2007-04-03 00:01:18 by steve

Added password role.

roles/passwd

@@ -0,0 +1,188 @@
+#!/usr/bin/perl -w
+
+=head1 NAME
+
+passwd - xen-tools role-script to setup root password for new guests.
+
+=head1 AUTHOR
+
+ Steve
+ --
+ http://www.steve.org.uk/
+
+ $Id: passwd,v 1.1 2007-04-03 00:01:18 steve Exp $
+
+=cut
+
+
+
+use strict;
+use warnings;
+use Digest::MD5;
+use Expect;
+
+
+
+#
+#  Get the arguments our role script was passed.
+#
+my( $prefix, $passwd ) = ( @ARGV );
+
+#
+#  Make sure they are valid.
+#
+if ( ! -d $prefix )
+{
+    print "Prefix not found: $prefix\n";
+    exit;
+}
+
+if ( ! length( $passwd ) )
+{
+    print "Password missing.\n";
+    exit;
+}
+
+
+#
+#  Now make sure we have the module we require.
+#
+eval "use Expect;";
+if ( $@ )
+{
+    print "Expect.pm not found.  Aborting.\n";
+    print "(For Debian systems run:\n\tapt-get install libexpect-perl\n";
+    exit;
+}
+
+
+#
+#  OK now we're good to go:  Continue until it succeeds.
+#
+my $count = 0;
+while( $count < 10 )
+{
+    changePassword( $prefix, $passwd );
+    $count += 1;
+}
+
+print "Failed to setup root password\n";
+print "-----------------------------\n";
+
+
+
+#
+#  Don't look at this code.
+#
+#  OK.  Expect sometimes fails.  It sucks.
+#
+#  So how do we know if a password change operation fails?  We take
+# an MD5(/etc/passwd + /etc/shadow) and if they don't change we've
+# failed.
+#
+#  Upon success we will simply exit();
+#
+#
+sub changePassword
+{
+    my ( $prefix, $passwd ) = ( @_ );
+
+    #
+    # Find current checksum.
+    #
+    my $orig = checksum( $prefix );
+
+    #
+    #  Create the expect object.
+    #
+    my $exp = Expect->spawn( "/usr/sbin/chroot",
+                             $prefix,
+                             "/usr/bin/passwd",
+                             "root" )
+      or die "Cannot spawn the password under chroot: $!\n";
+
+    # prompt
+    unless ($exp->expect(5,"Enter new"))
+    {
+        print "Failed 1st prompt\n";
+        $exp->hard_close();
+        return;
+    }
+
+    # send + wait.
+    $exp->send( $passwd . "\n" );
+    sleep( 1 );
+
+    # confirm
+    unless ($exp->expect(5,"Retype new"))
+    {
+        print "Failed 2nd prompt\n";
+        $exp->hard_close();
+        return;
+    }
+
+    # send.
+    $exp->send( $passwd . "\n" );
+
+
+    #  Closeup.
+    $exp->soft_close();
+
+    #
+    #  Did it work?
+    #
+    my $updated = checksum( $prefix );
+
+    if ( $updated ne $orig )
+    {
+        print "Password setup correctly.\n";
+        exit;
+    }
+    else
+    {
+        print "Setting password failed.\n";
+    }
+}
+
+
+
+#
+#  Checksum /etc/passwd + /etc/shadow if they exist in the
+# given chroot()
+#
+sub checksum
+{
+    my( $prefix ) = ( @_ );
+
+    my $sum = '';
+
+    foreach my $file ( qw! /etc/passwd /etc/shadow ! )
+    {
+        if ( -e $prefix . "/" . $file )
+        {
+            #
+            #  Open the file.
+            #
+            open(FILE, $prefix . "/" . $file) 
+              or die "Can¡Çt open ¡Ç$prefix/$file¡Ç: $!";
+            binmode(FILE);
+
+            #
+            #  Add the data
+            #
+            my $md5 = Digest::MD5->new;
+            while (<FILE>)
+            {
+                $md5->add($_);
+            }
+            close(FILE);
+
+            #
+            #  Update the sum
+            #
+            $sum .= $md5->b64digest;
+        }
+    }
+
+    return $sum;
+}