LFS211: LAB 5.8 - VNC Server Autostart - Timeout with provided vncserver@.service

Hi,

I have been trying to create a vncserver@.service and ran into issues that I managed to fix. However, since I fixed it by modifying the service content proposed in the Solutions of the lab 5.8, I propose here the content that made it work:

Static hostname: UbuntuLTS
Chassis: vm
Virtualization: kvm
Operating System: Ubuntu 20.04.2 LTS
Kernel: Linux 5.8.0-44-generic
Architecture: x86-64

vncserver@.service proposed by lab solutions:

/etc/systemd/system$ cat vncserver@.service 
[Unit]
Description=Remote desktop service (VNC) on port :%I
After=syslog.target network.target

[Service]
Type=forking
User=username

ExecStartPre=-/usr/bin/vncserver -kill :%i
ExecStart=/usr/bin/vncserver  :%i  -localhost
PIDFile=/home/username/.vnc/%H:%i.pid
ExecStop=-/usr/bin/vncserver -kill :%i

[Install]
WantedBy=multi-user.target

Performing the systemctl daemon-reload and starting it with systemctl start vncserver@41.service resulted in a timeout:

Job for vncserver@41.service failed because a timeout was exceeded.
See "systemctl status vncserver@41.service" and "journalctl -xe" for details.

Commenting out the both lines:

 # ExecStartPre=-/usr/bin/vncserver -kill :%i
 # PIDFile=/home/username/.vnc/%H:%i.pid

Made the service to start and run properly.

It seems that the first comment is needed as the ExecStartPre fails to kill the (in)-existing vncserver process, while the second comment I am not sure why it was timing out as I do have in my ~/.vnc folder a UbuntuLTS:41.pid, corresponding to the %H:%i.pid

How relevant is that PIDFile line in the service, and why doesnt it work?

Thanks!