Build a Serverless Email Notification Service

💧 Watch Drop: Your Email Driven TV Notification Service

🚀 Overview

Watch Drop is a serverless, personalised notification service that keeps you updated on your favorite TV shows. No more missing new episodes or releases

Once subscribed to a title, Watch Drop automatically creates you an account and checks for new content daily, then sends you an email alert when a new episode becomes available to stream.

This project is built leveraging AWS serverless services for efficiency and scalability, integrating with The Movie Database (TMDB) for comprehensive content information and using emails essentially as a CLI interface.

🧠 How It Works

Research what show you want to get alerts for in TMDB

Copy the url

Send an email to subscribe@watchdrop.org with the heading add <https://www.themoviedb.org/tv/83867-andor>

You are now subscribed and if a new episode airs, you will receive an email alert to the address you sent from

To unsubscribe from a show, simply send an email with remove instead of add

To unsubscribe from everything, send an email with nuke account

Tech Stack

Route 53 to provide Domain name, TXT, MX and 3 CNAME records

SES Simple Email Service to receive and send emails to AWS

Lambda 3 Serverless functions, email_processor, tmdb_scanner, ses-sender

IAM For Lambda and SES role utilization, least privilege

Secrets Manager to store credentials for TMDB API

DynamoDB Store records of users with their movie/show preferences - Also state-lock

S3 State-lock storage

Python For writing Lambda functions

Terraform All resources orchestrated using Hashicorp Terraform IaC

🚀 Do It Yourself

Watch Drop is built with an entirely Infrastructure As Code approach so with a few simple steps you can have your own custom version up and running in your own AWS account

Note: You will need to buy a domain costing about $14usd+ per year

Prerequisites

Download and install Git

Setup an AWS account

Download and install the AWS Command Line Interface (CLI)

Setup AWS Credentials on your machine

Download and install Terraform

Setup a TMDB Account

Apply for TMDB API Key

Optional - If you want to run code locally:

Download and install Python 3.9 or above

Install pip

Initialization

Open your terminal and clone this repository


git clone <https://github.com/OperationFman/Watch-Drop.git>

Rename if desired and navigate to the /iac directory e.g:

Create a new file called terraform.tfvars

Open the file then paste this starter configuration, in following steps we will replace each value with your own data. Save the file


project_title                  = "WatchDrop"
project_title_lowercase        = "watch-drop"
ses_domain                     = "watchdrop.org"
ses_receiving_email_address    = "subscribe@watchdrop.org"
owner                          = "Franklin Moon"
aws_account_number             = "123456781234"
aws_account_region             = "ap-southeast-2"
tmdb_api_key_value             = "eyBLAHBLAHBLAH"
schedule_cron                  = "cron(0 8 * * ? *)"
environment                    = "Production"

Configuration

Update basic variables

Inside terraform.tfvars update these values:

project_title

project_title_lowercase

owner (you)

aws_account_number (Found in the top right of the AWS console)

aws_account_region (Wherever you choose, be consistent from now on)

Optional: You can leave the environment and schedule_cron as-is if you are happy with them

Get TMDB API Key

Open TMDB API, if your application has been approved, generate a key here

Copy and paste the key in terraform.tfvars tmdb_api_key_value field:


tmdb_api_key_value = "YOURKEYGOESHERE"

Buy a domain

On the left side panel, select 'Registered domains' then click 'Register domains'

Search for a new domain name you'd like to use and select the option you want at a reasonable price

Complete the purchase

Add the domain name to your terraform.tfvars file, e.g


ses_domain                  = "yournewdomain.com"
ses_receiving_email_address = "subscribe@yournewdomain.com"

Setup State-lock

In AWS Console, open S3

Create a new bucket with name <YOUR-PROJECT-NAME>-terraform-state-<YOUR-AWS-ACCOUNT-ID>

Keep all settings as default, create

Next, open DynamoDB and make sure you're in the region you want to use going forward (Top right corner) e.g ap-southeast-2

Click Create Table:

Name <YOUR-PROJECT-NAME>-terraform-locks

Partition Key LockID (String)

Open provider.tf in the /iac folder and update the bucket, key and dynamodb table values to match what you just created


  backend "s3" {
    bucket         = "<YOUR-PROJECT-NAME>-terraform-state-<YOUR-AWS-ACCOUNT-ID>"
    key            = "<YOUR-PROJECT-NAME-IN-LOWERCASE>/terraform.tfstate"
    region         = "ap-southeast-2"
    dynamodb_table = "<YOUR-PROJECT-NAME>-terraform-locks"
    encrypt        = true
  }

Note: Make sure the start of the key value matches what you put in terraform.tfvars project_title_lowercase

Update Email Content

Update the wording inside /lambdas/email_processor/responses.py and /lambdas/tmdb_scanner/aired_alert.py

Here you can customize the design of any emails sent to your users inbox

Running IaC

Note: Before running the IaC, ensure your new Route 53 domain is active. Open Route 53 in AWS S3, if the domain says inactive, keep waiting for DNS propagation (should take several minutes but up-to 24 hours)

In your terminal from the /iac folder:


terraform init


terraform plan

Note what new cloud resources will be created


terraform apply

This command will provision all your core AWS resources: DynamoDB table, IAM roles/policies, Lambda functions and crucially, it will automatically configure your SES domain verification, DKIM, and MX records directly in Route 53

Exit Sandbox Mode

Note, by default your SES account will be in Sandbox mode which means you can only send/receive emails to verified email addresses (You can add more verified email address in the AWS SES Console under 'identities')

In your AWS Console, Open AWS SES (Simple Email Service)

Open the 'get set up' menu on the left side

Click 'Request production access' and fill out the form

Testing

Send an email to the @subscribe address, e.g

Receiver:


subscribe@<your-project-name>.com

Email header:


add <https://www.themoviedb.org/tv/83867-andor>

Note the new show in the DynamoDB Subscription table in AWS

You should now receive an alert at UTC+8

Watch Drop - Serverless Email Notifications