Don Figuerres

Setting up multiple SSH keys in a single machine

Mon, 05 May 2025 22:00:00 +0800

This is helpful in order to authenticate using SSH keys in a single machine for multiple accounts.

For example, you want to setup SSH keys in GitHub to authenticate for you work account and another SSH key to authenticate for your personal account.

Step 1: Generate SSH keys

ssh-keygen -t ed25519 -C "<your_email@example.com> <your organization name> <service>"

# Example
ssh-keygen -t ed25519 -C "myaccount@gmail.com MyOrg GitHub"

When asked for the file path of the key, make sure to add more context to the file name. I usually use encryption_service_org.

Tmux Settings

Tue, 28 May 2024 22:40:00 +0800

Saving here a copy of tmux settings so it’s easy to set it up in a new machine.

set -g mouse on
# vi keybindings
set-window-option -g mode-keys vi
bind-key -T copy-mode-vi v send -X begin-selection
bind-key -T copy-mode-vi V send -X select-line
bind-key -T copy-mode-vi y send -X copy-pipe-and-cancel 'xclip -in -selection clipboard'
# required by neovim checkhealth
set -g default-terminal "tmux-256color"
set-option -sa terminal-features ',xterm-256color:RGB'
set-option -sg escape-time 10
set-option -g focus-events on

Dark Theme in WSL2 GUI

Tue, 09 Aug 2022 10:49:00 +0800

Running GUI apps in WSL2 has finally been made easier in more recent versions of Windows 11 and Windows 10 with WSL2. If you’re like me, who use Windows as a daily driver for software development, you know that this makes life a bit easier.

Before the recent updates, you had to install an X Server and that is what you set as your display in your WSL2 environment - a bit old school. But now, WSL2 is better integrated with the host Windows environment that you no longer need to install an X Server for Linux GUI apps to work.

Hosting a Website Using AWS S3

Thu, 04 Aug 2022 10:23:00 +0800

NOTE: This post is still a work in progress.

This blog talks about how to setup a website using AWS S3 which might be intimidating for complete beginners. I also plan to create a tutorial/blog for complete beginners who want to setup their own website which I should link here in the future.

Overview

Hosting a website typically requires you to setup the following.

Web Server - where all your files uploaded and served through the network
Content Delivery Network (CDN) - where your static files are cached
Certificate - for SSL
Domain Name System (DNS) - where your domain name is registered

Component	What we’ll use
Web Server	S3
CDN	CloudFront
Certificate	ACM
DNS	GoDaddy

Step 1: Setup your S3 bucket

Create an S3 bucket in your AWS account and enable Static website hosting. Uncheck Block all public access and add a bucket policy. These settings will allow your files to be publicly accessed.

VS Code Python Test Debugging Does Not Hit Breakpoint

Tue, 26 Jul 2022 00:00:00 +0800

I had this problem in Python development environment wherein a breakpoint is not hit while trying to debug tests. It turns out that this is a known issue and a work around is available via the launch.json file.

{
 "version": "0.2.0",
 "configurations": [
 {
 "name": "Debug Tests",
 "type": "python",
 "request": "launch",
 "purpose": [
 "debug-test"
 ],
 "console": "integratedTerminal",
 "justMyCode": false,
 "env": {
 "PYTEST_ADDOPTS": "--no-cov"
 }
 }
 ]
}

Below is the explanation form Microsoft.

Global gitignore File

Fri, 01 Jul 2022 23:15:00 +0800

When working with a version control system, you normally have files that are not ignored in some projects but you would like to ignore in globally in your workstation environment. The ways to do that are listed below.

Option 1: The git/ignore file in the home directory

The user’s ignore file is mentioned briefly in the Git documentation. You can add here your ignore rules the same way as you do it with your project .gitignore rules.

How to swap the Fn and Ctrl keys in a Lenovo laptop

Fri, 01 Jul 2022 18:52:00 +0800

I’ve been issued a lenovo laptop for the first time and the first thing I noticed is this weird keyboard layout where the typical locations of the left Fn and Ctrl keys are interchanged. I’m already used to the typical layout where the Ctrl key is in the leftmost part followed by the Fn key. Fortunately, Lenovo has made it possible to swap the Fn and Ctrl keys through BIOS. The complete instructions are in this how-to article.

Common Tools for Software Development

Thu, 23 Jun 2022 23:34:00 +0800

List of tools that I’ve used throughout my development career that you might find useful too. I use this list when setting up a new VM or workstation.

Browser

Google Chrome
- It’s most people’s default browser although Edge has a better performance in Windows.
Brave Browser
- I use this personally for browsing.
- It has a lot of default privacy features.
- Can be used to test if a website will continue to function if all the security and privacy features are enabled.
Firfox
- Has cool privacy features and containerization feature.

Package Manager

Homebrew
- Homebrew initially started as a MacOS package manager but is now available for Linux distros. It’s a good package manager if you want to always have the latest version of the software you need. Otherwise, it’s hard to keep older versions as the philosophy of Homebrew is to only maintain the latest versions.

Editor

VSCode

Java Performance Testing Using Zerocode

Wed, 22 Jun 2022 23:10:00 +0800

In one of my previous projects, I had to add a performance testing suite for our Java APIs to measure the performance gain in the performance improvement that I was working on.

After some research, I found that Zerocode is able to fulfill our needs. Their GitHub Repo also includes an extensive documentation which made the process much easier for me.

I found that you can reuse your existing JUnit tests as performance tests using the LoadWith annotation.

Git Connection Errors During Cloning

Fri, 14 Jan 2022 17:18:36 +0800

I got these errors recently when I was trying to clone one of our repos. Unstable network connection or network infrastructure may have caused this so as a workaround, you can clone the repo “bit-by-bit”.

$ git clone ssh://git@your.host.com/yourrepo.git
Cloning into 'projectdir'...
 ...
remote: Enumerating objects: 26639, done.
remote: Counting objects: 100% (269/269), done.
remote: Compressing objects: 100% (152/152), done.
client_loop: send disconnect: Connection reset by peer6 MiB/s
fetch-pack: unexpected disconnect while reading sideband packet
fatal: fetch-pack: invalid index-pack output

$ git clone ssh://git@your.host.com/yourrepo.git
Cloning into 'projectdir'...
 ...
remote: Enumerating objects: 26639, done.
remote: Counting objects: 100% (269/269), done.
remote: Compressing objects: 100% (152/152), done.
client_loop: send disconnect: Connection reset by peer9 MiB/s
fatal: early EOF
fatal: fetch-pack: invalid index-pack outputing sideband packet

Workaround

The workaround is to checkout the repo bit-by-bit.

Changing Committer, Author, and Email in Git

Tue, 10 Aug 2021 00:12:25 +0800

I recently observed in my GitHub profile that most of my commits are not shown in my contribution activity. After doing a quick search, I found that the problem because my email in my commits do not match the email associated with my GitHub account.

Changing Commits in the Remote Repository

You need to use the filter-branch command to change the emails and names.

git filter-branch -f --env-filter '
 GIT_AUTHOR_NAME="yourname";
 GIT_AUTHOR_EMAIL="youremaill@host.com"
 GIT_COMMITTER_NAME="yourname";
 GIT_COMMITTER_EMAIL="youremail@host.com"
' HEAD

The command above changes the email and name for all of the commits. If you’re working on a shared repository, you need to use an if statement to change only your commits.

Factorial

Tue, 01 Jun 2021 02:57:52 +0800

Factorial is the product of all positive integers less than or equal to a given positive integer and denoted by that integer and an exclamation point.

n! = n * (n-1) * (n-2) * (n-3) ... 3 * 2 * 1

For example

5! = 5 * 4 * 3 * 2 * 1 = 120

Just like the Fibonacci sequence, this is one of the basic forms of exercise used in programming and is commonly used to introduce recursion. I have written here both iterative and recursive implementations.

Fibonacci Sequence

Tue, 01 Jun 2021 00:12:25 +0800

The Fibonacci sequence is a series of numbers where a number is the addition of the last two numbers. This is one of the basic forms of exercise used in programming and is almost always present in a programming exam. Therefore, learning how to print the Fibonacci sequence is essential to anyone learning programming or a new programming language.

0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

CentOS 7 VirtualBox 5.2 Error

Wed, 25 Oct 2017 00:00:00 +0000

Issue

A recent linux kernel update (3.10.0-693.2.2.el7.x86_64) caused the VirtualBox Guest Additions 5.2 in my CentOS7 box to break.

Error message:

/tmp/vbox.0/hgsmi_base.c: In function ‘hgsmi_send_caps_info’:
/tmp/vbox.0/hgsmi_base.c:99:2: error: implicit declaration of function ‘AssertRC’ [-Werror=implicit-function-declaration]
 AssertRC(p->rc);^M
 ^
cc1: some warnings being treated as errors
make[2]: *** [/tmp/vbox.0/hgsmi_base.o] Error 1
make[1]: *** [_module_/tmp/vbox.0] Error 2
make: *** [vboxvideo] Error 2

More information is in this virtualbox thread

virtualbox ticket

Resolution

An updated VirtualBox Guest Additions installer which contains the fix can now be downloaded from the virtualbox website.