Justfile/shell: experiment to verify server via VNC/SSH

Justfile

@@ -99,3 +99,30 @@ disk-umount dir:
 # Perform an offline installation on the mounted target disk, specified by device configuration directory
 disk-install dir: _render_templates
 	just -v _device diskInstall {{dir}} --argstr rebuildarg "dummy"
+
+verify-vnc sshserver attempts="10":
+	#!/usr/bin/env bash
+	set -e
+	export MAGICK_ARGS="-filter Catrom -density 72 -resample 300 -contrast -normalize -despeckle -type grayscale -sharpen 1 -posterize 3 -negate -gamma 100 -blur 1x65535"
+	export TESS_ARGS="-c debug_file=/dev/null --psm 4"
+
+	send_and_compare() {
+		local EXPECT="$(pwgen -0 12)"
+		ssh -4 ${SSHOPTS} root@{{sshserver}} "echo -e '\0033\0143'${EXPECT}>> /dev/tty0" 1>/dev/null 2>&1
+		vncdo --server=${VNCSOCK} --password=${VNCPW} --disable-desktop-resizing --nocursor capture $PWD/screenshot.bmp
+		convert ${MAGICK_ARGS} screenshot.bmp screenshot.tiff
+		tesseract ${TESS_ARGS} screenshot.tiff screenshot
+		grep --quiet ${EXPECT} screenshot.txt
+	}
+
+	trap "E=$?; set +e; rm screenshot.*; echo Exiting...; exit $E" INT TERM HUP
+
+	for i in `seq 1 {{attempts}}`; do
+		if send_and_compare; then
+			echo Verification succeeded at attempt $i. Unlocking remote drive...
+			# TODO: unlock drive
+			exit 0
+		fi
+	done
+	echo Verification failed {{attempts}} times. Giving up...
+	exit 1

shell.nix

@@ -11,6 +11,10 @@ stdenv.mkDerivation {
     git-crypt
     vcsh
     gnupg
+
+    vncdo
+    tesseract
+    imagemagick
   ];
 
   # Set Environment Variables