Debian Cheat Sheet

DebianCheatSheet.md

Debian Cheat Sheet

Bash

• Clear bash history

    history -c
    history -w
  

Packages management with apt

• Install a package

    # apt-get install <package>
  

• Remove a package

    # apt-get remove <package>
  

• Update, upgrade and clean in one command line

    # apt-get update && apt-get upgrade && apt-get dist-upgrade && apt-get autoclean && apt-get clean && apt-get autoremove
  

KVM

Installation

• Install the qemu-kvm package with apt-get :

    # apt-get install qemu-kvm libvirt-bin
  

• Add regular user into the kvm and libvirt groups :

    # adduser <youruser> kvm
    # adduser <youruser> libvirt
  

Managing VMs with a GUI

• Install desktop application for managing virtual machines

    # apt-get install virt-manager
  

Compress / shrink a qcow2 image

• First, install the tools for accessing and modifying virtual machine disk images

    # apt-get install libguestfs-tools
  

• Now, run this command :

    # virt-sparsify --compress <source image> <destination image>
  

• Example

    # virt-sparsify --compress arch.qcow2 archbox.qcow2
  

Vagrant with libvirt plugin

This is a Vagrant plugin that adds an Libvirt provider to Vagrant, allowing Vagrant to control and provision machines via Libvirt toolkit. You can find this plugin on Github https://github.com/pradels/vagrant-libvirt.

Vagrant installation for Debian

• Download the Debian package : https://www.vagrantup.com/downloads.html

• Install the downloaded package :

    # dpkg -i vagrant_1.8.1_x86_64.deb
  

Libvirt vagrant plugin installation for Debian

• Install missing development libraries for libxslt, libxml2 and libvirt

    # apt-get install libxslt-dev libxml2-dev libvirt-dev zlib1g-dev
  

• Install vagrant-libvirt using standard Vagrant plugin installation methods

    # vagrant plugin install vagrant-libvirt
  

Miscellaneous

• Find a file in all system

    # find / -name <filename>
  

• Show size of directories

    # du -hs /*
  

• Empty the trash using terminal

    # rm -rf ~/.local/share/Trash/*		
  

• Show opened sessions

    # who
  

• Kill User Session

    # pkill -9 -u <username>
  

• Edit a crontab File

  • Tasks examples

    	0 4 * * * /usr/sbin/backup-manager > /dev/null 2>&1
    	@reboot /etc/emailReboot.sh
    

• Iptables

  • Flush All Rules, Delete All Chains, and Accept All

    	sudo iptables -P INPUT ACCEPT
    	sudo iptables -P FORWARD ACCEPT
    	sudo iptables -P OUTPUT ACCEPT
    

  • Block an IP using iptables

    	iptables -A INPUT -s xx.xx.xx.xx -j DROP
    

  • Block an IP for a specific port

    	iptables -A INPUT -p tcp -s xx.xx.xx.xx --dport PORT -j DROP
    

  • Allow access to an IP

    	iptables -A INPUT -s xx.xx.xx.xx -j ACCEPT
    	iptables -A OUTPUT -d xx.xx.xx.xx -j ACCEPT
    

  • Allow access to an IP to a specific port using iptables

    	iptables -A INPUT -p tcp -s xx.xx.xx.xx --dport PORT -j ACCEPT
    

TODO

create_box.sh ubuntu14.qcow2

vagrant box add archbox.box --name archbox

mkdir archbox

cd archbox

vagrant init archbox vagrant up

virsh pool-list virsh pool-refresh tmp