01: Resolve dependencies in build script, use proper, findable paths

01-installer-iso/build.bash

@@ -6,7 +6,26 @@
 # Distributed under terms of the MIT license.
 #
 
+bindir="$(dirname "$(readlink -f "$0")")"
+pushd "$bindir"
+for prog in dos2unix p7zip cpio genisoimage whois pwgen wget fakeroot /usr/lib/ISOLINUX/isolinux.bin xorriso; do
+	if command -v "$prog" > /dev/null 2>&1 || [ -f "$prog" ]; then continue; else
+		echo "Missing critical dependency: $prog"
+		if sudo apt install dos2unix p7zip-full cpio gzip genisoimage whois pwgen wget fakeroot isolinux xorriso -y; then
+			break
+		else
+			echo "Failed to install critical dependencies"
+			exit 51
+		fi
+	fi
+done
+idfile="$PWD/id_rsa.pub"
+isopath="$(realpath "$PWD/../build")"
+mkdir -p "$isopath" || exit 52
+isofile="$isopath/installer.iso"
+echo "Using SSH key \"$idfile\""
+echo "Writing to file \"$isofile\""
 exec "./linux-unattended-installation/ubuntu/18.04/build-iso.sh" \
-	"id_rsa.pub" \
-	"../build/installer.iso"
+	"$idfile" \
+	"$isofile"