Linux

Finding out which Linux Version running

cat /etc/issues
cat /etc/os-release  
hostnamectl
cat /etc/upstream-release/lsb-release

/etc/issues: Linux Mint 21.1 Vera \n \l
/etc/os-release: more mint details
/etc/upstream-release/lsb-release: Ubuntu info
lsb-release: Here I will collect my general Tips on Linux`

Directories and permissions

place additional package managers and executables in and config files.

~/.local/
~/.config/

Pretty Printing Path with each entry in new line as alias ep

alias ep='echo $PATH | tr ":" "\n"'

Generate Random strings

thanks to How-to-Geek Generating 20 character long random strings.

openssl rand -base64 20

< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c20

On Mac prepend it with LC_CTYPE=C, like

< /dev/urandom | LC_CTYPE=C tr -dc _A-Z-a-z-0-9 | head -c24

Setup ssh Key connectivity

Install openssh_server

sudo apt install openssh-server
sudo systemctl is-enabled ssh

Generate a new ssh key pair

ssh-keygen -t rsa -b 2048 -C "comments etc" -f ~/.ssh/outfile -N ""
ssh-add ~/outfile

preferably store it in /home/<user>/.ssh/<keyname> and append it into the authorized_keys File. Use the -N "" to avoid being prompted for a passphrase if desired.

cat ~/.ssh/<keyname>.pub >> ~/.ssh/authorized_keys

Update the sshd configuration to allow key based authorization. My preffered configuration checks the users .ssh directory for and authorized_keys File and also checks for a file per user like /etc/ssh/authorized_keys/<user> Depending on the Firewall settings I sometimes have to run the openssh-server on a different port than 22

Port <port_of_choice>
PubkeyAuthentication yes
PasswordAuthentication no
AuthorizedKeysFile %h/.ssh/authorized_keys /etc/ssh/authorized_keys/%u

Lastly copy the private keyname file to the machine you want to use to connect from. The private keyfile is the key to access your host use caution and encryption when to save or share it.

scp ~/.ssh/keyname user@host:~/.ssh/

Setting up Debian

I used the debian-9.8.0-amd64-netinst.iso image. First I highlighted the Install option to avoid using the graphical installer. This is because I had issues in an earlier install when I was monitoring the log output and then switching back to the first console. Then I hit tab to add and additional boot parameter netcfg/disable_autoconfig=true. This was because when I used automated Network Configuration, it defaulted to IPv6 and then froze when it tried to copy the apt mirrors because it didn't fell back to IPv4. I also used the following Partioning Table setup.

To see the log output press Ctrl+Alt+4 to switch back press 1 instead or use 2or3 to start a console terminal See also Debian-Installer 5.1.7. The Boot Screen Debian-Installer 5.3.2. Debian Installer Parameters Debian-Installer 6.1. How the Installer Works

LVM

LVM stands for Logical Volume Management and is used to create, display and manage Physical Volumes(pv), Volume Groups (vg), and Logical Volumes (lv)

Installing Xen

As described in Xen Getting started

apt-get install xen-system-amd64 lvm2
pvcreate /dev/sda7
vgcreate vg0 /dev/sda7

/dev/sda7 differs from the turorial due to my different partion tables I re-installed Linux-Mint on a setup with existing LVM settings. I mounted a data volume in /etc/fstab with lvdisplay revealed the $ LV Path as /dev/vg-01/data01

/dev/vg-01/data01       /data   ext4    defaults        0       0

NFS Issues

Make sure the /etc/exports file on the nfs server has the right ip addresses. They did not get updated when the ip address of the server changed due to a change of my ISP. The shared folder on the NasDrive needs to have nfs Permissions:

Setting

Value

- Client:

10.0.0.*

+ Privilege:

Read/Write

* Squash:

Map all users to admin

* Asynchronous:

* Non-privileged port:

Denied

* Cross-mount:

Allowed

Install nfs-common to mount nfs

sudo apt-get install nfs-common

In /etc/fstab mount it with, make sure to ues tabs for separation (no spaces!)

192.168.1.152:/volume1/pullovas /home/wolle/nasghoul    nfs     defaults        0       0

Mount Usb stick

Find device location with fdisk and look for the flash drive, use the exfat-fuse if the stick is exfat formatted. To find out about the filsystem run blkid, then make the mount point and mount the drive.

sudo fdisk -l
sudo apt install exfat-fuse 
sudo blkid 
sudo mkdir /media/<user>/usbreb 
sudo mount /dev/sdc1 /media/<user>/usbreb -o uid=1000

rsync

Copying folders recursively with rsync rsync --recursive --progress -v source/path destination/path

Mountpoint android phone

The phone is mounted to the Computer through mtp and the SD-Card is in the phone ls -lah /var/run/user/1000/gvfs/mtp:host=%5Busb%3A002%2C003%5D/SD\ card

Change screen brightness

Install xbacklight and set screen brightness to 60%

sudo apt-get install xbacklight
xbacklight -get display 60

Install deb package

run sudo dpkg -i <deb-File>.deb

Check installed Ubuntu Version

For Linux Mint

optiplex in Library on  master [$!]
➜ cat /etc/upstream-release/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu Jammy Jellyfish"

optiplex in Library on  master [$!]
➜ cat /usr/lib/os-release
NAME="Linux Mint"
VERSION="21.1 (Vera)"
ID=linuxmint
ID_LIKE="ubuntu debian"
PRETTY_NAME="Linux Mint 21.1"
VERSION_ID="21.1"
HOME_URL="https://www.linuxmint.com/"
SUPPORT_URL="https://forums.linuxmint.com/"
BUG_REPORT_URL="http://linuxmint-troubleshooting-guide.readthedocs.io/en/latest/"
PRIVACY_POLICY_URL="https://www.linuxmint.com/"
VERSION_CODENAME=vera
UBUNTU_CODENAME=jammy

Printing from the commandline

~/Documents pyenv 🐍 system 
➜ lpstat -p -d
printer HP_LaserJet_M15w_0725E9_ is idle.  enabled since Sun 22 Dec 2019 09:37:15 AM EST
printer [email protected] is idle.  enabled since Sun 22 Dec 2019 09:39:27 AM EST
no system default destination

~/Documents pyenv 🐍 system 
➜ lpoptions -d HP_LaserJet_M15w_0725E9_
device-uri=ipps://HP%20LaserJet%20M15w%20(0725E9)._ipps._tcp.local/ printer-info='HP LaserJet M15w (0725E9)' printer-location printer-make-and-model='HP HP LaserJet M14-M17' printer-type=16781316

~/Documents pyenv 🐍 system 
➜ lp D\&B-E-card.pdf                   
request id is HP_LaserJet_M15w_0725E9_-2 (1 file(s))

~/Documents pyenv 🐍 system 
➜

Firewall

Use ufw to allow firewall request for port and protocol.

sudo ufw allow 53
sudo ufw allow 53/tcp
sudo ufw allow 53/udp

PreviousSecurity NextBash

Last updated 11 months ago