Export inspect_linux_kernel in Lib.pm

[libguestfs.git] / perl / lib / Sys / Guestfs / Lib.pm

diff --git a/perl/lib/Sys/Guestfs/Lib.pm b/perl/lib/Sys/Guestfs/Lib.pm
index 72b0f7d..dfa79af 100644 (file)
--- a/perl/lib/Sys/Guestfs/Lib.pm
+++ b/perl/lib/Sys/Guestfs/Lib.pm
@@ -66,7 +66,8 @@ use vars qw(@EXPORT_OK @ISA);
 @ISA = qw(Exporter);
 @EXPORT_OK = qw(open_guest get_partitions resolve_windows_path
   inspect_all_partitions inspect_partition
-  inspect_operating_systems mount_operating_system inspect_in_detail);
+  inspect_operating_systems mount_operating_system inspect_in_detail
+  inspect_linux_kernel);
 
 =head2 open_guest
 
@@ -1330,7 +1331,11 @@ The kernel command line.
 
 =item default
 
-The index of the default configuration in the configs array
+The index of the default configuration in the configs array.
+
+=item grub_fs
+
+The path of the filesystem containing the grub partition.
 
 =back
 
@@ -1435,6 +1440,56 @@ sub _check_for_applications
     $os->{apps} = \@apps;
 }
 
+# Find the path which needs to be prepended to paths in grub.conf to make them
+# absolute
+sub _find_grub_prefix
+{
+    my ($g, $os) = @_;
+
+    my $fses = $os->{filesystems};
+    die("filesystems undefined") unless(defined($fses));
+
+    # Look for the filesystem which contains grub
+    my $grubdev;
+    foreach my $dev (keys(%$fses)) {
+        my $fsinfo = $fses->{$dev};
+        if(exists($fsinfo->{content}) && $fsinfo->{content} eq "linux-grub") {
+            $grubdev = $dev;
+            last;
+        }
+    }
+
+    my $mounts = $os->{mounts};
+    die("mounts undefined") unless(defined($mounts));
+
+    # Find where the filesystem is mounted
+    if(defined($grubdev)) {
+        foreach my $mount (keys(%$mounts)) {
+            if($mounts->{$mount} eq $grubdev) {
+                return "" if($mount eq '/');
+                return $mount;
+            }
+        }
+
+        die("$grubdev defined in filesystems, but not in mounts");
+    }
+
+    # If we didn't find it, look for /boot/grub/menu.lst, then try to work out
+    # what filesystem it's on. We use menu.lst rather than grub.conf because
+    # debian only uses menu.lst, and anaconda creates a symlink for it.
+    die(__"Can't find grub on guest") unless($g->exists('/boot/grub/menu.lst'));
+
+    # Look for the most specific mount point in mounts
+    foreach my $path qw(/boot/grub /boot /) {
+        if(exists($mounts->{$path})) {
+            return "" if($path eq '/');
+            return $path;
+        }
+    }
+
+    die("Couldn't determine which filesystem holds /boot/grub/menu.lst");
+}
+
 sub _check_for_kernels
 {
     my ($g, $os) = @_;
@@ -1443,6 +1498,8 @@ sub _check_for_kernels
         # Iterate over entries in grub.conf, populating $os->{boot}
         # For every kernel we find, inspect it and add to $os->{kernels}
 
+        my $grub = _find_grub_prefix($g, $os);
+
         my @boot_configs;
 
         # We want
@@ -1454,6 +1511,7 @@ sub _check_for_kernels
         #           ->{cmdline} = "ro root=/dev/mapper/vg_mbooth-lv_root rhgb"
         #           ->{initrd}  = \initrd
         #       ->{default} = \config
+        #       ->{grub_fs} = "/boot"
         # Initialise augeas
         $g->aug_init("/", 16);
 
@@ -1474,7 +1532,7 @@ sub _check_for_kernels
 
             # Check we've got a kernel entry
             if(defined($grub_kernel)) {
-                my $path = "/boot$grub_kernel";
+                my $path = "$grub$grub_kernel";
 
                 # Reconstruct the kernel command line
                 my @args = ();
@@ -1494,10 +1552,19 @@ sub _check_for_kernels
                 }
                 $config{cmdline} = join(' ', @args) if(scalar(@args) > 0);
 
-                my $kernel = _inspect_linux_kernel($g, $os, "$path");
+                my $kernel =
+                    inspect_linux_kernel($g, $path, $os->{package_format});
 
                 # Check the kernel was recognised
                 if(defined($kernel)) {
+                    # Put this kernel on the top level kernel list
+                    my $kernels = $os->{kernels};
+                    if(!defined($kernels)) {
+                        $kernels = [];
+                        $os->{kernels} = $kernels;
+                    }
+                    push(@$kernels, $kernel);
+
                     $config{kernel} = $kernel;
 
                     # Look for an initrd entry
@@ -1508,7 +1575,7 @@ sub _check_for_kernels
 
                     unless($@) {
                         $config{initrd} =
-                            _inspect_initrd($g, $os, "/boot$initrd",
+                            _inspect_initrd($g, $os, "$grub$initrd",
                                             $kernel->{version});
                     } else {
                         warn __x("Grub entry {title} does not specify an ".
@@ -1524,6 +1591,7 @@ sub _check_for_kernels
         # Create the top level boot entry
         my %boot;
         $boot{configs} = \@configs;
+        $boot{grub_fs} = $grub;
 
         # Add the default configuration
         eval {
@@ -1541,9 +1609,19 @@ sub _check_for_kernels
     }
 }
 
-sub _inspect_linux_kernel
+=head2 inspect_linux_kernel
+
+ my $kernel_hash = inspect_linux_kernel($g, $vmlinuz_path, $package_format);
+
+inspect_linux_kernel returns a hash describing the target linux kernel. For the
+contents of the hash, see the I<kernels> structure described under
+L</inspect_in_detail>.
+
+=cut
+
+sub inspect_linux_kernel
 {
-    my ($g, $os, $path) = @_;
+    my ($g, $path, $package_format) = @_;
 
     my %kernel = ();
 
@@ -1552,7 +1630,7 @@ sub _inspect_linux_kernel
     # If this is a packaged kernel, try to work out the name of the package
     # which installed it. This lets us know what to install to replace it with,
     # e.g. kernel, kernel-smp, kernel-hugemem, kernel-PAE
-    if($os->{package_format} eq "rpm") {
+    if($package_format eq "rpm") {
         my $package;
         eval { $package = $g->command(['rpm', '-qf', '--qf',
                                        '%{NAME}', $path]); };
@@ -1609,14 +1687,6 @@ sub _inspect_linux_kernel
     # of any kernel module.
     $kernel{arch} = file_architecture ($g, $any_module);
 
-    # Put this kernel on the top level kernel list
-    my $kernels = $os->{kernels};
-    if(!defined($kernels)) {
-        $kernels = [];
-        $os->{kernels} = $kernels;
-    }
-    push(@$kernels, \%kernel);
-
     return \%kernel;
 }