Series

Kubernetes: A hybrid Calico and Layer 2 Bridge+DHCP network using Multus

This article is part of the Home Lab series.

Previously in my Home Lab series, I described how my home lab Kubernetes clusters runs with a DHCP CNI–all pods get an IP address on the same layer 2 network as the rest of my home and an IP from DHCP. This enabled me to run certain software that needed this like Home Assistant which wanted to be able to do mDNS and send broadcast packets to discover device.

However, not all pods actually needed to be on the same layer 2 network and lead to a few situations where I ran out of IP addresses on the DHCP server and couldn’t connect any new devices until reservations expired:

How to gain access to a RKE2 cluster without Rancher when the CNI doesn't work

In my previous post where I outlined challenges that I’ve encountered with Rancher. As part of the feedback to that I ended up having to rebuild one of my clusters. I took that time to try out RKE2 and K3s for my home lab. In this home lab, I use a custom CNI based on the official Bridge and DHCP IPAM CNIs (Read more) to enable my smart home software (HomeAssistant) to communicate with other devices on the same Layer 2 domain.

Defensive Coding: Stop using your storage models everywhere

How to make your system robust against your worst nightmare–your future self

In this post, I talk about some strategies that I’ve learned to simplify class structures in Java services that load and persist data into data stores like DynamoDB or RDS at the same time making the codebase safer.

As always, my opinions are my own.

At Amazon, I ended up joining two teams that were suffering under the technical debt. Each time, I was asked to spend some time understanding why the products were unstable and users were encountering frequent bugs. In one system, responsible for managing critical metadata about products in the catalog, was experiencing problems where users were reporting that they’d randomly lose data.

Plot your health with Samsung Health and Pandas

Artwork by Sami Lee.

For the last 5+ years, I’ve been tracking my various aspects of my personal health using Samsung Health. It helps track weight, calories, heart rate, stress, and exercise and stores all of it in the app.

However, the app only gives some basic high level charts and insights. Luckily, it enables you to export your personal data into CSV files that you can then import into your tool of choice and perform any kind of analytics. In this post, I’m going to show how to export it all, then load it into Zeppelin and some sample Pandas queries that’ll enable you to start building more complex queries yourself.

Accurate, Local Home Energy Monitoring: Part 1 - Hardware

This article is part of the Home Energy Monitoring series.

Ever wondered where the energy is going in your house and know exactly when and which circuit is consuming the most electricity? How much is your air conditioning unit costing you each month in kWh?

Home energy monitors are devices that you can use to monitor how much energy you’re using at any given point in time. You can use them to figure out how much each device or circuit you’re using overnight vs the day. If you have differing energy costs at the day vs night, you can use them to ensure devices run at lower cost time of day, you can use it to as part of a smart home automation to automatically notify you when your washing machine is done, or even identify when you need to upgrade a circuit because your server room is pulling too much.