From 068bbc95b6d0df18294a0d6aa66ee72448f99e0e Mon Sep 17 00:00:00 2001
From: Denis Knauf <deac@denkn.at>
Date: Sat, 26 Oct 2019 22:21:34 +0200
Subject: [PATCH] program-checks (dependencies to qemu, kpartx, ...)

---
 lib/to_lvm_xfs/base.rb     | 27 ++++++++++++++++++++++++---
 lib/to_lvm_xfs/raspbian.rb |  5 ++---
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/lib/to_lvm_xfs/base.rb b/lib/to_lvm_xfs/base.rb
index e0f80b0..aaa9b42 100644
--- a/lib/to_lvm_xfs/base.rb
+++ b/lib/to_lvm_xfs/base.rb
@@ -9,6 +9,15 @@ require 'to_lvm_xfs/structs'
 class ProgrammError < RuntimeError
 end
 
+class Pathname
+	def self.which cmd
+		ENV['PATH'].each do |path|
+			path = Pathname.new( path) + cmd
+			return path  if path.executable?
+		end
+	end
+end
+
 class Base
 	def self.run *args, &exe
 		new( *args).instance_eval &exe
@@ -96,6 +105,11 @@ class Base
 		STDERR.print "\e[0m"
 	end
 
+	def check_program cmd
+		path = Pathname.which cmd
+		raise Error, "#{cmd} not found."  unless path&.executable?
+	end
+
 	attr_reader :sh, :mounted, :looped, :base, :dest, :vgname
 	def initialize *args
 		OptionParser.new do |opts|
@@ -103,6 +117,12 @@ class Base
 			opts.parse! args
 		end
 
+		%w[kpartx parted rsync lvm lvs pvs vgs mkfs.xfs mkfs.vfat dmsetup losetup lsblk blkid].each do |cmd|
+			check_program cmd
+		end
+		@qemu_bin_src = check_program 'qemu-arm-static'
+		raise Error, "@qemu-arm-static not found.  Please install qemu-user-static"  unless @qemu_bin_srci&.executable?
+
 		if :ask == @password
 			v = b = nil
 			require 'io/console'
@@ -127,6 +147,8 @@ class Base
 		@base = Image.new self, 'base', image: @baseimage
 		@dest = Image.new self, 'dest', image: @destination
 
+		@qemu_bin = dest.root.join 'usr/bin/qemu-arm-static'
+
 		STDERR.print <<EOF
 Settings:
      username: #{@username || '(default)'}
@@ -205,10 +227,9 @@ EOF
 		nok = false
 		build
 
-		qemu_bin = dest.root + "usr/bin/qemu-arm-static"
-		if qemu_bin.exist?
+		if @qemu_bin.exist?
 			msg :remove, "/usr/bin/qemu-arm-static"
-			qemu_bin.unlink
+			@qemu_bin.unlink
 		end
 
 	rescue ProgrammError
diff --git a/lib/to_lvm_xfs/raspbian.rb b/lib/to_lvm_xfs/raspbian.rb
index d486284..83d532d 100644
--- a/lib/to_lvm_xfs/raspbian.rb
+++ b/lib/to_lvm_xfs/raspbian.rb
@@ -147,8 +147,7 @@ class Raspbian < Base
 			end
 		end
 
-		qemu_bin = dest.root.join 'usr/bin/qemu-arm-static'
-		qemu_bin.copy '/usr/bin/qemu-arm-static', preserve: true
+		@qemu_bin.copy @qemu_bin_src, preserve: true
 
 		preload, preload_x = dest.root+'etc/ld.so.preload', dest.root+'etc/ld.so.preload.tp'
 		preload.rename preload_x
@@ -193,6 +192,6 @@ class Raspbian < Base
 		ish.system *%w[dpkg-reconfigure raspberrypi-kernel]
 
 		preload_x.rename preload
-		qemu_bin.unlink
+		@qemu_bin.unlink
 	end
 end