linuxexpert-practice-labs/labs/ubuntu-desktop/4-3-package-sources/README.md

Ubuntu Desktop 4.3: Packages from more than one source

Adding and removing a PPA, installing a downloaded .deb with dpkg, and switching a snap between channels.

Before you start

The lab makes sure git is installed and the hello deb isn't (reset puts it back if you had it). The VM needs to reach the Ubuntu archive, Launchpad and the snap store. Write answers to the files in /root/lab-answers/.

Tasks

1. Add the PPA ppa:git-core/ppa, find which version of git it offers, then remove the PPA without upgrading git. Write the PPA's git version to /root/lab-answers/1.
2. Download the hello package with apt-get download hello (in /root), and install the file with dpkg.
3. Install the hello snap from the edge channel, then go back to stable.

Hints

• add-apt-repository ppa:git-core/ppa (it runs apt update for you); apt-cache policy git shows a ppa.launchpadcontent.net line and the Candidate. add-apt-repository --remove ppa:git-core/ppa takes it out again; afterwards /etc/apt/sources.list.d/ has only ubuntu.sources.
• dpkg -i hello_*.deb; dpkg -l hello starts with ii and hello prints Hello, world!.
• snap install hello --edge, snap refresh hello --stable; snap list --all hello shows both revisions.