libvirt: add hook support

1. Add a hook support script for libvirt
   Add daemon, qemu, lxc and network script when the correspond to
   libvirt daemon, qemu guest, lxc guest and network started or stoped,
   based on:
   https://libvirt.org/hooks.html

2. Add a qemu user and a qemu group and a kvm group

Signed-off-by: Dengke Du <dengke.du@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/recipes-extended/libvirt/libvirt/hook_support.py b/recipes-extended/libvirt/libvirt/hook_support.py
new file mode 100755
index 00000000..c3eb8b3a
--- /dev/null
+++ b/recipes-extended/libvirt/libvirt/hook_support.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2014 Wind River Systems, Inc. 
+# 
+# Description: Calls other scripts in order, so that there can be multiple
+# scripts for a particular hook tied to libvirt.
+#
+# For example: If this script is called "qemu" and is in the
+# "/etc/libvirt/hooks/" directory.  This script will be called by libvirt
+# when certain actions are performed on a qemu guest.  This script then
+# will in turn call any executable file in the same directory matching
+# "qemu-" followed by at least one alpha-numeric character.  The scripts
+# are called in order (based on the python sorted function), and once any
+# sub-script returns a non-zero exit code no futher scripts are called.
+# This script passes any arguments it retrieves on the command line and a
+# copy of stdin to the sub-scripts it calls.
+
+import os
+import re
+import subprocess
+import sys
+
+def main():
+        return_value = 0
+        hook_name = os.path.basename( __file__ )
+        try:
+                hook_dir = os.path.dirname( __file__ )
+                hook_args = sys.argv
+                del hook_args[ 0 ] # Remove executable from argument list
+
+                # Save stdin, so we can pass it to each sub-script.
+                if sys.stdin.isatty():
+                        stdin_save = [ "" ]
+                else: 
+                        stdin_save = sys.stdin.readlines()
+                # Match the name name of the hook + a dash + atleast
+                # one alpha-numeric character.
+                matcher = re.compile( "%s-\w+" % hook_name )
+                for file_name in sorted( os.listdir( hook_dir ) ):
+                        file_path = os.path.join( hook_dir, file_name )
+                        if matcher.match( file_name ) \
+                           and os.access( file_path, os.X_OK ) \
+                           and os.path.isfile( file_path ) \
+                           and return_value == 0:
+                                cmd = [ file_path ] + hook_args
+                                p = subprocess.Popen( cmd, stdin=subprocess.PIPE )
+                                p.communicate( input = ''.join( stdin_save ) )[0]
+                                return_value = p.wait()
+        except Exception as e:
+                sys.stderr.write( "%s hook error: %s\n" % ( hook_name, str( e ) ) )
+                return_value = 1
+        return return_value
+
+if __name__ == '__main__':
+        sys.exit( main() )