Black Screen after start

[jiru]

Hey all, posting here first to see if you can help me figure out what's up.

I have a need for a centralized desktop environment. I have a central server at home, running headless debian VMs, which are installed without a desktop environment (when put into production, this VM won't have a physical or logical graphical display). Here's my steps:

• I first installed gnome desktop environment with tasksel. So far so good. 
• I set systemctl to boot to text mode and not launch a desktop environment (to save resources when i'm not vnc'ing in). Also, so far so good. 
• I installed tigervnc packages from apt
• as a non-root user not added to sudo group:
  • ran vncpassword and set the password
  • created xstartup in ~/.vnc/ with the following:
    

#!/bin/sh
# Start Gnome 3 Desktop
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
vncconfig -iconic &
dbus-launch --exit-with-session gnome-session &

• As the non-root user, I run: 
  vncserver -depth 24 -geometry 1440x900 -localhost no

Everything works as expected, i can VNC in with the appropriate password to a gui that exits after the vncserver is shutdown. Perfect 

Now, the end goal was to create a docker container. This was going to be deployed in an environment where multiple users would need a container for a short time and then close down. I was inspired by this container but it was built on ubuntu with xfce. I don't want ubuntu or xfce, so i decided to roll my own. 

As the base image, I used https://hub.docker.com/r/jgoerzen/debian-base-minimal, which is exactly what I want. Unlike the debian:buster images, it does run systemd and a number of other traditional unix components. And, It was similar to the container i linked above as the inspiration, just Debian based. 

Here is my dockerfile:

```

FROM jgoerzen/debian-base-minimal

COPY scripts/ /opt/scripts/

RUN apt update \

&& DEBIAN_FRONTEND=noninteractive apt install -y \

--no-install-recommends \

apt-utils \

apt-file \

&& DEBIAN_FRONTEND=noninteractive apt install -y \

wget \

git \

runit \

build-essential \

libssl-dev \

x11-xserver-utils \

dbus-x11 \

dos2unix \

python \

python3 \

python3-distutils \

python3-tk \

python3-dbus \

tigervnc-standalone-server \

tigervnc-xorg-extension \

xauth \

tasksel \

dialog \

&& DEBIAN_FRONTEND=noninteractive tasksel install desktop gnome-desktop \

&& useradd -ms /bin/bash vncuser \

&& mkdir -p /home/vncuser/.vnc/ \

&& mv /opt/scripts/xstartup /home/vncuser/.vnc \

&& chown -R vncuser:vncuser /home/vncuser/.vnc/ /opt/scripts/* \

&& chmod 700 /home/vncuser/.vnc/xstartup \

&& chmod 700 /opt/scripts/*

ENTRYPOINT ["/bin/bash", "/opt/scripts/010.vncsetup.sh"]

```

At the moment, the entrypoint script just sleeps as a place holder. I start the script with: 

docker run -d -p 5901:5901 --stop-signal=SIGRTMIN+3 --tmpfs /run:size=100M --tmpfs /run/lock:size=100M -v /sys/fs/cgroup:/sys/fs/cgroup:ro gdd:latest

After exec'ing into the container, I attempt to reproduce the same setup steps as with my VM:

• su - vncuser (non-root user with no sudo)
• create the xstartup file just as above.
• vncserver -depth 24 -geometry 1440x900 -localhost no

Here is the output:

vncuser@30c00abe898f:~/.vnc$ vncserver -depth 24 -geometry 1440x900 -localhost no

You will require a password to access your desktops.

Password:

Verify:

Would you like to enter a view-only password (y/n)? n

/usr/bin/xauth:  file /home/vncuser/.Xauthority does not exist

New '30c00abe898f:1 (vncuser)' desktop at :1 on machine 30c00abe898f

Starting applications specified in /home/vncuser/.vnc/xstartup

Log file is /home/vncuser/.vnc/30c00abe898f:1.log

Use xtigervncviewer -SecurityTypes VncAuth,TLSVnc -passwd /home/vncuser/.vnc/passwd 30c00abe898f:1 to connect to the VNC server.

And finally, here is the log output:

https://pastebin.com/eFj4HX9q

When i VNC in it's just a black screen. According to the logs, I'm getting a lot of "connection refused" "cannot open display" and "file not found" errors before I even try to connect, so something is really wrong.

Can anyone help me figure out what's missing? I would be most grateful, as this image is last piece to the puzzle for the setup I'm trying to provide for some people who really need it.