Ubuntu is the modern, open source operating system on Linux for the enterprise server, desktop, cloud, and IoT.

Command Link to heading

SSH into a server using a private key Link to heading

ssh -i private-key username@ip-address

# e.g. ssh -i .ssh/my_private_key [email protected]

Generate an SSH key with a specific name Link to heading

ssh-keygen -f path-to-save/name

# e.g. ssh-keygen -f ~/.ssh/my_private_key

Install Dcoker Link to heading

sudo apt install -y docker.io

Install Dcoker Compose Link to heading

sudo apt install -y docker-compose

Add current logged in user to docker group Link to heading

sudo usermod -aG docker $USER

Get info about the OS Link to heading

uname -a

Get IP address Link to heading

ip addr

Get firewall status Link to heading

sudo ufw status

Allow traffic Link to heading

sudo ufw allow port

# e.g. sudo ufw allow 8080

Enable/Disable firewall Link to heading

sudo ufw enable/disable

Show running processes Link to heading

ps

Display environment variables Link to heading

env

Modify user account Link to heading

usermod -aG <group> <username>

# e.g. sudo usermod -aG docker $USER

Display user identity information Link to heading

id username

# e.g. id admin

Display memory usage Link to heading

free -h

Show disk usage of file systems Link to heading

df -h

apt vs apt-get Link to heading

Both apt and apt-get are package manager.

The apt command is newer and more user-friendly than apt-get.

LTS Releases Link to heading

List of releases

  • Ubuntu 24.04.2 LTS - Noble Numbat
  • Ubuntu 22.04.5 LTS - Jammy Jellyfish
  • Ubuntu 20.04.6 LTS - Focal Fossa