kmod: Improve logic to find and run virtme-prep-kdir-mods

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

3 files changed, 26 insertions, 3 deletions

diff --git a/virtme/commands/run.py b/virtme/commands/run.py
index 740fb99..8bc353b 100644
--- a/virtme/commands/run.py
+++ b/virtme/commands/run.py
@@ -15,6 +15,7 @@ import sys
 import shlex
 import re
 import itertools
+import pkg_resources
 from .. import virtmods
 from .. import modfinder
 from .. import mkinitramfs
@@ -164,7 +165,7 @@ def find_kernel_and_mods(arch, args):
                     arg_fail("please run virtme-prep-kdir-mods to update virtme's kernel modules directory or use --mods=auto", show_usage=False)
                 else:
                     # Auto-refresh virtme's kernel modules directory
-                    os.system('virtme-prep-kdir-mods')
+                    guest_tools.run_script('virtme-prep-kdir-mods')
             moddir = os.path.join(virtme_mods, 'lib/modules', '0.0.0')
             modfiles = modfinder.find_modules_from_install(
                                virtmods.MODALIASES, root=virtme_mods, kver='0.0.0')
diff --git a/virtme/guest_tools.py b/virtme/guest_tools.py
index 96c1cc2..b84f761 100644
--- a/virtme/guest_tools.py
+++ b/virtme/guest_tools.py
@@ -1,14 +1,16 @@
 # -*- mode: python -*-
 # resources.py: Find virtme's resources
-# Copyright © 2014 Andy Lutomirski
+# Copyright © 2014-2019 Andy Lutomirski
 # Licensed under the GPLv2, which is available in the virtme distribution
 # as a file called LICENSE with SHA-256 hash:
 # 8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643
 
-"""Helpers to find virtme's guest tools."""
+"""Helpers to find virtme's guest tools and host scripts."""
 
 import os
+import shutil
 import pkg_resources
+import subprocess
 
 def find_guest_tools():
     """Return the path of the guest tools installed with the running virtme.
@@ -19,3 +21,22 @@ def find_guest_tools():
 
     # No luck.  This is somewhat surprising.
     return None
+
+def find_script(name):
+    # If we're running out of a source checkout, we can find scripts through
+    # the 'virtme/scripts' symlink.
+    fn = pkg_resources.resource_filename(__name__, 'scripts/%s' % name)
+    if os.path.isfile(fn):
+        return fn
+
+    # Otherwise assume we're actually installed and in PATH.
+    fn = shutil.which(name)
+    if fn is not None:
+        return fn
+
+    # No luck.  This is somewhat surprising.
+    raise Exception('could not find script %s' % name)
+
+def run_script(name):
+    fn = find_script(name)
+    subprocess.check_call(executable=fn, args=[fn])
diff --git a/virtme/scripts b/virtme/scripts
new file mode 120000
index 0000000..19f285a
--- /dev/null
+++ b/virtme/scripts
@@ -0,0 +1 @@
+../bin
\ No newline at end of file