Adding New Key per User to AWS EC2 Instance

When we create a new server in aws, it allows us to generate a key pair and attach it to the server. Now imagine you want to share access to this multiple people in your team, but you don’t want to share your private key. This is what you need to do.

  • Generate new key for each member of your team or ask each member for there public keys
  • Add it to the authorized_keys list in your servers .ssh folder

HTOP for GPU in Linux

htop/top is a useful command that helps users understand how much of there CPU (Different core)/RAM are being used. We would like to see the same for GPU there are tools that provide that, but sadly unlike cpu top/htop the ones for GPU are sadly fragmented. Based on your GPU vendor we have different tools to provide us this graphical info. Note: I am talking about tools i tested in Ubuntu/Debian Linux

How I Setup Dark Theme in My Blog

Dark mode or night mode is becoming more and more popular these days. As the amount of time we are spending in front of the computer increases, we started to look more into on how to improve our experience. Dark mode/Night mode is one such setting. What it does (mainly) is it makes all the white part of the application to black - major chunk of which would be the background. When the color of the background is made black, it emits less light. Now not all displays are the same, each display creates the dark color in different ways. Like:

  • On an LCD screen. The liquid crystal elements block the white light from the backlight. And this results in a dark (almost black) pixel.
  • On an OLED screen. The pixel is turned off, no light is emitted, this produces a deep black.
  • On a CRT screen. The electron beam is turned off as it passes the pixel. Producing no phosphorescent glow.
  • On an e-Ink screen. Little spherical beads which are half black/half white, are rotated so their black side is facing outwards.

Regardless as you can see, darker colors results in less lights being emitted and leading to less strain to the eye. As a person who spend more time in front of a screen, I cannot fathom how useful this is. I have been a huge advocate of using night color/night mode in computer to improve developer health. Hence this article and why my blog has a dark mode now.

Using String in Active Record(Rails) Enum

Rails model helps you define enum on a database integer field quite easily. The enum method which rails provide in its model is not an interface to the enum datatype available in some databases, but converting or using a integer field as an enum. Enum type or Enumerated type is user defined data type where you define the set of value the data type will have. If you consider regular or basic or primitive data types, they are pretty much like enum where the values it can hold is defined already by the language. Ruby dynamic type system does hide all this complexity for us while we develop.

Enum is quite useful when you want to make sure that only a specified list of values are saved for a field.