Til

TIL 2020-08-02 EC2 Free Tier - EC2 has a Free tier! You can request a bunch of machines to experiment with cloud infrastructure. Juju Configuration Management - Juju is a tool that helps manage server providers, whether they are GCP, AWS, your own servers or Azure, among others, giving you one unified way to start, setup and run your servers. Juju Charms - Juju’s configurations are called charms, and these are written in Python. ...

Linux System Administration Linux Kernel 5.8 Features Linux Kernel 5.8 has a lot of hardware level optimizations Significant improvements in hardware support and performance Better power management and efficiency Enhanced driver support for newer hardware Performance improvements across various subsystems Multi-Kernel Installation and Management You can install more than one kernel into a Linux installation and choose which to boot from in Grub Enables testing newer kernels while keeping stable fallback options Useful for development, testing, and troubleshooting Grub bootloader provides menu for kernel selection at boot time Benefits of Multi-Kernel Setup System Stability Ability to rollback to previous kernel if new version causes issues Critical for production systems and development environments Reduces risk when updating system components Development and Testing Test new kernel features without losing stable system Compare performance between kernel versions Debug kernel-specific issues by switching between versions Recovery Options Broken kernel update doesn’t render system unbootable Always have working kernel available for system recovery Essential for maintaining system uptime and reliability

TIL 2020-08-01 Python collections.defaultdict - Takes a type not a value. It will initialize based on the default value for that type. Git Last Commit ID - git log --format="%H" -n 1 | cat outputs the last commit ID. Node.js Command Line Arguments - Node.js uses the process object to access command line arguments.

Python Programming Collections Module - defaultdict collections.defaultdict takes a type not a value It will initialize based on the default value for that type Common mistake: passing a value instead of a callable type Example: defaultdict(list) not defaultdict([]) Cleaner than manually checking if keys exist before accessing Version Control Git Commands and Tricks git log --format="%H" -n 1 | cat outputs the last commit ID Useful for scripting and automation The cat ensures the output is properly formatted %H format specifier gives the full commit hash -n 1 limits to the most recent commit Cloud Infrastructure and DevOps AWS EC2 Free Tier EC2 has a Free tier! I can request a bunch of machines here Great for learning and experimenting with cloud infrastructure Limited resources but sufficient for development and testing Good entry point for understanding cloud computing concepts Juju - Multi-Cloud Orchestration Juju is a tool that helps manage server providers, whether they are GCP, AWS, your own servers or Azure, among others Gives you one way to start, setup and run your servers across different cloud providers Abstracts away cloud provider differences Enables consistent deployment across hybrid and multi-cloud environments Juju Configuration System Juju’s configurations are called charms These are written in Python Charms define how services should be deployed and configured Reusable deployment patterns for common software stacks Community-maintained charm store with pre-built configurations

Today I learned about Docker graph drivers and container networking, Julia Evans' excellent systems programming explanations, and comprehensive Kubernetes architecture through Kamal Marhubi's ground-up approach.

Today I learned about Linux productivity enhancements including volume control in xmonad, mouse gestures with Fusuma, and fundamental Rust ownership principles.

Today I learned about Advent of Code programming challenges, GPU hash tables, Python gotchas, Rust concurrent data structures, and various development tools and learning resources.

Today I learned about Python collections.defaultdict performance benefits, the sorted function's reverse parameter, and using arandr as a frontend for xrandr in tiling window managers.

Today I learned about testing Dash applications with pytest and selenium, implementing Flask-Dash integration patterns, and understanding Pi-hole's FTL engine based on dnsmasq.

TIL 2020-07-23 Memoizing Dash Callback Responses with Flask-Caching - It’s possible to cache dash callback responses for better performance using flask-caching. Configurable Dash Registration - Always ensure that dash registration in a Flask-Dash app is configurable. You might want to skip loading dash when testing backend-only functionality. pytest-dash Status - pytest-dash has been abandoned since the official dash repository now supports Selenium testing via pytest directly.