## Dockerfile
cat >Dockerfile <<- 'Dockerfile'
# syntax = docker/dockerfile:1.2
FROM myvnc/base
USER root

# X session environment variable
ENV STARTXBIN i3

# Install packages
RUN --mount=type=cache,sharing=locked,target=/var/cache/pacman \
    pacman -Syu --ask 4 --needed \
    tigervnc \
    i3-wm ttf-dejavu \
    && pacman -Scc --ask 4

# i3
COPY 10-tigervnc.sh 90-tigervnc.sh /app/init.d/
RUN chmod +x /app/init.d/*

# Reset user home directory
USER user
WORKDIR /home/user
Dockerfile

## i3/tigervnc Setup
cat >10-tigervnc.sh <<- '10-tigervnc.sh'
#!/usr/bin/env bash
# Check for MYVNC_VNCPASS variable
if [ -z ${MYVNC_VNCPASS} ]
then
    echo "MYVNC_VNCPASS env variable is missing"
    exit 1
fi

# Configure tigervnc auth
if [ ! -f ~/.vnc/passwd ]
then
    echo "${MYVNC_VNCPASS}" | vncpasswd -f >~/.vnc/passwd
    chmod 0600 ~/.vnc/passwd
fi

# Remove VNCPASS env
unset MYVNC_VNCPASS

# VNC xstartup
install /dev/stdin ~/.vnc/xstartup <<- xstartup
#!/usr/bin/env bash
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
exec ${STARTXBIN}
xstartup

# Turn vnc sharing on/off
if [[ ${MYVNC_VNCSHARING} == "true" ]] || [[ ${MYVNC_VNCSHARING} == "1" ]]
then
    _MYVNC_VNCSHARING=alwaysshared
else
    _MYVNC_VNCSHARING=nevershared
fi

# VNC config
cat >~/.vnc/config <<- vncconfig
session=i3
geometry=1920x1080
framerate=60
depth=32
${_MYVNC_VNCSHARING}
vncconfig

# i3 preferences
mkdir -p ~/.config/i3/config.d
cat >~/.config/i3/config <<- 'i3config'
# Font
font pango:DejaVu Sans Mono 8

# Include custom config
include ~/.config/i3/config.d/*.conf

# Binds for killing application
bindsym Mod1+Mod4+Shift+q kill
bindsym Mod1+Mod4+Shift+f fullscreen toggle

# Binds for cycling workspaces
bindsym Mod1+Mod4+Shift+Right workspace next
bindsym Mod1+Mod4+Shift+Left workspace prev

# Locked mode
mode locked {
    bindsym Mod4+Mod1+Escape mode default
}
bindsym Mod4+Mod1+Escape mode locked

# Hide bar permanently
exec --no-startup-id i3-msg bar mode invisible

# Always open window in fullscreen
for_window [all] fullscreen enable
for_window [all] border none
default_border none

# Execute startup script for webapp
exec --no-startup-id /usr/bin/bash ~/.config/i3/startapp.sh
i3config
10-tigervnc.sh

## TigerVNC launch script
cat >90-tigervnc.sh <<- '90-tigervnc.sh'
#!/usr/bin/env bash
# Launch Tigervnc
/usr/bin/dbus-launch vncserver :0 &
90-tigervnc.sh

## Docker build
DOCKER_BUILDKIT=1 docker build ./. \
    --tag myvnc/base:i3 \
    && rm -f Dockerfile *.sh