Ubuntu

Internal

• Linux

Info

Ubuntu Version

 lsb_release -a

Package Management

apt-get tutorial

apt-get update

Add a repository:

add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

Query and display available information about installed and installable packages:

apt-cache

User Management

useradd, usermod, etc.

Configuration

Network

Network Interfaces

ifup

ifup is one of the utilities that can be used to configure the network interfaces. It reads its configuration from /etc/network/interfaces:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto ens5
iface ens5 inet static
  address 192.168.1.10
  netmask 255.255.255.0
  gateway 192.168.1.1
  dns-nameservers 1.1.1.1 8.8.8.8 8.8.4.4

DNS

DNS Resolver

DNS resolver is configured with resolvconf, which writes /etc/resolv.conf. Normally, resolvconf is invoked by network interface configuration programs, such as ifup, NetworkManager or dhclient. resolvconf can be run by administrators, but this s normally necessary. /etc/network/interfaces contains DNS-related configuration keywords: "dns-nameserver", "dns-search", "dns-nameservers". For more details

man resolvconf

Execute a Script on Boot

Place the script to be executed in the /etc/init.d directory.

Make it executable.

Execute:

sudo update-rc.d <script-name> defaults

Do not prefix the script name with "/etc/init.d".