linuxexpert-practice-labs/labs/ubuntu-desktop/4-1-listing-and-upgrading

Ubuntu Desktop 4.1: Listing and upgrading packages

Counting what's installed, upgrading everything but one held package, reading apt's history, and holding a snap's updates.

Before you start

The lab changes nothing; reset takes away the holds you add. The VM needs to reach the Ubuntu archive (and the snap store for task 4). Write answers to the files in /root/lab-answers/.

Tasks

1. Count the installed deb packages, and list the snaps. Write the count to /root/lab-answers/1.
2. Bring every deb package up to date, holding back one package that has an update (or any installed package, if none has).
3. Find out when the last apt command that upgraded packages was run, and by whom. Write its Start-Date (date and time) on line 1 of /root/lab-answers/3, and on line 2 the user, root, or unattended-upgrade for the automatic daily run.
4. Stop a snap from updating for two days, then undo it. If snap list shows no snaps (as on a server), install the small hello snap first. Not graded: check that snap list NAME shows held in Notes, and that after --unhold it doesn't.

Hints

• dpkg -l | grep -c '^ii'; snap list.
• apt update, apt list --upgradable, apt-mark hold, apt upgrade. apt-mark showhold shows the hold, and its dpkg -l line starts with hi. Updates that apt upgrade reports as deferred due to phasing may stay.
• /var/log/apt/history.log: the last entry with an Upgrade: line, its Start-Date, Commandline and Requested-By (only there when the command ran through sudo).
• snap refresh --hold=48h NAME, snap refresh --unhold NAME.