Prototype-X

TL;DR

Install Postgres 9.6, and then:

sudo pg_dropcluster 9.6 main --stop
sudo pg_upgradecluster 9.5 main
sudo pg_dropcluster 9.5 main

Set db path for pg_upgradecluster:

Prototype-X

Install pgAdmin4 v2.0 with python3 on Ubuntu 16.04 DESKTOP mode

1. Get Python Wheel pgAdmin4

    wget https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v2.0/pip/pgadmin4-2.0-py2.py3-none-any.whl
   

2. Install pip3

    sudo apt install python3-pip
   

Prototype-X

#!/bin/bash

while :
do
  echo "$(date) @ $(hostname)"
  echo "Performing new stress testing cycle..."
  stress --cpu 20 --io 20 --vm 6 --vm-bytes 25M --timeout 120s 
  cpu=$(</sys/class/thermal/thermal_zone0/temp)
  echo "-------------------------------------------"
  echo "GPU => $(/opt/vc/bin/vcgencmd measure_temp)"

Prototype-X

#!/bin/bash
# cpustatus
#
# Prints the current state of the CPU like temperature, voltage and speed.
# The temperature is reported in degrees Celsius (C) while
# the CPU speed is calculated in megahertz (MHz).

function convert_to_MHz {
    let value=$1/1000
    echo "$value"

Prototype-X

#!/bin/bash

cpu=$(</sys/class/thermal/thermal_zone0/temp)
echo "GPU => $(/opt/vc/bin/vcgencmd measure_temp)"
echo "CPU => $((cpu/1000))'C"

Prototype-X

README

Timers provided by systemd can be used as cronjob replacements. More at man systemd.timer.

Suppose we want to periodically trigger cleanup tasks for a baz utility. We 'll create a baz-cleanup.service which will be triggered by a baz-cleanup.timer.

Define the target service unit

Create a minimal service at /lib/systemd/system/baz-cleanup.service:

Prototype-X

How to ufw access to tftp-server. Ubuntu 16.04

1. enable conntrack for tftp: modprobe nf_conntrack_tftp
2. check: lsmod|grep tftp
3. add autoload module on boot: echo "nf_conntrack_tftp" >> /etc/modules-load.d/modules.conf
4. ufw allow from 10.0.0.0/8 to any proto udp port 69
5. Profit!!!

http://www.linuxquestions.org/questions/linux-security-4/iptables-with-tftp-conntrack-not-working-4175552639/

Prototype-X

#!/usr/bin/env python

"""
rdns.py

This is a Python script that helps you create
reverse DNS zone files for the Bind Name Server.

I published it together with this blog post: http://goo.gl/CJwly .
"""

Prototype-X

#!/bin/bash
#####################################################
# Name: Bash CheatSheet for Mac OSX
# 
# A little overlook of the Bash basics
#
# Usage:
#
# Author: J. Le Coupanec
# Date: 2014/11/04

Prototype-X

PSQL

Magic words:

psql -U postgres

If run with -E flag, it will describe the underlaying queries of the \ commands (cool for learning!).

Most \d commands support additional param of __schema__.name__ and accept wildcards like *.*