Casaos installs on Debian stable and ubuntu.

Ubuntu-24.04.3-desktop-amd64.iso .
8 gigabytes of memory.
40 gigabytes of disk space.
Updated on December 6, 2025.

This procedure is based on this example.

Ubuntu ip : 192.168.60.8/24
Casaos version: v0.4.15
Your username: teacher
Your home directory:/home/teacher

UFW firewall.See chapter docker firewall.

80,443,8081:8090,9000,9090,9443/tcp (DOCKER) ALLOW IN    Anywhere  
172.16.0.0/12              ALLOW IN    172.16.0.0/12  
172.16.0.0/12              ALLOW OUT   172.16.0.0/12  
anywhere on eth0           ALLOW FWD   Anywhere on net_dpl_1  
anywhere on eth0           ALLOW FWD   Anywhere on net_jla_2  
anywhere on eth0           ALLOW FWD   Anywhere on net_wps_3  
anywhere on eth0           ALLOW FWD   Anywhere on net_xki_4  
anywhere on eth0           ALLOW FWD   Anywhere on net_wki_5  
  
Postrouting rules  
MASQUERADE  all  --  any    !net_dpl_1  172.18.0.0/16        anywhere  
MASQUERADE  all  --  any    !net_jla_2  172.19.0.0/16        anywhere  
MASQUERADE  all  --  any    !net_wps_3  172.20.0.0/16        anywhere  
MASQUERADE  all  --  any    !net_xki_4  172.21.0.0/16        anywhere  
MASQUERADE  all  --  any    !net_wki_5  172.22.0.0/16        anywhere  

Or you can leave the default Ubuntu firewall.

December 6, 2025, Casaos does not support Docker version 29.1.

Open a terminal console.

sudo apt install curl net-tools vim wget

Add Docker's official GPG key.

sudo install -m 0755 -d /etc/apt/keyrings  
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc  
sudo chmod a+r /etc/apt/keyrings/docker.asc  

Add the repository to Apt sources.
sudo touch /etc/apt/sources.list.d/docker.list
sudo echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu noble stable" > /etc/apt/sources.list.d/docker.list

apt update

Find last docker version 28.
sudo apt list --all-versions docker-ce

Example:
5:28.5.2-1
VERSION_STRING=5:28.5.2-1~ubuntu.24.04~noble

sudo apt install docker-ce=$VERSION_STRING docker-ce-cli=$VERSION_STRING containerd.io docker-buildx-plugin docker-compose-plugin

Freeze these packages so you're no longer up to date.

sudo echo containerd.io  hold | dpkg --set-selections  
sudo echo docker-buildx-plugin   hold | dpkg --set-selections  
sudo echo docker-compose-plugin hold | dpkg --set-selections  
sudo echo docker-ce  hold | dpkg --set-selections  
sudo echo docker-ce-cli   hold | dpkg --set-selections  

sudo systemctl enable --now docker

sudo curl -fsSL https://get.casaos.io| sudo bash

http://192.168.60.8 (ens18).

First access.
http://192.168.60.8
Username : as you want.
Password and confirm password: as you want.
Create.

This version is V0.4.15.

Casaos uses yaml scripts for custom mode.
These scripts are "converted" to docker-compose.xml.
The docker-compose.xml file is located /var/lib/casaos/apps/<apps name>/docker-compose.xml.
You can install the apps from the command line.
sudo docker compose -f /var/lib/casaos/apps/<apps name>/docker-compose.xml up.
You can also edit this docker-compose.xml.
But I strongly advise you to make a backup.
Because.. if you restart the installation from the graphical interface, this file will be rewritten.

You should not accept Casaos updates without having made a backup.
These folders are /var/lib/casaos and /var/lib/docker .