#!/usr/bin/perl -w

# Example showing how to create a disk image.

use strict;
use Sys::Guestfs;

my $output = "disk.img";

my $g = new Sys::Guestfs ();

# Create a raw-format sparse disk image, 512 MB in size.
open FILE, ">$output" or die "$output: $!";
truncate FILE, 512 * 1024 * 1024 or die "$output: truncate: $!";
close FILE or die "$output: $!";

# Set the trace flag so that we can see each libguestfs call.
$g->set_trace (1);

# Attach the disk image to libguestfs.
$g->add_drive_opts ($output, format => "raw", readonly => 0);

# Run the libguestfs back-end.
$g->launch ();

# Get the list of devices.  Because we only added one drive
# above, we expect that this list should contain a single
# element.
my @devices = $g->list_devices ();
if (@devices != 1) {
    die "error: expected a single device from list-devices";
}

# Partition the disk as one single MBR partition.
$g->part_disk ($devices[0], "mbr");

# Get the list of partitions.  We expect a single element, which
# is the partition we have just created.
my @partitions = $g->list_partitions ();
if (@partitions != 1) {
    die "error: expected a single partition from list-partitions";
}

# Create a filesystem on the partition.
$g->mkfs ("ext4", $partitions[0]);

# Now mount the filesystem so that we can add files.
$g->mount ($partitions[0], "/");

# Create some files and directories.
$g->touch ("/empty");
my $message = "Hello, world\n";
$g->write ("/hello", $message);
$g->mkdir ("/foo");

# This one uploads the local file /etc/resolv.conf into
# the disk image.
$g->upload ("/etc/resolv.conf", "/foo/resolv.conf");

# Because we wrote to the disk and we want to detect write
# errors, call $g->shutdown.  You don't need to do this:
# $g->close will do it implicitly.
$g->shutdown ();

# Note also that handles are automatically closed if they are
# reaped by reference counting.  You only need to call close
# if you want to close the handle right away.
$g->close ();