How do I Ubuntu ? - Printable Version

How do I Ubuntu ? - Printable Version
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How do I Ubuntu ? - z3bra - 06-08-2021

Hello folks,

This thread will be a little awkward (for me at least!).
Next monday, I'll have my work laptop reinstalled under stock Ubuntu 21.04, as per my company's policies.

The thing is, I have not used a pre-configured distro in years !
I don't want to use the default Gnome shell, or the default software provided with the distro. I don't mind keeping everything installed though, in case a coworker needs to login on my computer (it'll be connected to the active directory).

So my question will be simple (though the answer might be complex…) :

How do I cleanly change my login session under Ubuntu ?

I basically have my ~/.xsession setup for use with the "xdm" login manager (it is equivalent to an .xinitrc). How do I translate/change it so I can use it under Ubuntu ? I've found that it uses GDM3 and that I'd possibly have to create a .desktop entry to /usr/share/xsessions to launch my own "session script" or whatever. Is that correct ?

Also, Ubuntu 21.04 ships with Wayland by default. Apparently X is still installed, but I'd like to confirm that if anyone has the info.

Help me as the Ubuntu login stack is totally unknown to me, and I don't want to loose too much time setting up my machine next week.

Thanks everyone !

RE: How do I Ubuntu ? - jkl - 06-08-2021

Quote: How do I Ubuntu ?

Please don’t.

RE: How do I Ubuntu ? - z3bra - 06-08-2021

I wish I had the choice.

RE: How do I Ubuntu ? - venam - 08-08-2021

(06-08-2021, 12:36 PM)z3bra Wrote: Next monday, I'll have my work laptop reinstalled under stock Ubuntu 21.04, as per my company's policies.

The thing is, I have not used a pre-configured distro in years !

I'm in a similar situation. What I ended up doing is just use it as is and keep it as updated and close to the default install as possible. It's too much of a hassle to go around all that, especially for a machine that isn't mine. Consider it like it was someone else's machine.

RE: How do I Ubuntu ? - z3bra - 08-08-2021

Mmmmh, for me it's my toolbox, and I spend 7+ hours working with it. I just can't convince myself that gnome-shell is the solution to my problems.

To "work" on this issue, I decided to install it ahead of time, and try to change the session. To my surprise, it is fairly easy to do so !

GDM3 (the default login manager) looks into /usr/share/xsessions for possible "sessions" that can be started by a user. You can create your own, which I named "xsession.desktop":

Code:
[Desktop Entry]

Name=Xsession

Comment=Custom Xsession launcher

Exec=/etc/X11/Xsession

Terminal=False

TryExec=/etc/X11/Xsession

Type=Xsession

The /etc/X11/Xsession script is provided by default on a fresh install. Basically, it will run shell scripts provided in /etc/X11/Xsession.d, based on the content of the file /etc/X11/Xsession.options. One of those option is "allow-user-xsession", which will make the Xsession script run "exec $HOME/.xsession" at the end, which works exactly like .xinitrc when you run "startx".

So in the end I just created 2 files:

/usr/share/xsessions/xsession.desktop
$HOME/.xsession

And I'm back to something I know ! There are still a bunch of thing I need to figure out how to do on Ubuntu (volume management, and the awful combination of "netplan" and "NetworkManager" for network connectivity as an example), but at least I can do so in an environment that I know.

RE: How do I Ubuntu ? - pyratebeard - 09-08-2021

As much as I don't like Ubuntu and Gnome Shell it is nice that you are running native Linux. My current work laptop is running my Linux distro in a VM.

My company is toying with allowing Ubuntu laptops as well, so I will be bookmarking your post for future reference. Thanks for figuring it out for me!

You should keep us updated with how you find using Ubuntu, I for one would be interested.

RE: How do I Ubuntu ? - pkal - 19-08-2021

I don't get what the issue is, why not just work in the default terminal?

RE: How do I Ubuntu ? - z3bra - 22-08-2021

Because my usage of a linux distribution goes beyond typing stuff at a shell. The softwares I'm used to is different from what's shipped by default on Ubuntu.

RE: How do I Ubuntu ? - pkal - 22-08-2021

So then statically compile all you need, bring it along on a USB stick and store it in a local bin directory, or is that not allowed? What specifically are you not used to?

RE: How do I Ubuntu ? - z3bra - 22-08-2021

Window management mostly. And some application launchers that I use (xmenu, sxhkd, dmenu) for which I need the ability to start them when the session starts.
In this regard, there are also a lot of things in the default Gnome shell that prevent my own applications to work as expected. A lot of things that I don't use also.

In a simple way: I don't like the Gnome shell session and want to set it up the way I like.

RE: How do I Ubuntu ? - freem - 26-08-2021

Hum... can't you just summon xinit from a TTY, and use ":1" instead of ":0"?
GDM might keep it's :0, but nothing should prevent you from running a different Xorg session, right?

Of course, here, I assume you're using Xorg, and not wayland. I have no idea if both can coexist and run aside on the same system, nor if ubuntu relies on wayland by default.

RE: How do I Ubuntu ? - z3bra - 30-08-2021

Ubuntu default's session is Xorg, but wayland is supported also.

I didn't want to "hack" around the distro, that is, leave GDM running, change TTY and login+xinit. If I'm stuck with a distro, I might just as well use that to my advantage and learn how to use it.

Just as a note, I'm now fully up and running on my very own session. I got everything setup just as I want, and it was much easier than I initially though. I'll make a separate post to expose my solution !

RE: How do I Ubuntu ? - z3bra - 30-08-2021

So I finally managed to do everything I wanted, and get my very own configuration working. There are multiple key points, so I'll list them here:

X.org session startup

Ubuntu 21.04 ships with GDM3 as its default session manager. On the login screen, you can spot a small gear icon that lets you select the type of session you want. There are 2 choices by default: "Ubuntu" and "Ubuntu on Xorg". I decided to add a 3rd entry: "xsession".

Doing that was fairly easy. I created the following file as "/usr/share/xsession/xsession.desktop":

Code:
[Desktop Entry]

Name=xsession

Comment=Custom Xsession launcher

Exec=/etc/X11/Xsession

Terminal=False

TryExec=/etc/X11/Xsession

Type=Xsession

Upon doing that, and selecting the entry on the login screen, GDM will run the "/etc/X11/Xsession" script, which (among other things) runs the "$HOME/.xsession" script, which you can use to start your session, just like you would do with ".xinitrc".

X.org session

This part was pretty easy. Now that I narrowed my whole session down to a single script, writing that script was easy:

Code:
#!/bin/sh

# $HOME/.xsession

xrdb -merge $HOME/.config/xrdb/ssh-askpass

xidle -timeout 300 -program $HOME/.local/bin/lock &

xsetroot -cursor_name left_ptr

bgs -z $HOME/.bg.jpg

sxhkd -m1 -r /dev/null & # keybinds

glazier & # window management

ewmh & # EWMH support

picom & # compositing

x-widgets & # status bars

rootmenu & # right-click menu (launcher)

safe -rkp '' & # password manager

x-wait # X session holder (basically an infinite loop)

# cleanup session on exit (kill password manager)

kill -TERM $SAFE_PID

rm -f $SAFE_SOCK

Something worth mentioning about /etc/X11/Xsession: by default it tries to source "$HOME/.xsessionrc" before running your script, so it acts like $HOME/.profile. I use it to set my environment variables that are specific to the X session (mostly related to password manager).

Networking

This was the most complex part for me. It's probably because networking is a big part of my job, but I want my networking setup exactly the way I want it. My laptop (like most!) has 2 interfaces: wired and wireless. And I want to be able to seamlessly transition between both, and without disconnection. By default a different IP is assigned for each interface, and when you "switch" connection, you switch IP as well, thus killing all active connections.

I used to run an active/passive bonded connection on my previous debian install: it's a virtual interface that aggregates both the wired and wifi connection, and activate them "on-demand". The mac address of the bonding is that of the primary interface (in my case, the wired one).
This means that when I unplug the cable, the wifi becomes the primary interface, but keeps my current DHCP lease as the MAC address of the bonding interface remains the same. This worked great, and I wanted to replicate it under ubuntu.

Unfortunately, Ubuntu dropped usage on /etc/network/interfaces with release 18.04 I think, so I couldn't just copy my debian config there. The "official" way of configuring the network under Ubuntu seems to be using NetworkManager, and its "nmcli" tool. I have yet to test if I can just drop a file in /etc/NetworkManager to make it work, but for now, I had to do it on the cli (note: bonding a wifi interface is unsupported by NetworkManager, so you need to create a bond with multiple connections: wired, wifi1, wifi2, wifi3, … and add wifi to the bonding as you encounter them. This is ugly, but it works !

Code:
# create bonding interface 

nmcli con add type bond con-name bond0 ifname bond0 bond.options "mode=active-backup,miimon=100,primary=$WIRED"

# add wired interface to the bond

nmcli con add type bond-slave ifname $WIRED master bond0

# add new wifi connection to the bond (this command is wrapped in a "wifi-add" script, to add more wifi connections as time goes)

nmcli cond add type wifi con-name "bond-wifi-$SSID" ifname $WIFI master bond0 ssid "$SSID" wifi-sec.key-mgmt wpa-psk wifi-sec.psk "$WPA_KEY"

And that's it ! I hope this would help someone someday. If not, I learnt something new at least, which is nice.

RE: How do I Ubuntu ? - pyratebeard - 02-09-2021

thanks for that z3bra, it looks more likely that we will be able to get Ubuntu laptops in work so this is handy to know