+        };
+    } else {
+        checkThrottling = next => next();
+    }
+
+    transport.mailer = {
+        checkThrottling,
+        sendMail: async (mail, template) => await _sendMail(transport, mail, template)
+    };
+
+    transports.set(sendConfiguration.id, transport);
+    return transport;
+}
+
+module.exports = {
+    getOrCreateMailer,
+    invalidateMailer
+};