Seamless Email Notifications for WordPress via ROS 2 Microservices

Introduction¶

At ShitOps, we are constantly pushing the boundaries of technological innovation to solve common problems in unique ways. Recently, we tackled the challenge of delivering WordPress email notifications with unprecedented reliability, scalability, and modularity. Our team designed an elaborate multi-layered microservices architecture leveraging ROS 2, Apache Kafka, Kubernetes, and Terraform, integrating ROS 2's DDS communications with WordPress's PHP ecosystem in a completely novel way.

In this post, I will walk you through our engineered solution that ensures every email notification from WordPress is processed, tracked, and delivered flawlessly through an intricate web of ROS 2 microservices.

The Problem¶

WordPress' native email system often suffers from reliability issues, insufficient monitoring, and lack of scalability. At ShitOps, our WordPress instances require a robust solution to:

• Guarantee delivery of crucial emails such as password resets, user notifications, and admin alerts.

• Provide real-time monitoring and metrics of email status.

• Enable seamless scaling to millions of users without downtime or delays.

• Achieve modularity and fault tolerance by isolating components.

The Solution Overview¶

To achieve these goals, we introduced ROS 2 (Robot Operating System 2) into the pipeline, leveraging its DDS (Data Distribution Service) built-in communication middleware for distributed message passing.

Our architecture utilizes:

• A ROS 2 node running as a microservice within Kubernetes that acts as a WordPress listener.

• Apache Kafka for buffering and streaming email events.

• ROS 2 nodes dedicated to email templating, SMTP server interfacing, and monitoring.

• Terraform scripts to provision infrastructure as code.

Architecture Details¶

The WordPress plugin publishes email requests as JSON messages via a REST endpoint, which a ROS 2-based microservice subscribes to via a DDS message bridge.

This microservice then forwards the email event to Kafka, ensuring durability.

Separate ROS 2 consumer nodes subscribe to the Kafka topic, process the email templates, and pass finalized emails to an SMTP ROS 2 microservice.

Each step is encapsulated as a ROS 2 node to maintain modularity and high observability.

Detailed Flowchart¶

Implementation Details¶

ROS 2 Listener Node¶

Written in C++ with the rclcpp library, this node subscribes to a DDS topic that reflects WordPress emails posted via HTTP REST. It translates HTTP JSON requests into ROS 2 messages.

Kafka Integration¶

We leveraged the rclcpp Apache Kafka bridge to communicate between ROS 2 and Kafka. This setup enables distributed buffering, replay, and fault-tolerance in our email pipeline.

Email Template Node¶

A Python-based ROS 2 node using Jinja2 templating consumes email events from Kafka and produces customized HTML or plain text emails.

SMTP Node¶

Implemented in C++ again for performance, this ROS 2 node connects securely to our SMTP server cluster, sends emails, and publishes delivery success or failure events.

Monitoring Node¶

Using ROS 2's built-in diagnostics framework, the monitoring node consumes email status events and pushes detailed metrics dashboards to WordPress via REST callbacks.

Infrastructure as Code¶

All Kubernetes clusters, ROS 2 microservices, and Kafka clusters are declared in Terraform modules for consistency, repeatability, and scalability.

Conclusion¶

Employing ROS 2 as the backbone for WordPress email notifications allowed us to build an email delivery system that is fault-tolerant, scalable, and highly modular. The integration with Kafka and Kubernetes makes the system production-ready for massive scale.

This solution embodies ShitOps' ethos of architecting modern engineering marvels to tackle everyday challenges.

Feel free to reach out for detailed repositories, Terraform scripts, and ROS 2 package documentation in upcoming blog posts.