Create readonly user in Postgres

CREATE USER testuser WITH PASSWORD 'somepassword';
GRANT CONNECT ON DATABASE dbtest TO testuser;

//remove all permission, only superuser can perform db actions
REVOKE ALL ON schema public FROM public;
//remove all table permission from user
REVOKE ALL ON ALL TABLES IN SCHEMA public FROM testuser;
//grant select permission to user
GRANT SELECT ON ALL TABLES IN SCHEMA public TO testuser;

Upgrade Debian Kernel

Replace buster with suitable version

echo "deb http://ftp.debian.org/debian buster-backports main" | sudo tee -a /etc/apt/sources.list > /dev/null

sudo apt-get -t buster-backports upgrade

apt search Linux-image

result look like (with first phrase split by slash is image name which can install-able)

linux-headers-4.19.0-6-amd64/stable 4.19.67-2+deb10u2 amd64
  Header files for Linux 4.19.0-6-amd64

linux-headers-4.19.0-6-cloud-amd64/stable 4.19.67-2+deb10u2 amd64
  Header files for Linux 4.19.0-6-cloud-amd64

linux-headers-4.19.0-6-rt-amd64/stable 4.19.67-2+deb10u2 amd64
  Header files for Linux 4.19.0-6-rt-amd64

linux-headers-4.19.0-8-amd64/stable,stable 4.19.98-1 amd64
  Header files for Linux 4.19.0-8-amd64

linux-headers-4.19.0-8-cloud-amd64/stable,stable 4.19.98-1 amd64
  Header files for Linux 4.19.0-8-cloud-amd64

linux-headers-4.19.0-8-rt-amd64/stable,stable 4.19.98-1 amd64
  Header files for Linux 4.19.0-8-rt-amd64

linux-headers-5.4.0-0.bpo.2-amd64/buster-backports 5.4.8-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.2-amd64

linux-headers-5.4.0-0.bpo.2-cloud-amd64/buster-backports 5.4.8-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.2-cloud-amd64

linux-headers-5.4.0-0.bpo.2-rt-amd64/buster-backports 5.4.8-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.2-rt-amd64

linux-headers-5.4.0-0.bpo.3-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.3-amd64

linux-headers-5.4.0-0.bpo.3-cloud-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.3-cloud-amd64

linux-headers-5.4.0-0.bpo.3-rt-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.3-rt-amd64

linux-headers-5.4.0-0.bpo.4-amd64/buster-backports 5.4.19-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.4-amd64

linux-headers-5.4.0-0.bpo.4-cloud-amd64/buster-backports 5.4.19-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.4-cloud-amd64

linux-headers-5.4.0-0.bpo.4-rt-amd64/buster-backports 5.4.19-1~bpo10+1 amd64
  Header files for Linux 5.4.0-0.bpo.4-rt-amd64

linux-image-4.19.0-6-amd64/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for 64-bit PCs (signed)

linux-image-4.19.0-6-amd64-dbg/stable 4.19.67-2+deb10u2 amd64
  Debug symbols for linux-image-4.19.0-6-amd64

linux-image-4.19.0-6-amd64-unsigned/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for 64-bit PCs

linux-image-4.19.0-6-cloud-amd64/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for x86-64 cloud (signed)

linux-image-4.19.0-6-cloud-amd64-dbg/stable 4.19.67-2+deb10u2 amd64
  Debug symbols for linux-image-4.19.0-6-cloud-amd64

linux-image-4.19.0-6-cloud-amd64-unsigned/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for x86-64 cloud

linux-image-4.19.0-6-rt-amd64/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for 64-bit PCs, PREEMPT_RT (signed)

linux-image-4.19.0-6-rt-amd64-dbg/stable 4.19.67-2+deb10u2 amd64
  Debug symbols for linux-image-4.19.0-6-rt-amd64

linux-image-4.19.0-6-rt-amd64-unsigned/stable 4.19.67-2+deb10u2 amd64
  Linux 4.19 for 64-bit PCs, PREEMPT_RT

linux-image-4.19.0-8-amd64/stable,stable,now 4.19.98-1 amd64 [installed]
  Linux 4.19 for 64-bit PCs (signed)

linux-image-4.19.0-8-amd64-dbg/stable,stable 4.19.98-1 amd64
  Debug symbols for linux-image-4.19.0-8-amd64

linux-image-4.19.0-8-amd64-unsigned/stable,stable 4.19.98-1 amd64
  Linux 4.19 for 64-bit PCs

linux-image-4.19.0-8-cloud-amd64/stable,stable 4.19.98-1 amd64
  Linux 4.19 for x86-64 cloud (signed)

linux-image-4.19.0-8-cloud-amd64-dbg/stable,stable 4.19.98-1 amd64
  Debug symbols for linux-image-4.19.0-8-cloud-amd64

linux-image-4.19.0-8-cloud-amd64-unsigned/stable,stable 4.19.98-1 amd64
  Linux 4.19 for x86-64 cloud

linux-image-4.19.0-8-rt-amd64/stable,stable 4.19.98-1 amd64
  Linux 4.19 for 64-bit PCs, PREEMPT_RT (signed)

linux-image-4.19.0-8-rt-amd64-dbg/stable,stable 4.19.98-1 amd64
  Debug symbols for linux-image-4.19.0-8-rt-amd64

linux-image-4.19.0-8-rt-amd64-unsigned/stable,stable 4.19.98-1 amd64
  Linux 4.19 for 64-bit PCs, PREEMPT_RT

linux-image-5.4.0-0.bpo.2-amd64/buster-backports,now 5.4.8-1~bpo10+1 amd64 [installed]
  Linux 5.4 for 64-bit PCs (signed)

linux-image-5.4.0-0.bpo.2-amd64-dbg/buster-backports 5.4.8-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.2-amd64

linux-image-5.4.0-0.bpo.2-amd64-unsigned/buster-backports 5.4.8-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs

linux-image-5.4.0-0.bpo.2-cloud-amd64/buster-backports 5.4.8-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud (signed)

linux-image-5.4.0-0.bpo.2-cloud-amd64-dbg/buster-backports 5.4.8-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.2-cloud-amd64

linux-image-5.4.0-0.bpo.2-cloud-amd64-unsigned/buster-backports 5.4.8-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud

linux-image-5.4.0-0.bpo.2-rt-amd64/buster-backports 5.4.8-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT (signed)

linux-image-5.4.0-0.bpo.2-rt-amd64-dbg/buster-backports 5.4.8-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.2-rt-amd64

linux-image-5.4.0-0.bpo.2-rt-amd64-unsigned/buster-backports 5.4.8-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT

linux-image-5.4.0-0.bpo.3-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs (signed)

linux-image-5.4.0-0.bpo.3-amd64-dbg/buster-backports 5.4.13-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.3-amd64

linux-image-5.4.0-0.bpo.3-amd64-unsigned/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs

linux-image-5.4.0-0.bpo.3-cloud-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud (signed)

linux-image-5.4.0-0.bpo.3-cloud-amd64-dbg/buster-backports 5.4.13-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.3-cloud-amd64

linux-image-5.4.0-0.bpo.3-cloud-amd64-unsigned/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud

linux-image-5.4.0-0.bpo.3-rt-amd64/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT (signed)

linux-image-5.4.0-0.bpo.3-rt-amd64-dbg/buster-backports 5.4.13-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.3-rt-amd64

linux-image-5.4.0-0.bpo.3-rt-amd64-unsigned/buster-backports 5.4.13-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT

linux-image-5.4.0-0.bpo.4-amd64/buster-backports,now 5.4.19-1~bpo10+1 amd64 [installed]
  Linux 5.4 for 64-bit PCs (signed)

linux-image-5.4.0-0.bpo.4-amd64-dbg/buster-backports 5.4.19-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.4-amd64

linux-image-5.4.0-0.bpo.4-amd64-unsigned/buster-backports 5.4.19-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs

linux-image-5.4.0-0.bpo.4-cloud-amd64/buster-backports 5.4.19-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud (signed)

linux-image-5.4.0-0.bpo.4-cloud-amd64-dbg/buster-backports 5.4.19-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.4-cloud-amd64

linux-image-5.4.0-0.bpo.4-cloud-amd64-unsigned/buster-backports 5.4.19-1~bpo10+1 amd64
  Linux 5.4 for x86-64 cloud

linux-image-5.4.0-0.bpo.4-rt-amd64/buster-backports 5.4.19-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT (signed)

linux-image-5.4.0-0.bpo.4-rt-amd64-dbg/buster-backports 5.4.19-1~bpo10+1 amd64
  Debug symbols for linux-image-5.4.0-0.bpo.4-rt-amd64

linux-image-5.4.0-0.bpo.4-rt-amd64-unsigned/buster-backports 5.4.19-1~bpo10+1 amd64
  Linux 5.4 for 64-bit PCs, PREEMPT_RT

linux-image-amd64/stable,stable,now 4.19+105+deb10u3 amd64 [installed]
  Linux for 64-bit PCs (meta-package)

linux-image-amd64-dbg/stable,stable 4.19+105+deb10u3 amd64
  Debugging symbols for Linux amd64 configuration (meta-package)

linux-image-amd64-signed-template/stable,stable 4.19.98-1 amd64
  Template for signed linux-image packages for amd64

linux-image-cloud-amd64/stable,stable 4.19+105+deb10u3 amd64
  Linux for x86-64 cloud (meta-package)

linux-image-cloud-amd64-dbg/stable,stable 4.19+105+deb10u3 amd64
  Debugging symbols for Linux cloud-amd64 configuration (meta-package)

linux-image-rt-amd64/stable,stable 4.19+105+deb10u3 amd64
  Linux for 64-bit PCs (meta-package), PREEMPT_RT

linux-image-rt-amd64-dbg/stable,stable 4.19+105+deb10u3 amd64
  Debugging symbols for Linux rt-amd64 configuration (meta-package)

Choose image which you want to install,

sudo apt-get -t buster-backports install linux-image-5.4.0-0.bpo.4-amd64

uname -r

Make Viber larger font

I modified the Exec= line in /usr/share/applications/viber.desktop to this:

Exec=/usr/bin/env QT_AUTO_SCREEN_SCALE_FACTOR=1 QT_SCALE_FACTOR=1.5 /usr/bin/viber

Move Desktop Launcher to shared apps

1. Create Desktop launcher
sudo apt  install --no-install-recommends gnome-panel
gnome-desktop-item-edit ~/Desktop/ --create-new

2. Move to shared apps
sudo mv YourApp.desktop /usr/share/applications

update firmware intel

https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/i915

check CPU code (skylake, kabylake ...) and download latest files for each categories.

cd /lib/firmware/i915/

put downloaed files into this.

Reduce laptop overheat

Install TLP and thermald

sudo add-apt-repository ppa:linrunner/tlp
sudo apt-get update sudo apt-get install tlp tlp-rdw
sudo apt-get install thermald



https://itsfoss.com/reduce-overheating-laptops-linux/

Bug cannot detect UTF-8 when ssh deploy (Mac OS)

nano /etc/ssh/ssh_config

comment the line
SendEnv LANG LC_*