[Libguestfs] [PATCH v2] launch: add support for autodetection of appliance image format
Richard W.M. Jones
rjones at redhat.com
Thu Feb 6 16:16:46 UTC 2020
On Tue, Jun 27, 2017 at 07:42:20PM +0300, Pavel Butsykin wrote:
> This feature allows you to use different image formats for the fixed
> appliance. The raw format is used by default.
I wonder if you're stil using this feature?
Unfortunately because of a recent change in libvirt it is no longer
possible to have a backing file where libvirt will autodetect the
format. See:
https://bugzilla.redhat.com/show_bug.cgi?id=1798148#c3
Therefore the only way to actually do this now would be either for
libguestfs to detect the format (there is an API for this:
guestfs_disk_format), or else to hard code the format in the
./configure option.
In any case I will need to revert this until we can think of something
else (if you still need the feature) because it will simply break with
libvirt >= 6.0.
Rich.
> Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
> ---
> lib/launch-direct.c | 2 ++
> lib/launch-libvirt.c | 19 ++++++++++++-------
> m4/guestfs_appliance.m4 | 11 +++++++++++
> 3 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/lib/launch-direct.c b/lib/launch-direct.c
> index 0be662e25..b9b54857a 100644
> --- a/lib/launch-direct.c
> +++ b/lib/launch-direct.c
> @@ -592,7 +592,9 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
> append_list ("id=appliance");
> append_list ("cache=unsafe");
> append_list ("if=none");
> +#ifndef APPLIANCE_FMT_AUTO
> append_list ("format=raw");
> +#endif
> } end_list ();
> start_list ("-device") {
> append_list ("scsi-hd");
> diff --git a/lib/launch-libvirt.c b/lib/launch-libvirt.c
> index 4adb2cfb3..030ea6911 100644
> --- a/lib/launch-libvirt.c
> +++ b/lib/launch-libvirt.c
> @@ -212,9 +212,10 @@ get_source_format_or_autodetect (guestfs_h *g, struct drive *drv)
>
> /**
> * Create a qcow2 format overlay, with the given C<backing_drive>
> - * (file). The C<format> parameter, which must be non-NULL, is the
> - * backing file format. This is used to create the appliance overlay,
> - * and also for read-only drives.
> + * (file). The C<format> parameter is the backing file format.
> + * The C<format> parameter can be NULL, in this case the backing
> + * format will be determined automatically. This is used to create
> + * the appliance overlay, and also for read-only drives.
> */
> static char *
> make_qcow2_overlay (guestfs_h *g, const char *backing_drive,
> @@ -223,8 +224,6 @@ make_qcow2_overlay (guestfs_h *g, const char *backing_drive,
> char *overlay;
> struct guestfs_disk_create_argv optargs;
>
> - assert (format != NULL);
> -
> if (guestfs_int_lazy_make_tmpdir (g) == -1)
> return NULL;
>
> @@ -232,8 +231,10 @@ make_qcow2_overlay (guestfs_h *g, const char *backing_drive,
>
> optargs.bitmask = GUESTFS_DISK_CREATE_BACKINGFILE_BITMASK;
> optargs.backingfile = backing_drive;
> - optargs.bitmask |= GUESTFS_DISK_CREATE_BACKINGFORMAT_BITMASK;
> - optargs.backingformat = format;
> + if (format) {
> + optargs.bitmask |= GUESTFS_DISK_CREATE_BACKINGFORMAT_BITMASK;
> + optargs.backingformat = format;
> + }
>
> if (guestfs_disk_create_argv (g, overlay, "qcow2", -1, &optargs) == -1) {
> free (overlay);
> @@ -461,7 +462,11 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
>
> /* Note that appliance can be NULL if using the old-style appliance. */
> if (appliance) {
> +#ifdef APPLIANCE_FMT_AUTO
> + params.appliance_overlay = make_qcow2_overlay (g, appliance, NULL);
> +#else
> params.appliance_overlay = make_qcow2_overlay (g, appliance, "raw");
> +#endif
> if (!params.appliance_overlay)
> goto cleanup;
> }
> diff --git a/m4/guestfs_appliance.m4 b/m4/guestfs_appliance.m4
> index 81c43879f..4e1ec8135 100644
> --- a/m4/guestfs_appliance.m4
> +++ b/m4/guestfs_appliance.m4
> @@ -139,3 +139,14 @@ AC_SUBST([GUESTFS_DEFAULT_PATH])
>
> AC_DEFINE_UNQUOTED([GUESTFS_DEFAULT_PATH], ["$GUESTFS_DEFAULT_PATH"],
> [Define guestfs default path.])
> +
> +AC_ARG_ENABLE([appliance-fmt-auto],
> + [AS_HELP_STRING([--enable-appliance-fmt-auto],
> + [enable autodetection of appliance image format @<:@default=no@:>@])],
> + [ENABLE_APPLIANCE_FMT_AUTO="$enableval"],
> + [ENABLE_APPLIANCE_FMT_AUTO=no])
> +
> +if test "x$ENABLE_APPLIANCE_FMT_AUTO" = "xyes"; then
> + AC_DEFINE([APPLIANCE_FMT_AUTO], [1],
> + [Define to 1 if enabled autodetection of appliance image format.])
> +fi
> --
> 2.13.0
>
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--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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