mirror of
https://github.com/libguestfs/libguestfs.git
synced 2026-03-21 22:53:37 +00:00
917550a117
This is now set by default in all supported versions of libguestfs. It's just confusing if the examples refer to it.
65 lines
1.8 KiB
OCaml
65 lines
1.8 KiB
OCaml
(* Example showing how to create a disk image. *)
|
|
|
|
open Unix
|
|
open Printf
|
|
|
|
let output = "disk.img"
|
|
|
|
let () =
|
|
let g = new Guestfs.guestfs () in
|
|
|
|
(* Create a raw-format sparse disk image, 512 MB in size. *)
|
|
let fd = openfile output [O_WRONLY;O_CREAT;O_TRUNC;O_NOCTTY] 0o666 in
|
|
ftruncate fd (512 * 1024 * 1024);
|
|
close fd;
|
|
|
|
(* Set the trace flag so that we can see each libguestfs call. *)
|
|
g#set_trace true;
|
|
|
|
(* Attach the disk image to libguestfs. *)
|
|
g#add_drive_opts ~format:"raw" ~readonly:false output;
|
|
|
|
(* 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.
|
|
*)
|
|
let devices = g#list_devices () in
|
|
if Array.length devices <> 1 then
|
|
failwith "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.
|
|
*)
|
|
let partitions = g#list_partitions () in
|
|
if Array.length partitions <> 1 then
|
|
failwith "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_options "" partitions.(0) "/";
|
|
|
|
(* Create some files and directories. *)
|
|
g#touch "/empty";
|
|
let message = "Hello, world\n" in
|
|
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";
|
|
|
|
(* Note also that handles are automatically closed if they are
|
|
* reaped by the garbage collector. You only need to call close
|
|
* if you want to close the handle right away.
|
|
*)
|
|
g#close ()
|