Author: admin

  • How to Query in MongoDB and Group by Date

    TL;DR: Here’s a quick example to query MongoDB documents created this year(2023) and group them by date, ie. how many my_doc were created today, yesterday, the day before yesterday, etc. The following statement works in a MongoDB client such as mongosh. Then here’s an equivalent example to do it with MongoEngine in Python: Since I…

  • New Recipes Learned!

    Some after thoughts: 🙂

  • A Free Unlimited Wordle Spinoff Running in Telegram

    It’s been a while and this game I built is quite stable now. A few things about this game(I called it word squad): Feel free to join https://t.me/+nGN2rDrGBJExY2U1 for a spin or use the QR below: UPDATE: 6-letter games are now open, user /game6 to start one! 🙂

  • Cloud SQL MySQL: Best Password is No Password

    Security for web applications has come a long way. In the case of database passwords, there is a lot of approaches to keep them safe: But isn’t it the best if there’s no need for a password at all? With IAM authentication for Cloud SQL, the password can be avoided after all. Here’s how to…

  • Fixed an A2 Error on ASUS Rampage V Extreme

    I have been a bit obsessed with PCs since my parents bought me my first PC, a 386DX with 4MB of memory, almost 30 years ago. Recently one of my friend was selling his crypto mining rig, and I bought the essential parts to start building a new server: I bought a new fan for…

  • How to Self-Host a Mastodon Instance in Kubernetes

    TL;DR: Instead of the official installation including setting up Ruby, nginx, systemd service, etc., I found it more comfortable to install and run a Mastodon instance using some YAML files. Just in case, what is Mastodon anyway? I used kustomize to manage and generate Kubernetes manifests for a fully functional Mastodon instance. Please see my…

  • Cheat Sheet: From SQL to NoSQL

    Recently I was fascinated by MongoDB’s flexibility to change data structure on the fly, in contrast there will need a ALT TABLE SQL statement for any schema change in a SQL database. Here I make a list of typical operations and how they are done in both SQL and NoSQL(in my case, MongoDB) flavours. Create…

  • A Simple RabbitMQ Consumer with Python

    Here’s a very simple RabbitMQ consumer in Python, deployed in a Kubernetes cluster. I used this to act as a consumer for testing purposes. First the Python code: The above code can be saved as a ConfigMap in the cluster: Then the Kubernetes manifest: At last this can be simply deployed with 🙂