Andre Skarzynski m0jek

How to configure postfix mail for iCloud & GMail

Perfect to configure alertnotify in bitcoin.conf for bitcoind
i.e. alertnotify=echo %s | mail -a "From: Sender <[email protected]>" -s "Bitcoin Alert" [email protected]

On Linux, Raspberry Pi, Debian, Ubuntu install:

$ sudo apt-get install postfix mailutils libsasl2-modules

Citrix Workspace

In this manual I assume that we'll be using usb audio handset instead of hdmi audio output

Step

Check available architectures first

$ dpkg --print-architecture

Think twice before abandoning X11. Wayland breaks everything!

Wayland breaks everything! It is binary incompatible, provides no clear transition path with 1:1 replacements for everything in X11, and is even philosophically incompatible with X11. Hence, if you are interested in existing applications to "just work" without the need for adjustments, then you may be better off avoiding Wayland.

Wayland solves no issues I have but breaks almost everything I need. Even the most basic, most simple things (like xkill) - in this case with no obvious replacement. And usually it stays broken, because the Wayland folks mostly seem to care about Automotive, Gnome, maybe KDE - and alienating everyone else (e.g., people using just an X11 window manager or something like GNUstep) in the process.

Feature comparison

Tutorial: MQTT and the retain flag

Assumptions and setup

This tutorial assumes:

a single computer (like a Raspberry Pi)
MQTT broker (like Mosquitto) running
the mosquitto_pub and mosquitto_sub commands are available.

Ubuntu 20.04 on a 15" Retina MacBook Pro (Mid-2014)

These are notes from my efforts to get Ubuntu 20.04 installed on my older MacBook Pro. I'm making this gist public in the hopes that it's helpful to others.

I did a Minimal install, but selected the option to install additional 3rd-party drivers.

Wifi doesn't work during the install (because it requires a 3rd-party driver), so you won't be able to choose to download updates while installing. No big deal, run a software update after the install.

The installer takes about 25 minutes to complete. Post-install, most things work. The only driver I had to manually install was for the FaceTime camera. More on that below.

Recipe: from MQTT to InfluxDB via Node-RED

2024-05-16 adds case study explaining how to extract values from topic strings, and how to specify the measurement name in the message payload provided to the "influxdb out" node.
2023-12-02 revise graphics to correspond with "influxdb out" node, and explain the pros and cons of InfluxDB 1.8 vs InfluxDB 2.

Introduction

Getting data produced by IoT sensors into a database is practically a mandatory step before effective visualisation (eg dashboards).

This recipe shows you how to get an MQTT payload into an InfluxDB database using three Node-RED nodes. It makes the following assumptions:

Journalctl Cheat Sheet

Configuration

Permissions

To see messages from other users and the system as well as performing various log operations from a regular user add it to the group:

sudo usermod -aG systemd-journal $USER

	__NOTOC__
	Notes on the Sinclair ZX Spectrum Next [[Retro Gaming]], [[ZX Spectrum]], [[Z80 Assembly Language]]

	==Next BASIC==
	===Editor===
	EXTEND MODE, CAPSLOCK - Start of program<br/>
	EXTEND MODE, GRAPHICS - End of program
	<pre>
	ERASE 100,200 ;Erase lines 100 to 200
	LINE 100,2 ;Renumbers lines from 100 in steps of 2, 100, 102, 104, 106...

	#!/usr/bin/python3
	#
	# load_agps_data
	#
	# proof of concept loading of agps data to quectel modem via AT commands

	from datetime import datetime, timezone
	import requests
	import serial

	########################
	# To modify openldap ACL
	########################

	# delete the existing ACL

	# delete-acl.ldif
	dn: olcDatabase={1}hdb,cn=config
	changetype: modify
	delete: olcAccess