The Nightmare of “Manual Installation” at 2 AM
Imagine this: Your boss texts you at midnight saying 20 new employees are starting tomorrow morning. Every laptop must be ready with Ubuntu 22.04, complete with Wi-Fi drivers, VS Code, Docker, and the company VPN. If you sit there plugging in USB drives and typing apt install for every single machine, you’ll definitely be pulling an all-nighter at the office.
When I first switched from CentOS to Ubuntu, I once spent an entire week just trying to synchronize configurations across a fleet of workstations. It’s a massive headache without automation tools. Then, I found Cubic (Custom Ubuntu ISO Creator). It’s not just a tool; it’s a lifesaver that allows you to package everything into a single ISO file. Once installed, it’s ready to use immediately without running a single extra command.
What is Cubic and Why Do Sysadmins Need It?
Cubic is a graphical application that lets you mold an original Ubuntu ISO into a personalized version. Unlike USB boot creation tools, Cubic allows you to enter a chroot environment. Here, you interact with the system as if it were a live OS. You can install software, modify system files, or change the wallpaper as you wish.
Once finished, Cubic packages all your changes into a new ISO file. This method is much safer than running Bash scripts post-installation. Every computer deployed from this ISO will be 100% identical, regardless of the network speed at the time of installation.
Hands-on: 5 Steps to Create an Enterprise-Grade Ubuntu ISO
Step 1: Install Cubic on your Workstation
You need a computer running Ubuntu (or a virtual machine) to get started. Avoid using Windows via WSL, as file permission errors will drive you crazy. Open the Terminal and add the official Cubic PPA:
sudo apt-add-repository ppa:cubic-wizard/release
sudo apt update
sudo apt install cubicStep 2: Initialize the Project and Select the Original ISO
Prepare a working directory with at least 40GB of free space. Cubic will extract the entire ISO here, so storage space is critical. Open Cubic, select this directory, and point it to the original Ubuntu ISO file (e.g., ubuntu-22.04.3-desktop-amd64.iso).
You should rename the build to something like Ubuntu-Enterprise-v1 to make version management easier later on.
Step 3: The Chroot Environment – Your Main Kitchen
After clicking Next, Cubic will bring you into a Terminal window with root privileges. This is the heart of the customization process. The first thing you should always do is update the package list:
apt updateNow, install your standard working toolkit. For example, I usually install Chrome, VS Code, and Docker using the following commands:
# Install basic tools
apt install -y curl wget git vim net-tools
# Download and install Google Chrome
wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
apt install -y ./google-chrome-stable_current_amd64.deb
# Install Docker Engine
apt install -y docker.ioStep 4: Integrate Drivers and Default Configurations
If your company uses specific hardware like Dell XPS or ThinkPad, copy the firmware files into /lib/firmware. This ensures Wi-Fi and Touchpads work out of the box. To pre-configure company DNS, you can edit the configuration file directly:
nano /etc/resolv.conf
# Add corporate DNS hereA small but highly effective tip: leverage the /etc/skel directory. Any file you place here will automatically appear in the Home directory of every new user. This is the best way to pre-install browser bookmarks or professional .zshrc configurations.
Step 5: Select ISO Compression and Publish
Once satisfied, click Next. Cubic will ask you to choose a compression type. If you prioritize installation speed, choose gzip. If you want a compact ISO file for uploading to Google Drive, choose xz. However, note that xz will take significantly longer to build.
Troubleshooting: When the ISO File Exceeds 8GB
I once installed so much software that the ISO exceeded 8GB, making it impossible to fit on a standard USB drive. To avoid this, you must clean up thoroughly before packaging. Run these commands in the Chroot environment:
apt clean
apt autoremove
rm -rf /tmp/*
rm *.debApt logs and caches often take up hundreds of megabytes of useless space. Clear them out to keep your ISO as lean as possible.
Conclusion
Creating a custom ISO with Cubic saves you about 45 minutes for every computer you install. Instead of repeating tedious tasks, use that time to optimize your systems. With just one ISO file and a tool like Ventoy, you can turn the deployment of dozens of computers into a smooth experience. Good luck building your perfect ISO!
