Qt6 windows static executables compiled from linux

qt ubuntu

Compiling Qt applications on windows for redistribution is utterly complicated, or impossible (missing dll, crashes, …). So here is a way to compile static qt application, from your preferred unix-like.

Raspberry Pi 4 boot from network

raspberry wifi

Network boot will allow to boot a Raspberry Pi without local storage, and will show it’s full power when using several Raspberry Pi.

Raspberry PI OS headless install

raspberry wifi

Get Raspberry PI OS (I prefer the 64 bit-light).
Flash it (see install guide)
Mount the /boot partition, for instance in /tmp/boot, then run (with the username and password you want) :

ssh configuration

ubuntu ssh

here

Zabbix : store history and trends into influxdb

zabbix grafana influxdb 20.04 18.04 16.04

I’m not particularly fond of influxdb, but since I know it already and since any time-series database should work better than a standard SQL database for time-series, let’s try to store zabbix history into influxdb.

Thunderbird : security.dialog_enable_delay=0

thunderbird 20.04 18.04 16.04

Tired of waiting one second when opening an attachement from Thunderbird?

Understanding and configuring locale

locale ubuntu ssh 20.04 18.04

ubuntu (like most GNU/Linux distributions) is trying hard to speak your language, even in the console, and not only the language, but also the date and number formatting.

Get the Raspberry Pi model from the command line (update #1)

raspberry

Don’t want to open the case of a Raspberry Pi to find it’s model? or are you connected trough ssh? Here is how to identify your Pi from the command line!

somu - FIDO2 security key

ubuntu 18.04 16.04 2fa

2FA using an open source (hardware and firmware) key.

shellcheck - a shell script static analysis tool (update #1)

ubuntu 18.04 16.04 shellcheck bash atom

Considering today’s advent of CI and CD (Continuous Integration and Continuous Development), shell programming is still a thing and is still hard^*1, but shellcheck is a tool that can save you~~r life~~ a lot of time.

df vs du - where my free disk space is gone?

ubuntu 18.04 server

The well kwnown df(disk free) and du(disk usage) are used to display disk usage. But they don’t always tell the same story.

Finding home - dynamic DNS (update #1)

ubuntu 18.04 hw2018 server network openwrt

My ISP would like to charge me $10 a month for a fixed IPv4 address, but accessing your machine remotely only needs a known address, not a fixed one, and that’s why dynamic DNS have been invented.

rsync over ssh to Android

ubuntu 18.04 android rsync ssh

I have tried many ways to sync my music collection to my Android phone, and here is the most comfortable way I could find : the good old rsync.

A webserver to rule them all (update #2)

ubuntu 18.04 hw2018 server apache mysql

Many services I use have a web interface, so here is my basic apache setup. When I say basic, but I mean apache with https, http/2, mysql and phpmyadmin…

atom - yet another editor

ubuntu 18.04 16.04 shellcheck atom

Setup (kindly borrowed from atom’s flight manual)

wget -qO - https://packagecloud.io/AtomEditor/atom/gpgkey | sudo apt-key add -
sudo sh -c 'echo "deb [arch=amd64] https://packagecloud.io/AtomEditor/atom/any/ any main" > /etc/apt/sources.list.d/atom.list'
sudo apt-get update
sudo apt-get -y install atom

grafana speedup (update #1)

ubuntu 18.04 16.04 hw2018 server apache grafana

grafana uses the json data format to transfer data to the browser. While json is easy to work with, it is really bandwidth inefficient. This may not be a problem on a ~~local~~ fast network, but I use grafana through a 10 Mbit/s internet access, so it can be painfully slow.

syncthing headless

ubuntu 18.04 hw2018 server syncthing systemd

syncthing is a FOSS decentralized file sync software, and is even available for most proprietary operating system.

gpg encrypt/decrypt with a passphrase

ubuntu gpg rfc2119

Sometimes you’ve got some files that you don’t want to lose, for instance private keys (think of gpg and Google authenticator), so I store them in multiple places (to be sure that I won’t lose the file) and encrypted since I can’t keep an eye on every place I put my files.

snapper quotas

ubuntu 18.04 hw2018 server btrfs snapper

Today I want to test the status of quotas (displaying size of snapshots) using snapper. This feature is available since snapper 0.6, and the 18.04 only provides 0.5.4.

Canon raw (.cr2) file preview in xfce (update #1)

canon xfce 16.04 18.04

This post is an updated version of that one.

lnav the log file navigator

ubuntu 18.04 server

You may know tail -f, but here is a tool specifically designed to navigate through log files: lnav.

cron tips

ubuntu 18.04 hw2018 server cron

cron can be used to perform ~~boring~~ repetitive tasks and is heavily used by most Linux distributions.

System health monitoring (update #1)

ubuntu 18.04 hw2018 server apache zabbix grafana

This post is an updated version of that one.

Custom service using screen

ubuntu 18.04 hw2018 systemd screen

Here is how to start a systemd service running attached to a console (inside screen).

Canon remote footswitch

canon

Here is how to trigger a Canon camera with a E3 (2.5 mm jack) trigger.

Dropbox headless

ubuntu 18.04 hw2018 server 18.04 dropbox systemd syncthing

This page is about dropbox, but as you may have noticed this page has the flag syncthing, because syncthing is an interesting FOSS alternative.

Offline notification

ubuntu 18.04 16.04 raspberry openwrt server telegram

As we’ve seen in the last post, zabbix is now monitoring our system, and sends alerts as emails but what if the zabbix server crashes or loose internet connectivity? Here comes @PimOnlineBot.

kodi (was xbmc) standalone

ubuntu 16.04 hw2018 kodi tvheadend

Just in case you have:

A computer with an HDMI and USB port
A TV (with HDMI and CEC)
An USB-CEC Adapter
And optionally:
- 40 meters of cat 5e cable
- A HDBaseT transmitter and receiver

It MUST be a RFC about that.

blog

You may have noticed that I sometimes writes some words in UPPERCASE, not because I’m angry, but because there is a RFC about that subject.

Custom services

ubuntu 18.04 hw2018 systemd

The previous post was about services, now let’s evaluate custom services and some other ways to start a program at boot time, without user intervention.

Services

ubuntu 18.04 hw2018 systemd

Services are programs that can be run without user intervention. On ubuntu, they are managed by systemd.

Real life redundancy

blog

Sometimes, failure happens, not only on my server, and not only when I remove the only working drive in my RAID array.

ubuntu 18.04 server btrfs backup

ubuntu 18.04 hw2018 server backup btrfs snapper

While writing the previous posts, I lied. Backup are OK at home, but not on my virtual server that I use for writing this blog.

Installing ubuntu 18.04 server with snapper (update #2)

ubuntu 18.04 btrfs snapper hw2018 server raid-lvm

This post is an updated version of that one.

Growing RAID+LVM+filesystem

ubuntu 18.04 hw2018 server raid-lvm

My / partition is too small, fortunately it is on LVM+RAID, and it’s possible to resize it without downtime!

motd please be quiet!

ubuntu 18.04 hw2018

ubuntu login (`motd`) is too verbose

snapper, the snapshot manager (update #1)

ubuntu 18.04 btrfs hw2018 server snapper

Post updated with simpler rollbacks

Disk health monitoring

ubuntu 18.04 hw2018 server backup

Our system is running well, RAID is running fine, backup are fine, and our server can send email alerts.

Upgrade to openvpn 2.4 on unbutnu 16.04

ubuntu 16.04 openvpn

openvpn default cipher (BF-CBC) is vulnerable to the SWEET32 attack, but since 2.4, openvpn is able to negotiate the cipher with the remote.

Virtual machine made easy

ubuntu 18.04 hw2018 server vm

In this post, I’ll present how I deal with my virtual machines on a server an access them remotely.

ubuntu 18.04 server network bonding

ubuntu 18.04 hw2018 server network

This is the third post in the server series, since backup and snapshots are working, we can now play safely whith the configuration.

Playing with RAID

ubuntu 18.04 hw2018 server raid-lvm

This is the fourth post in the server series. Remember the first post? I installed the server over two RAID arrays, so let’s test if the RAID setup is reliable.

Sending email from the server

ubuntu 18.04 hw2018 sendmail server

A server should be able to send email alerts, just in case some service like cron, mdadm or smartmontools detect a failure.

ubuntu 18.04 server backup with rsync

ubuntu 18.04 hw2018 server backup

This is the second post about running ubuntu 18.04 on my server, if you look at the previous post, the server is ready for use, with snapshot configured and almost nothing more.

randomreaper.blogspot.com is dead

blog

randomreaper.blogspot.com is dead, long live to cli.pignat.org!

Backup

backup

I consider my data important, and since I tend to making fun of guys who lose their data^*1, I take special care of my data. HDD tends to fail, computer can be stolen and cryptoviruses tend to encrypt hard drives, disasters happen.

ubuntu root on LVM over RAID1 degraded boot

ubuntu 16.04 18.04 ximport raid-lvm

`BOOT_DEGRADED` has no effect when using LVM

It seems that using LVM over RAID will always try to boot, no matter how BOOT_DEGRADED is configured. Removing a disk from the running system will put the array in degraded state, and a reboot at this point will work fine, even if this is somehow risky to boot on a degraded array.

Use your outlook calendar from thunderbird+lightning

ximport ubuntu thunderbird lightning outlook

Required software parts

install thunderbird and lightning

  sudo apt-get install xul-ext-lightning

install the latest release of ExchangeCalendar
- Download the .xpi from from here
- In thunderbird : tools > Add-ons > Plugins > settings > Install add-on from file … (select the xpi)
- restart thunderbird

ubuntu 16.04 server serial install

ximport 16.04

Equipment

host computer with a serial port (a USB to serial adapter should do)
target computer with a serial port
Configured for booting over USB
An internet connection
null modem cable
USB flash drive

Find a device on the network, knowing it’s MAC address

ximport ubuntu raspberry network

Here is how to find a device IP address on a DHCP network, knowing only it’s MAC address, an open TCP port and our own IP on the network.

Add a temporary ip address to an existing interface

ximport ubuntu

ip addr add 192.168.1.6/24 dev eth0 label eth0:0

Old school version :

Raspberry pi and SPI LED strip

ximport raspberry apa102

Required material:

buspirate and SPI LED strip

ximport ubuntu apa102

Required material:

perl: warning: Setting locale failed.

ximport ubuntu

You’re connecting through ssh and your remote machine complains about the locale?

adb shell settings put global guest_user_enabled 0

ximport android

EDIT: This one is an untested import, but I like the mood

USB relay (ICSE013A)

ximport ubuntu openwrt

usb relay (ICSE013A) Here is a small and inexpensive Linux friendly USB dual relay: ICStation ICSE013A, available on ebay for less than 5 USD.

Eclipse Mars requires libwebkitgtk

ximport ubuntu eclipse

sudo apt-get install libwebkitgtk-3.0-0

Verifying certificates before deployment

ximport ubuntu ssl openvpn

Every time I setup an VPN using openvpn, I mess something in the certificates or keys. Now I use xca for managing my keys and my life is a little bit easier.