Refactor to allow for multiple transports

conf/config.schema.json

@@ -10,6 +10,10 @@
         "isPublic": true
       }
     },
+    "transport": {
+      "description": "Mail transport to use",
+      "type": "string"
+    },
     "connectionUrl": {
       "description": "Connection URL for the SMTP service",
       "type": "string",

index.js

@@ -2,4 +2,5 @@
  * Email sending utilities
  * @namespace mailer
  */
+export { default as AbstractMailTransport } from './lib/AbstractMailTransport.js'
 export { default } from './lib/MailerModule.js'

lib/AbstractMailTransport.js

@@ -0,0 +1,30 @@
+import { App } from 'adapt-authoring-core'
+/**
+ * An abstract class which encompasses functions related to a single mail transport type
+ * @memberof mailer
+ */
+class AbstractMailTransport {
+  name;
+
+  /**
+   * Shortcut to retrieve mailer config values
+   * @param {string} key 
+   * @returns {String} the config value
+   */
+  getConfig (key) {
+    return App.instance.config.get(`adapt-authoring-mailer.${key}`)
+  }
+
+  /**
+   * Sends an email
+   * @param {MailData} data
+   */
+  async send (data) {}
+
+  /**
+   * Performs any useful tests to check transport is working correctly
+   */
+  async test () {}
+}
+
+export default AbstractMailTransport

lib/MailerModule.js

@@ -1,5 +1,8 @@
 import { AbstractModule } from 'adapt-authoring-core'
-import nodemailer from 'nodemailer'
+import AbstractMailTransport from './AbstractMailTransport.js'
+import AzureTransport from './transports/AzureTransport.js'
+import FilesystemTransport from './transports/FilesystemTransport.js'
+import SmtpTransport from './transports/SmtpTransport.js'
 /**
  * Mailer Module
  * @memberof mailer
@@ -19,15 +22,10 @@ class MailerModule extends AbstractModule {
      */
     this.connectionUrl = this.getConfig('connectionUrl')
     /**
-     * The Nodemailer SMTP transport instance
-     * @type {Nodemailer~Transport}
+     * Registered mail transports
+     * @type {Object}
      */
-    this.transporter = undefined
-
-    if (this.isEnabled) {
-      this.transporter = nodemailer.createTransport(this.connectionUrl)
-      await this.testConnection()
-    }
+    this.transports = {}
     // note we still enable the API route if mailer is disabled to allow for testing
     const [auth, server] = await this.app.waitForModule('auth', 'server')
     const router = server.api.createChildRouter('mailer')
@@ -43,18 +41,47 @@ class MailerModule extends AbstractModule {
       }
     })
     auth.unsecureRoute(`${router.path}/test`, 'post')
+
+    if (this.isEnabled) {
+      // add the standard transport
+      this.registerTransport(AzureTransport)
+      this.registerTransport(FilesystemTransport)
+      this.registerTransport(SmtpTransport)
+      this.app.onReady().then(() => this.initTransports())
+    }
   }
 
-  /**
-   * Checks the provided SMTP settings using nodemailer.verify.
-   * @return {Promise}
-   */
-  async testConnection () {
+  registerTransport (TransportClass) {
+    let t
     try {
-      await this.transporter.verify()
-      this.log('info', 'SMTP connection verified successfully')
+      t = new TransportClass()
+      this.transports[t.name] = t
     } catch (e) {
-      this.log('warn', `SMTP connection test failed, ${e}`)
+      this.log('error', `Failed to create transport, ${e}`)
+    }
+    if (!(t instanceof AbstractMailTransport)) {
+      this.log('error', 'Failed to create transport, not an instance of AbstractMailTransport')
+    }
+    if (!t.name) {
+      this.log('error', 'Failed to create transport, does not define a name')
+    }
+  }
+
+  getTransport() {
+    const transportName = this.getConfig('transport')
+    if(!this.transports[transportName]) {
+      throw new Error(`No transport with name ${transportName}`)
+    }
+    return this.transports[transportName]
+  }
+
+  async initTransports () {
+    const transport = this.getTransport()
+    try {
+      await transport.test()
+      this.log('info', `${transport.name} connection verified successfully`)
+    } catch (e) {
+      this.log('warn', `${transport.name} connection test failed, ${e}`)
     }
   }
 
@@ -79,7 +106,9 @@ class MailerModule extends AbstractModule {
       const jsonschema = await this.app.waitForModule('jsonschema')
       const schema = await jsonschema.getSchema('maildata')
       await schema.validate(data)
-      await this.transporter.sendMail(data)
+
+      await this.getTransport().send(data)
+
       this.log('info', 'email sent successfully')
     } catch (e) {
       throw this.app.errors.MAIL_SEND_FAILED.setData({ email: data.to, error: e })

lib/transports/AzureTransport.js

@@ -0,0 +1,48 @@
+import AbstractMailTransport from '../AbstractMailTransport.js'
+import { EmailClient, KnownEmailSendStatus } from '@azure/communication-email'
+/**
+ * Microsoft Azure Mail Transport
+ * @memberof mailer
+ * @extends {AbstractMailTransport}
+ */
+class AzureTransport extends AbstractMailTransport {
+  name = 'azure'
+
+  /** @override */
+  async send (data) {
+    const message = {
+      senderAddress: data.from,
+      content: {
+        subject: data.subject,
+        plainText: data.text,
+        html: data.html
+      },
+      recipients: {
+        to: [{ address: data.to }]
+      }
+    }
+    const client = new EmailClient(this.getConfig('connectionUrl'))
+    const poller = await client.beginSend(message)
+
+    if (!poller.getOperationState().isStarted) {
+      throw new Error('Poller was not started.')
+    }
+    let elapsedSecs = 0
+    const timeoutSecs = 10
+    while (!poller.isDone()) {
+      poller.poll()
+
+      await new Promise(resolve => setTimeout(resolve, 1000))
+      elapsedSecs++
+
+      if (elapsedSecs >= timeoutSecs) {
+        throw new Error('Polling timed out.')
+      }
+    }
+    if (poller.getResult().status !== KnownEmailSendStatus.Succeeded) {
+      throw poller.getResult().error
+    }
+  }
+}
+
+export default AzureTransport

lib/transports/FilesystemTransport.js

@@ -0,0 +1,23 @@
+import AbstractMailTransport from '../AbstractMailTransport.js'
+import { App } from 'adapt-authoring-core'
+import fs from 'fs/promises'
+import path from 'path'
+/**
+ * Local filesystem shim mail transport, will store mail data locally
+ * @memberof mailer
+ * @extends {AbstractMailTransport}
+ */
+class FilesystemTransport extends AbstractMailTransport {
+  name = 'filesystem'
+
+  /** @override */
+  async send (data) {
+    const dir = path.join(App.instance.getConfig('tempDir'), 'mailer')
+    try {
+      await fs.mkdir(dir)
+    } catch {}
+    return fs.writeFile(path.join(dir, `${Date.now()}.txt`), JSON.stringify(data, null, 2))
+  }
+}
+
+export default FilesystemTransport

lib/transports/SmtpTransport.js

@@ -0,0 +1,26 @@
+import AbstractMailTransport from '../AbstractMailTransport.js'
+import nodemailer from 'nodemailer'
+/**
+ * SMTP mail transport
+ * @memberof mailer
+ * @extends {AbstractMailTransport}
+ */
+class SmtpTransport extends AbstractMailTransport {
+  name = 'smtp'
+
+  createTransport () {
+    return nodemailer.createTransport(this.getConfig('connectionUrl'))
+  }
+
+  /** @override */
+  async send (data) {
+    return this.createTransport().sendMail(data)
+  }
+
+  /** @override */
+  async test () {
+    await this.createTransport().verify()
+  }
+}
+
+export default SmtpTransport

package.json

@@ -8,6 +8,7 @@
   "main": "index.js",
   "repository": "github:adapt-security/adapt-authoring-mailer",
   "dependencies": {
+    "@azure/communication-email": "^1.0.0",
     "nodemailer": "^6.9.9"
   },
   "peerDependencies": {