Email handler

This email handler application sends an email using the SendGrid system using the MailGun system as a failover. The RESTful API endpoint /email requires a body to be sent with the following JSON structure. The cc and bcc fields are optional. All other fields are required

{
	"to": [<string>, <string>, ...],
	"cc": [<string>, <string>, ...],
	"bcc": [<string>, <string>, ...],
	"subject": <string>,
	"text": <string>,
	"from": <string>
}

Validation

• Todo: Replace with validate.js https://validatejs.org/
• The API will return a 400 status code if any of the required parameters of to, subject, text and from are missing.
• The API will return a 400 status code if the to, cc or bcc paramaters are not valid arrays of email addresses.
• The API uses the validator npm package to confirm valid email structure

Error handling

The application checks for an invalid JSON body using a custom express.js middleware function that checks for a 400 error status on every request.

Install and Setup

Mail configuration

It is necessary to have an .env file containing various API keys for the SendGrid and Mailgun packages, as shown below. This file is not added to source control and is required to be manually created in a test environment and in production

PORT = 8080
MAILGUN_DOMAIN = <mailgun-domain>
MAILGUN_API_KEY = <mailgun-api-key>
SENDGRID_API_KEY = <send-grid-api-key>

Server startup

Perform a git clone and npm install in a remote server and enter the following command to execute the node.js listener so that it can respond to API requests

npm run start

Endpoint

A cURL request can be performed to test the /email endpoint as follows

curl -X POST \
  http://138.68.247.201:8080/email \
  -H 'Accept: */*' \
  -H 'Accept-Encoding: gzip, deflate' \
  -H 'Cache-Control: no-cache' \
  -H 'Connection: keep-alive' \
  -H 'Content-Length: 175' \
  -H 'Content-Type: application/json' \
  -H 'Host: 138.68.247.201:8080' \
  -H 'Postman-Token: c772241a-7fc9-488b-9ac4-b23c02e1deac,02baf092-1cf0-4522-bcca-1f56aabe1cf2' \
  -H 'User-Agent: PostmanRuntime/7.18.0' \
  -H 'cache-control: no-cache' \
  -d '{
	"to": ["james.ioppolo@gmail.com"],
	"cc": ["james.ioppolo@gmail.com"],
	"bcc": [],
	"subject": "subject line",
	"text": "text message",
	"from": "james.ioppolo@gmail.com"
}'

Tests

Execute the following command to run the unit tests in the project:

npm run test