I would like to install Ubuntu 25.04 on a new machine to get a desktop running sway. Other than that, I will need Emacs, a couple of desktop utilities (browser, pdf viewer), and a TeXLive installation.
I also want encryption + btrfs but it is my impression that the installer does that fine these days.
I have been using Debian/Ubuntu for decades so I know my way around apt, but I am not sure about
which flavor I should install (I want an official flavor, not an unofficial “remix”), or should I install the Ubuntu Server Edition and just add the desktop packages?
can I just remove the desktop metapackages I do not need after installing, or maybe skip their installation?
which display manager to pick for just an automatic login, sddm or lightdm or something else?
I’ve not used sway, but I’ve installed labwc several times, which is another Wayland compositor.
I find it easiest just to install Ubuntu server, and then the packages I need on top of that, rather than install an entire desktop and then try to figure which items I need to remove. For a labwc install, I start with labwc, then a taskbar, screenlock and so on. Sway’s wiki on its GitHub site looks like it has useful guidelines.
I’ve not used encryption and btrfs, but if the server is initially installed that way, then I would expect else to just work.
I’ve never set up an automatic login, so can’t comment on that. For the greeter, I use greetd, without any graphical interface at all, but that’s just me; I would expect that any lightweight wayland-compatible greeter would do the job.
Servers and desktop use the same repos. They just make different choices at install time. You only need a very basic server, so if the installer asks you if you want to install various webservers or databases, you’d answer “no”.
Basically, I did exactly what you mention: replicate a desktop by installing a server and then the packages I needed on top of it. If you can, try it in a VM or an old laptop or PC. Then, if it doesn’t work, you can just blow it away and try again. It can be a lot of fun if you like that sort of thing.
All of Ubuntu and official flavors are built using the same software on the same infrastructure; with the only difference being the seed file (ie. formula) which indicates what packages to include… thus you can explore the seed files yourself; OR just contrast manifest files which list the packages (and versions) each ISO was built with.
Of course; the installer can cause different packages to install (or not install if say minimal is chosen) depending on options used at install time, but all of this is changeable post-install; as the real difference is just what packages get installed (my view anyway).
Desktop ISOs install with NetworkManager for networking, where Server ISOs will use Netplan.io but if you install a Server system, then add a desktop on top of that, you may cause the system to change to NetworkManager (or not!) depending on which packages/metapackages you use to install the desktop… thus there can be slight differences as a result of packages you choose to install too.
(( ie. If you were to start on Desktop and remove packages; you’re more likely to end up with NetworkManager for networking, if contrasted with starting with a Server install; but the packages added/removed will control what you’ll get - ie. dependency rules)
I have no experience with sway, so can’t help further… this is just my reaction, and is little beyond what was already provided too.