mirror of
https://github.com/libguestfs/libguestfs.git
synced 2026-03-22 07:03:38 +00:00
123 lines
2.6 KiB
Go
123 lines
2.6 KiB
Go
/* Example showing how to create a disk image. */
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package main
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import (
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"fmt"
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"os"
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"libguestfs.org/guestfs"
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)
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func main() {
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output := "disk.img"
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g, errno := guestfs.Create ()
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if errno != nil {
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panic (errno)
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}
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defer g.Close ()
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/* Create a raw-format sparse disk image, 512 MB in size. */
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f, ferr := os.Create (output)
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if ferr != nil {
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panic (fmt.Sprintf ("could not create file: %s: %s",
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output, ferr))
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}
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defer f.Close ()
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if ferr := f.Truncate (512 * 1024 * 1024); ferr != nil {
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panic (fmt.Sprintf ("could not truncate file: %s", ferr))
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}
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/* Set the trace flag so that we can see each libguestfs call. */
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g.Set_trace (true)
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/* Attach the disk image to libguestfs. */
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optargs := guestfs.OptargsAdd_drive{
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Format_is_set: true,
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Format: "raw",
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Readonly_is_set: true,
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Readonly: false,
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}
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if err := g.Add_drive (output, &optargs); err != nil {
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panic (err)
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}
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/* Run the libguestfs back-end. */
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if err := g.Launch (); err != nil {
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panic (err)
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}
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/* Get the list of devices. Because we only added one drive
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* above, we expect that this list should contain a single
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* element.
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*/
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devices, err := g.List_devices ()
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if err != nil {
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panic (err)
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}
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if len(devices) != 1 {
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panic ("expected a single device from list-devices")
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}
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/* Partition the disk as one single MBR partition. */
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err = g.Part_disk (devices[0], "mbr")
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if err != nil {
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panic (err)
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}
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/* Get the list of partitions. We expect a single element, which
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* is the partition we have just created.
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*/
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partitions, err := g.List_partitions ()
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if err != nil {
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panic (err)
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}
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if len(partitions) != 1 {
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panic ("expected a single partition from list-partitions")
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}
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/* Create a filesystem on the partition. */
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err = g.Mkfs ("ext4", partitions[0], nil)
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if err != nil {
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panic (err)
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}
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/* Now mount the filesystem so that we can add files. */
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err = g.Mount (partitions[0], "/")
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if err != nil {
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panic (err)
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}
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/* Create some files and directories. */
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err = g.Touch ("/empty")
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if err != nil {
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panic (err)
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}
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message := []byte("Hello, world\n")
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err = g.Write ("/hello", message)
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if err != nil {
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panic (err)
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}
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err = g.Mkdir ("/foo")
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if err != nil {
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panic (err)
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}
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/* This one uploads the local file /etc/resolv.conf into
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* the disk image.
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*/
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err = g.Upload ("/etc/resolv.conf", "/foo/resolv.conf")
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if err != nil {
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panic (err)
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}
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/* Because we wrote to the disk and we want to detect write
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* errors, call g:shutdown. You don't need to do this:
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* g.Close will do it implicitly.
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*/
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if err = g.Shutdown (); err != nil {
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panic (fmt.Sprintf ("write to disk failed: %s", err))
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}
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}
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