linuxexpert-practice-labs/labs/ubuntu-server/2-2-meeting-requirements/README.md

Ubuntu Server 2.2: Checking a system meets requirements

A script that checks CPUs, memory, disk space and the release, whether the machine can run VMs, and what already listens on the ports an application wants.

Before you start

The lab starts two services of its own that listen on ports the next application wants, as on a server someone else set up. Reset deletes your check.sh again. Write answers to the files in /root/lab-answers/.

Tasks

1. Write a script check.sh in your home directory that prints PASS or FAIL for each of: at least 2 CPUs, at least 2 GiB of total memory, at least 10 GiB free on /, and Ubuntu 24.04, one line each, in that order. Each result must match what nproc, free -g, df -h / and /etc/os-release show by hand. free -g rounds down, so a VM given exactly 2 GiB shows 1 and fails the memory test.
2. Find out whether this machine could host KVM guests itself (write yes or no to /root/lab-answers/2-kvm), and whether it's a virtual machine (write what systemd-detect-virt prints, such as kvm or none, to /root/lab-answers/2-virt).
3. Find whether anything already listens on TCP port 80 or 5432, and on which addresses. Write one line per listener to /root/lab-answers/3: the port, the address and the program's name, such as 8080 127.0.0.1 python3.

Hints

• nproc, free -g (or MemTotal in /proc/meminfo), df -BG / (or df --output=avail), . /etc/os-release and $VERSION_ID; [ ... ], if, echo.
• lscpu | grep -i virtualization, grep -Ec 'vmx|svm' /proc/cpuinfo; systemd-detect-virt.
• sudo ss -tlnp; 0.0.0.0 means every IPv4 address.