modfinder: Use find_binary_or_raise() to find modprobe

This should fix #53.

Signed-off-by: Andy Lutomirski <luto@kernel.org>

2 files changed, 10 insertions, 3 deletions

diff --git a/virtme/modfinder.py b/virtme/modfinder.py
index d0269b0..88f7df57 100644
--- a/virtme/modfinder.py
+++ b/virtme/modfinder.py
@@ -14,16 +14,16 @@ everything.  The idea is to require very few modules.
 from typing import List
 
 import re
-import shutil
 import subprocess
-import os, os.path
+import os
 import itertools
+from . import util
 
 _INSMOD_RE = re.compile('insmod (.*[^ ]) *$')
 
 def resolve_dep(modalias, root=None, kver=None, moddir=None):
     # /usr/sbin might not be in the path, and modprobe is usually in /usr/sbin
-    modprobe = shutil.which('modprobe') or '/usr/sbin/modprobe'
+    modprobe = util.find_binary_or_raise(['modprobe'])
     args = [modprobe, '--show-depends']
     args += ['-C', '/var/empty']
     if root is not None:
diff --git a/virtme/util.py b/virtme/util.py
index 16b7ef7..cc1787b 100644
--- a/virtme/util.py
+++ b/virtme/util.py
@@ -31,3 +31,10 @@ def find_binary(names: Sequence[str], root: str = '/',
 
     # We give up.
     return None
+
+def find_binary_or_raise(names: Sequence[str], root: str = '/',
+                         use_path: bool = True) -> str:
+    ret = find_binary(names, root=root, use_path=use_path)
+    if ret is None:
+        raise RuntimeError('Could not find %r' % names)
+    return ret