This is a guide to setup remote SSH into host to startup X server and Sunshine without physical login and dummy plug. The virtual display is accelerated by the NVidia GPU using the TwinView configuration.

The Big Picture

Once you are done, you will need to perform these 3 steps:

1. Turn on the host machine

2. Start Sunshine on remote host with a script that:

   • Edits permissions of /dev/uinput (added sudo config to execute script with no password prompt)
   • Starts X server with startx on virtual display
   • Starts Sunshine
3. Startup Moonlight on the client of interest and connect to host

First we will setup the host and then the SSH Client (Which may not be the same as the machine running the moonlight client).

Host Setup

We will be setting up:

1. Static IP Setup
2. SSH Server Setup
3. Virtual Display Setup
4. Uinput Permissions Workaround
5. Stream Launcher Script

Static IP Setup

Setup static IP Address for host. For LAN connections you can use DHCP reservation within your assigned range. e.g. 192.168.x.x. This will allow you to ssh to the host consistently, so the assigned IP address does not change. It is preferred to set this through your router config.

SSH Server Setup

sudo apt update
sudo apt install openssh-server

sudo pacman -S openssh
# Install openssh-<other_init> if you are not using SystemD
# e.g. sudo pacman -S openssh-runit

sudo apk update
sudo apk add openssh

sudo dnf install openssh-server

sudo yum install openssh-server

Next make sure the OpenSSH daemon is enabled to run when the system starts.

sudo systemctl enable sshd.service
sudo systemctl start sshd.service  # Starts the service now
sudo systemctl status sshd.service  # See if the service is running

sudo ln -s /etc/runit/sv/sshd /run/runit/service  # Enables the OpenSSH daemon to run when system starts
sudo sv start sshd  # Starts the service now
sudo sv status sshd  # See if the service is running

rc-update add sshd  # Enables service
rc-status  # List services to verify sshd is enabled
rc-service sshd start  # Starts the service now

Disabling PAM in sshd

I noticed when the ssh session is disconnected for any reason, pulseaudio would disconnect. This is due to PAM handling sessions. When running dmesg, I noticed elogind would say removed user session. In this Gentoo Forums post, someone had a similar issue. Starting the X server in the background and exiting out of the console would cause your session to be removed.

Edit the sshd_config file with the following to disable PAM.

usePAM no

After making changes to the sshd_config, restart the sshd service for changes to take effect.

sudo sshd -t -f /etc/ssh/sshd_config

sudo systemctl restart sshd.service

sudo sv restart sshd

sudo rc-service sshd restart

Virtual Display Setup

As an alternative to a dummy dongle, you can use this config to create a virtual display.

xrandr | grep " connected" | awk '{ print $1 }'

Section "ServerLayout"
   Identifier "TwinLayout"
   Screen 0 "metaScreen" 0 0
EndSection

Section "Monitor"
   Identifier "Monitor0"
   Option "Enable" "true"
EndSection

Section "Device"
   Identifier "Card0"
   Driver "nvidia"
   VendorName "NVIDIA Corporation"
   Option "MetaModes" "1920x1080"
   Option "ConnectedMonitor" "DP-0"
   Option "ModeValidation" "NoDFPNativeResolutionCheck,NoVirtualSizeCheck,NoMaxPClkCheck,NoHorizSyncCheck,NoVertRefreshCheck,NoWidthAlignmentCheck"
EndSection

Section "Screen"
   Identifier "metaScreen"
   Device "Card0"
   Monitor "Monitor0"
   DefaultDepth 24
   Option "TwinView" "True"
   SubSection "Display"
       Modes "1920x1080"
   EndSubSection
EndSection

Uinput Permissions Workaround

Steps

We can use chown to change the permissions from a script. Since this requires sudo, we will need to update the sudo configuration to execute this without being prompted for a password.

1. Create a sunshine-setup.sh script to update permissions on /dev/uinput. Since we aren’t logged into the host, the udev rule doesn’t apply.
2. Update user sudo configuration /etc/sudoers.d/<user> to allow the sunshine-setup.sh script to be executed with sudo.

Setup Script

This script will take care of any preconditions prior to starting up Sunshine.

Run the following to create a script named something like sunshine-setup.sh:

echo "chown $(id -un):$(id -gn) /dev/uinput" > sunshine-setup.sh && \
  chmod +x sunshine-setup.sh

(Optional) To Ensure ethernet is being used for streaming, you can block Wi-Fi with rfkill.

Run this command to append the rfkill block command to the script:

echo "rfkill block $(rfkill list | grep "Wireless LAN" \
  | sed 's/^\([[:digit:]]\).*/\1/')" >> sunshine-setup.sh

Sudo Configuration

We will manually change the permissions of /dev/uinput using chown. You need to use sudo to make this change, so add/update the entry in /etc/sudoers.d/${USER}.

1. First make a backup of your /etc/sudoers.d/${USER} file.

   sudo cp /etc/sudoers.d/${USER} /etc/sudoers.d/${USER}.backup
   

2. cd to the parent dir of the sunshine-setup.sh script and take note of the full filepath.
3. Execute the following to edit your sudoer config file.

sudo visudo /etc/sudoers.d/${USER}

Copy the below configuration into the text editor. Change ${USER} wherever it occurs to your username (e.g. if your username is sunshineisaawesome you should change ${USER} to sunshineisawesome) or modify the path if you placed sunshine-setup.sh in a different area.

${USER} ALL=(ALL:ALL) ALL, NOPASSWD: /home/${USER}/scripts/sunshine-setup.sh

These changes allow the script to use sudo without being prompted with a password.

e.g. sudo $(pwd)/sunshine-setup.sh

Stream Launcher Script

This is the main entrypoint script that will run the sunshine-setup.sh script, start up X server, and Sunshine. The client will call this script that runs on the host via ssh.

Sunshine Startup Script

This guide will refer to this script as ~/scripts/sunshine.sh. The setup script will be referred as ~/scripts/sunshine-setup.sh.

#!/bin/bash
set -e

export DISPLAY=:0

# Check existing X server
ps -e | grep X >/dev/null
[[ ${?} -ne 0 ]] && {
 echo "Starting X server"
 startx &>/dev/null &
 [[ ${?} -eq 0 ]] && {
   echo "X server started successfully"
 } || echo "X server failed to start"
} || echo "X server already running"

# Check if sunshine is already running
ps -e | grep -e .*sunshine$ >/dev/null
[[ ${?} -ne 0 ]] && {
 sudo ~/scripts/sunshine-setup.sh
 echo "Starting Sunshine!"
 sunshine > /dev/null &
 [[ ${?} -eq 0 ]] && {
   echo "Sunshine started successfully"
 } || echo "Sunshine failed to start"
} || echo "Sunshine is already running"

# Add any other Programs that you want to startup automatically
# e.g.
# steam &> /dev/null &
# firefox &> /dev/null &
# kdeconnect-app &> /dev/null &

SSH Client Setup

We will be setting up:

1. SSH Key Authentication Setup
2. SSH Client Script (Optional)

SSH Key Authentication Setup

1. Setup your SSH keys with ssh-keygen and use ssh-copy-id to authorize remote login to your host. Run ssh <user>@<ip_address> to login to your host. SSH keys automate login so you don’t need to input your password!

2. Optionally setup a ~/.ssh/config file to simplify the ssh command

   Host <some_alias>
       Hostname <ip_address>
       User <username>
       IdentityFile ~/.ssh/<your_private_key>
   

   Now you can use ssh <some_alias>. ssh <some_alias> <commands/script> will execute the command or script on the remote host.

Checkpoint

As a sanity check, let’s make sure your setup is working so far!

Test Steps

With your monitor still plugged into your Sunshine host PC:

1. ssh <alias>
2. ~/scripts/sunshine.sh

3. nvidia-smi

   You should see the Sunshine and Xorg processing running:

   nvidia-smi
   

   Output:

   +---------------------------------------------------------------------------------------+
   | NVIDIA-SMI 535.104.05             Driver Version: 535.104.05   CUDA Version: 12.2     |
   |-----------------------------------------+----------------------+----------------------+
   | GPU  Name                 Persistence-M | Bus-Id        Disp.A | Volatile Uncorr. ECC |
   | Fan  Temp   Perf          Pwr:Usage/Cap |         Memory-Usage | GPU-Util  Compute M. |
   |                                         |                      |               MIG M. |
   |=========================================+======================+======================|
   |   0  NVIDIA GeForce RTX 3070        Off | 00000000:01:00.0  On |                  N/A |
   | 30%   46C    P2              45W / 220W |    549MiB /  8192MiB |      2%      Default |
   |                                         |                      |                  N/A |
   +-----------------------------------------+----------------------+----------------------+
   
   +---------------------------------------------------------------------------------------+
   | Processes:                                                                            |
   |  GPU   GI   CI        PID   Type   Process name                            GPU Memory |
   |        ID   ID                                                             Usage      |
   |=======================================================================================|
   |    0   N/A  N/A      1393      G   /usr/lib/Xorg                                86MiB |
   |    0   N/A  N/A      1440    C+G   sunshine                                    293MiB |
   +---------------------------------------------------------------------------------------+
   

4. Check /dev/uinput permissions

   ls -l /dev/uinput
   

   Output:

   crw------- 1 <user> <primary_group> 10, 223 Aug 29 17:31 /dev/uinput
   

5. Connect to Sunshine host from a moonlight client

Now kill X and Sunshine by running pkill X on the host, unplug your monitors from your GPU, and repeat steps 1 - 5. You should get the same result. With this setup you don’t need to modify the Xorg config regardless if monitors are plugged in or not.

pkill X

SSH Client Script (Optional)

At this point you have a working setup! For convenience, I created this bash script to automate the startup of the X server and Sunshine on the host. This can be run on Unix systems, or on Windows using the git-bash or any bash shell.

For Android/iOS you can install Linux emulators, e.g. Userland for Android and ISH for iOS. The neat part is that you can execute one script to launch Sunshine from your phone or tablet!

#!/bin/bash
set -e

ssh_args="<user>@192.168.X.X" # Or use alias set in ~/.ssh/config

check_ssh(){
  result=1
  # Note this checks infinitely, you could update this to have a max # of retries
  while [[ $result -ne 0 ]]
  do
    echo "checking host..."
    ssh $ssh_args "exit 0" 2>/dev/null
    result=$?
    [[ $result -ne 0 ]] && {
      echo "Failed to ssh to $ssh_args, with exit code $result"
    }
    sleep 3
  done
  echo "Host is ready for streaming!"
}

start_stream(){
  echo "Starting sunshine server on host..."
  echo "Start moonlight on your client of choice"
  # -f runs ssh in the background
  ssh -f $ssh_args "~/scripts/sunshine.sh &"
}

check_ssh
start_stream
exit_code=${?}

sleep 3
exit ${exit_code}

Next Steps

Congratulations, you can now stream your desktop headless! When trying this the first time, keep your monitors close by incase something isn’t working right.