Chiwai Chan's Blog

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Cloud

Maintain a Prefix List of EC2 Private IP Addresses using EventBridge

AWS VPC customer-managed prefix list is a great feature to have in a tool box as it provides the ability to track and maintain a list of CIDR block values, that can be referenced by other AWS Networking component’s in their rules and tables. Each Prefix List supports either IPv4 or IPv6 based addresses, and […]

Work-around for cross-account Transit Gateway Security Group Reference

Have you ever tried to create a Security Group with a Source or Destination rule that references another Security Group? how about referencing a Security Group from another AWS account to allow ingress network traffic over a Transit Gateway architecture? if this question peaked your interest then you should keep reading. In this blog we […]

Breaking Down Monolithic Subnets

As my knowledge and experience of Cloud networking grew from designing network architectures over time and also more of lately from reviewing client network architectures, I’ve come to realise and appreciate the need to designing a proper network architecture that includes the long-term considerations, as early as possible – especially before a projects begins and […]

Swiss Cheese Network Security: Factorising Security Group Rules into NACLs and Security Group Rules

Introduction Lately I’ve been doing some networking configuration reviews for some of the projects I’ve been put on; to balance out the #crazycatlady blogs I’ll be blogging about some network patterns and components that don’t often get much attention or get used at all in the pipeline of blogs. Today I’ll be talking about Network […]

Smart Cat Feeder – Part 4

This is the Part 4 and final blog of the series where I detail my journey in learning to build an IoT solution. Please have a read of my previous blogs to get the full context leading up to this point before continuing. Part 1: I talked about setting up a Seeed AWS IoT Button […]

Hosting multiple subsites under a serverless website instance

Introduction Recently, I was tasked with coming up with a solution for a single website instance to host various pockets of documentations scattered across a growing number of Git repositories; each repository hosted documentation for a specific subject domain written in Markdown format – you may have come across README.md files all over the internet […]

Smart Cat Feeder – Part 2

The source code for this blog can be found in my Github repository: https://github.com/chiwaichan/aws-iot-cat-feeder. This repository only includes the source code for the solution implemented up to this stage/blog in the project. In the end I decided to go with the Seeed Studio XIAO ESP32C3 implementation of the ESP32 micro-controller for $4.99 (USD). I also […]

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