CentOS 7: Run Ubuntu 18.04's TorBrowser on LXD

#!/bin/sh

sudo yum install -y snapd
sudo ln -s /var/lib/snapd/snap /snap
sudo systemctl enable snapd
sudo systemctl start snapd

#!/bin/sh -e

sudo snap install lxd
sudo gpasswd -a "${USER}" lxd

cat <<EOF | sudo tee /etc/sysctl.d/lxd.conf
user.max_user_namespaces=15076
EOF

# shellcheck disable=SC1091
. /etc/default/grub

if [ -z "${GRUB_CMDLINE_LINUX_DEFAULT}" ]; then
    cat <<EOF | sudo tee -a /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="user_namespace.enable=1 namespace.unpriv_enable=1
EOF
else
    D="${GRUB_CMDLINE_LINUX_DEFAULT} user_namespace.enable=1"
    D="${D} namespace.unpriv_enable=1"
    sudo sed -i /etc/default/grub \
         -e "s;^GRUB_CMDLINE_LINUX_DEFAULT=.*;GRUB_CMDLINE_LINUX_DEFAULT=\"${D}\";g"
fi

if which grub-mkconfig > /dev/null 2>&1; then
    sudo grub-mkconfig -o /boot/grub/grub.cfg
elif which grub2-mkconfig > /dev/null 2>&1; then
    sudo grub2-mkconfig -o /boot/grub/grub.cfg
else
    echo "Add user_namespace.enable=1 namespace.unpriv_enable=1 to grub.cfg."
    exit 0
fi

sudo reboot

#!/bin/sh -ex

# User name and home directory in container. This user runs Tor Browser.
LXD_TORBROWSER_USER="${USER}"
LXD_TORBROWSER_HOME="${HOME}"

# Tor Browser URL.
TORBROWSER_URL=https://www.torproject.org/dist/torbrowser/10.5.2
TORBROWSER_URL="${TORBROWSER_URL}/tor-browser-linux64-10.5.2_en-US.tar.xz"

# Create container which can run GUI application.
cat <<EOF | lxc init ubuntu:18.04 lxd-ubuntu-1804-torbrowser
config:
  environment.DISPLAY: :0
  environment.PULSE_LATENCY_MSEC: "30"
  environment.PULSE_SERVER: /mnt/.pulse-native
  environment.QT_X11_NO_MITSHM: "1"
devices:
  pulse:
    bind: container
    connect: unix:/run/user/1000/pulse/native
    listen: unix:/mnt/.pulse-native
    mode: "0666"
    security.gid: "1000"
    security.uid: "1000"
    type: proxy
  x11:
    bind: container
    connect: unix:@/tmp/.X11-unix/X0
    listen: unix:@/tmp/.X11-unix/X0
    security.gid: "1000"
    security.uid: "1000"
    type: proxy
EOF
lxc start lxd-ubuntu-1804-torbrowser

# Settings on container.
cat <<EOF | lxc exec lxd-ubuntu-1804-torbrowser -- /bin/sh -ex
# Add user who runs Tor Browser.
useradd -m "${LXD_TORBROWSER_USER}" -d "${LXD_TORBROWSER_HOME}"

# Install packages.
apt update -y
apt upgrade -y
apt install -y wget pulseaudio ibus-mozc dbus-x11 firefox fonts-takao
sed -i "s/; enable-shm = yes/enable-shm = no/g" /etc/pulse/client.conf

# The umount.target prevents container reboot on CentOS 7's LXD.
find /lib/systemd/system -maxdepth 1 -type f -exec \
     sed -e 's/umount\.target//g' -i {} \\;
systemctl --system daemon-reload

# Setting for mozc-jp.
su - "${LXD_TORBROWSER_USER}" -c \
    "dconf write /desktop/ibus/general/preload-engines \"['mozc-jp']\""

# Run torbrowser-launcher to download Tor Browser
cat <<eof | su - "${LXD_TORBROWSER_USER}" -c /bin/sh
wget -q "${TORBROWSER_URL}" -O - | tar Jxf -
mv tor-browser_en-US/* "${LXD_TORBROWSER_HOME}"
rmdir tor-browser_en-US
eof

# Create Tor Browser wrapper.
sudo -u "${LXD_TORBROWSER_USER}" mkdir -p "${LXD_TORBROWSER_HOME}/bin"
cat <<eof | sudo -u "${LXD_TORBROWSER_USER}" tee \
"${LXD_TORBROWSER_HOME}/bin/lxd-ubuntu-1804-torbrowser"
#!/bin/sh -e

export DISPLAY=:0
export PULSE_SERVER=unix:/mnt/.pulse-native
export QT4_IM_MODULE=ibus
export QT_IM_MODULE=ibus
export XMODIFIERS="@im=ibus"
export GTK_IM_MODULE=ibus

# If you have already run ibus-daemon -xd, ibus-daemon -xd does nothing.
ibus-daemon -xd

"${LXD_TORBROWSER_HOME}/Browser/start-tor-browser" "\\\$@"
eof
chmod a+x "${LXD_TORBROWSER_HOME}/bin/lxd-ubuntu-1804-torbrowser"
EOF
# lxc restart causes the following error.
# Error: Create restart (for start) operation: Instance is busy running
# a stop operation
lxc stop lxd-ubuntu-1804-torbrowser
lxc start lxd-ubuntu-1804-torbrowser

# Create Tor Browser desktop file on host machine.
PNG="${LXD_TORBROWSER_HOME}/Browser/browser/chrome/icons/default/default128.png"
mkdir -p "${HOME}/.local/share/icons"
lxc file pull lxd-ubuntu-1804-torbrowser"${PNG}" \
    "${HOME}/.local/share/icons/lxd-ubuntu-1804-torbrowser.png"
mkdir -p "${HOME}/.local/share/applications"
cat <<EOF > lxd-ubuntu-1804-torbrowser.desktop
[Desktop Entry]
Version=1.0
Type=Application
Name=LXD Tor Browser
Comment=Run Ubuntu 18.04's Tor Browser on LXD
Categories=Network;WebBrowser;Security;
Icon=${HOME}/.local/share/icons/lxd-ubuntu-1804-torbrowser.png
Exec=lxc exec lxd-ubuntu-1804-torbrowser -- \
su - "${LXD_TORBROWSER_USER}" -c \
"${LXD_TORBROWSER_HOME}/bin/lxd-ubuntu-1804-torbrowser %k"
EOF
desktop-file-install --dir="${HOME}/.local/share/applications" \
                     --delete-original lxd-ubuntu-1804-torbrowser.desktop