How to change resolution and rotate the screen

[samuelexferri]

I'm on a minimal Debian installation (Only "SSH Server" and "Standard System Utilities" with no DE). I installed only the following packages:

apt install -y --no-install-recommends build-essential ca-certificates cage chromium curl dphys-swapfile fail2ban firmware-realtek gcc git gnupg iptables jq polkitd psmisc resolvconf systemd-timesyncd wireguard wlr-randr xwayland xorg zip

I try to use Cage 1.5.0 (From Debian Testing) with systemd in this way:

tee /etc/systemd/system/cage@.service <<EOF
# This is a system unit for launching Cage with auto-login as the
# user configured here. For this to work, wlroots must be built
# with systemd logind support.

[Unit]
Description=Cage Wayland compositor on %I
# Make sure we are started after logins are permitted. If Plymouth is
# used, we want to start when it is on its way out.
After=systemd-user-sessions.service
# Since we are part of the graphical session, make sure we are started
# before it is complete.
Before=graphical.target
# On systems without virtual consoles, do not start.
ConditionPathExists=/dev/tty0
# D-Bus is necessary for contacting logind, which is required.
Wants=dbus.socket systemd-logind.service
After=dbus.socket systemd-logind.service
# Replace any (a)getty that may have spawned, since we log in
# automatically.
Conflicts=getty@%i.service
After=getty@%i.service

[Service]
Type=simple
ExecStart=/usr/bin/cage -- /usr/bin/chromium --no-first-run --start-fullscreen --start-maximized --fast --fast-start --window-position=0,0 --window-size=1280,800 --no-sandbox --kiosk --incognito --disable --disable-pinch --disable-translate --disable-infobars --disable-suggestions-service --disable-save-password-bubble --disable-session-crashed-bubble --noerrdialogs --password-store=basic --disk-cache-dir=/dev/null --disk-cache-size=1 --overscroll-history-navigation=0 --enable-features=OverlayScrollbar --autoplay-policy=no-user-gesture-required --check-for-update-interval=315360000 "https://google.it/" # TODO: "http://0.0.0.0:8080/"
Restart=always
User=cage
# Log this user with utmp, letting it show up with commands 'w' and
# 'who'. This is needed since we replace (a)getty.
UtmpIdentifier=%I
UtmpMode=user
# A virtual terminal is needed.
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
TTYVTDisallocate=yes
# Fail to start if not controlling the virtual terminal.
StandardInput=tty-fail

# Set up a full (custom) user session for the user, required by Cage.
PAMName=cage

[Install]
WantedBy=graphical.target
# Alias=display-manager.service
DefaultInstance=tty7
EOF

tee /etc/pam.d/cage <<EOF
auth           required        pam_unix.so nullok
account        required        pam_unix.so
session        required        pam_unix.so
session        required        pam_systemd.so
EOF

systemctl daemon-reload
systemctl enable cage@tty1.service
systemctl start cage@tty1.service

systemctl set-default graphical.target # Set systemd's default target to the graphical target

When I boot up, I successfully have Cage running Chromium but the resolution is very big, I can't find a way to set the resolution to 1280x800 on my WTD touchscreen. There is no much documentation for kanshi and wlr-randr.

Thanks in advance

[joggee-fr]

Debian manpages give some hints on how to use wlr-randr. If some Wayland environment variable are well set (especially WAYLAND_DISPLAY), you can just use wlr-randr with no parameter to know which mode / resolution is currently used for your monitor. Then, it is quite easy to modify it looking at manpages.

[bhack]

Is it supposed to be run with another service after the cage service?

[joggee-fr]

@bhack, wlr-randr is a utility you can use manually and I don't think it is supposed to be used as a service. It communicates with the Wayland compositor, here Cage, through a well-defined protocol wlr output management.

On the other side, kanshi is a daemon to manage your preferred configurations according to plugged monitors for example. But I am not a user of this tool (right now).

[bhack]

Ok so if we want to autoconfigure at the boot we need to investigate that daemon.

[joggee-fr]

@samuelexferri, do you consider this issue resolved now?

[MayNiklas]

@samuelexferri I'm trying to solve the same issue. Setting WAYLAND_DISPLAY="wayland-1 wlr-randr --output HDMI-A-1 --transform 90" does not work for me. Can you maybe share your solution?

[joggee-fr]

@MayNiklas, don't you have a double quote issue in your command?

[MayNiklas]

@MayNiklas, don't you have a double quote issue in your command?

Sorry, this was a issue on my side when copying from my NixOS configuration. I'm setting environment variables using the Nix language.

WAYLAND_DISPLAY = "wayland-1 ${pkgs.wlr-randr}/bin/wlr-randr --output HDMI-A-1 --transform 90";

is getting translated into the regular syntax.