shamil

How to mount a qcow2 disk image

This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.

Step 1 - Enable NBD on the Host

modprobe nbd max_part=8

shamil

Use folowing steps to repackage dep package:

1: Extract deb package
    # dpkg-deb -x <package.deb> <dir>

2: Extract control-information from a package
    # dpkg-deb -e <package.deb> <dir/DEBIAN>

3. After completed to make changes to the package, repack the deb
    # dpkg-deb -b <dir> <new-package.deb>

shamil

#!/bin/bash -e
# see related issue: https://github.com/rundeck/rundeck/issues/357 

# export required vars
export RD_URL=http://localhost:4440 RD_USER=admin RD_PASSWORD=admin RD_HTTP_TIMEOUT=300

# make sure rd & jq commands are in the PATH
which -- rd jq >/dev/null

del_executions() {

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receivers:
- name: default
  slack_configs:
  - api_url: https://hooks.slack.com/services/...
    channel: alerts
    send_resolved: true
    title: '' # important, put empty string here
    text: '{{ template "slack.shamil.text" . }}'

shamil

# how to redirect from one port to another using iptables
###

# install following package in order to preserve the iptables rules
sudo apt-get install iptables-persistent

# redirect from port 80 to port 8000
sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8000

# redirect from one IP to other

shamil

Client-side SSL

Create a Certificate Authority root (which represents this server)

Organization & Common Name: Some human identifier for this server CA.

openssl genrsa -out ca.key 2048
openssl req -new -x509 -days 365 -key ca.key -out ca.crt

Create the Client Key and CSR

shamil

Source

TFTP server on Fedora

Here are some quick notes on setting up a TFTP server on Fedora 23. This is used, for example, to send Linux kernel images and other binaries to a bootloader on an embedded system.

First, install the packages:

sudo dnf install -y tftp tftp-server

shamil

function uuid() {
  var uuid = "", i, random;
  for (i = 0; i < 32; i++) {
    random = Math.random() * 16 | 0;

    if (i == 8 || i == 12 || i == 16 || i == 20) {
      uuid += "-"
    }
    uuid += (i == 12 ? 4 : (i == 16 ? (random & 3 | 8) : random)).toString(16);
  }

shamil

Enable PipeWire on Ubuntu 22.04

This guide is only for original Ubuntu out-of-the-box packages. If you have added a custom PPA like pipewire-debian, you might get into conflicts.

Ubuntu 22.04 has PipeWire partially installed and enabled as it's used by browsers (WebRTC) for recoding the screeen under Wayland. We can enable remaining parts and use PipeWire for audio and Bluetooth instead of PulseAudio.

Starting from WirePlumber version 0.4.8 automatic Bluetooth profile switching (e.g. switching from A2DP to HSP/HFP when an application needs microphone access) is supported. Jammy (22.04) repos provide exactly version 0.4.8. So, we're good.

Based on Debian Wiki, but simplified for Ubuntu 22.04.

shamil

PostgreSQL 9.x Sequence Fixing Script

This script is intended to automatically fix the sequence numbers for all tables in the current database.

This is accomplished through the use of the setval() command, which we provide with the next ID value we wish to make use of. We use the setval(sequence, number, is_called) overload and set is_called = false in conjunction with COALESCE(MAX + 1, 1) to ensure that, with an empty table, the next sequence value is 1 as expected.

Running