ogra@styx:~/Devel/packages/snaps/phonemount$ cat domount 
#! /bin/sh

export PATH=$SNAP/bin:$SNAP/sbin:$SNAP/usr/bin
ARCH="x86_64-linux-gnu"

LC_ALL=C.UTF-8
LANG=C.UTF-8

ID="$SNAP_USER_DATA/id_rsa"
SSHOPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=$SNAP_USER_DATA/known_hosts"


export XDG_DATA_HOME=$SNAP/usr/share
export FONTCONFIG_PATH=$SNAP/etc/fonts/config.d
export FONTCONFIG_FILE=$SNAP/etc/fonts/fonts.conf
export GTK_PATH=$SNAP/usr/lib/$ARCH/gtk-2.0
export GDK_PIXBUF_MODULE_FILE=$SNAP_USER_DATA/.gdk-pixbuf-loaders.cache
export GDK_PIXBUF_MODULEDIR=$SNAP/usr/lib/$ARCH/gdk-pixbuf-2.0/2.10.0/loaders
$SNAP/usr/lib/$ARCH/gdk-pixbuf-2.0/gdk-pixbuf-query-loaders > $GDK_PIXBUF_MODULE_FILE


cd $SNAP/usr/share/zenity
IP=$(zenity --entry --text="Phone IP" 2>/dev/null)
#PWD=$(zenity --password 2>/dev/null)

cd $SNAP_USER_DATA

[ -e "$ID" ] || $SNAP/usr/bin/ssh-keygen -f $ID -t rsa -N '' >/dev/null 2>&1

exec ${SNAP}/usr/bin/ssh -i ${ID} ${SSHOPTS} ${IP} 2>/dev/null
ogra@styx:~/Devel/packages/snaps/phonemount$ 
...

ogra@styx:~/Devel/packages/snaps/phonemount$ cat snapcraft.yaml 
name: phonemount
version: 0.1-1
summary: Mount your Ubuntu phone through ssh
description: GUI tool to mount your Ubuntu phone to a PC if the phone has ssh set up and enabled
confinement: strict

apps:
    phonemount:
      command: domount
      plugs: [home, x11, network, network-bind]

parts:
  domount:
    source: .
    plugin: copy
    files:
      domount: domount
    stage-packages:
      - openssh-client
      - coreutils
      - zenity
ogra@styx:~/Devel/packages/snaps/phonemount$