Linux
Installing the Vagrant libvirt Provider on Ubuntu 22.04 LTS
End-to-end setup for running Vagrant on top of KVM/libvirt on Ubuntu 22.04 — virtualization packages, group membership, NFS, plugin build dependencies, and the vagrant-libvirt plugin itself
Installing the Vagrant libvirt Provider on Ubuntu 22.04 LTS
Vagrant ships with VirtualBox as its default provider, but on Linux KVM/libvirt is the better fit: it’s the kernel’s native hypervisor, it’s faster, and it doesn’t require an out-of-tree kernel module. The bridge between the two is vagrant-libvirt, a Vagrant plugin that drives libvirt instead of VirtualBox.
This post walks through the full setup on Ubuntu 22.04 LTS (Desktop or Server). It is largely a distillation of Paul Neumann’s gist, which itself builds on Philippe Vanhaesendonck’s Oracle Linux write-up — kept here for my own reference and slightly reorganized.
SSH Hardening: 9 Techniques That Cut 50,000 Monthly Attacks to Almost Zero
Practical SSH hardening guide with nine production-tested techniques to dramatically reduce brute-force attacks and secure your servers
Last January, I sat down to review a server’s auth logs and felt a familiar knot in my stomach.
Over 50,000 failed SSH login attempts — in a single month. Bots methodically hammering port 22 with common credentials, dictionary wordlists, and leaked password databases. Just waiting for one mistake.
That audit changed how I think about SSH security. Not as a checkbox, but as a discipline. What follows are the nine hardening techniques I’ve since applied across dozens of production servers. Not theoretical guidelines — actual configurations with real, measurable outcomes.
My IP from the Internet's view (shell)
Quick shell one-liners to find your public IP address using curl, dig, and a few alternatives — no browser required
Sometimes you just need to know what IP address the rest of the internet sees when your machine reaches out. Maybe you’re configuring a firewall rule, troubleshooting a VPN, or verifying that traffic is actually leaving through the tunnel you think it is.
No need to open a browser. A terminal is enough.
Convert openssh keys to rsa keys
Convert openssh keys to rsa keys
Convert openssh keys to rsa keys
from something that starts with
-----BEGIN OPENSSH PRIVATE KEY-----
to something that starts with
-----BEGIN RSA PRIVATE KEY-----
A set of ansible role to configure a Linux account
I’ve just make a public repository where I have written some roles to install/configure a Linux desktop account. The prerequisite is ansible and to have an access to the root account for some setup.