[pve-devel] [RFC v10 qemu-server/manager] API for disk import and OVF

[Fabian Ebner <f.ebner@proxmox.com>]

Extend qm importdisk/importovf functionality to the API.


Used Dominic's latest version[0] as a starting point. GUI part still
needs to be rebased/updated, so it's not included here.


Changes from v9:

* Split patch into smaller parts

* Some minor (style) fixes/improvements (see individual patches)

* Drop $manifest_only parameter for parse_ovf

    Instead, untaint the path when calling file_size_info, which makes
    the call also work via API which uses the -T switch. If we do want
    to keep $manifest_only, I'd argue that it should also skip the
    file existence check and not only the file size check. Opinions?

* Re-use do_import function

    Rather than duplicating most of it. The down side is the need to
    add a new parameter for skipping configuration update. But I
    suppose the plan is to have qm import switch to the new API at
    some point, and then do_import can be simplified.

* Instead of adding an import-sources parameter to the API, use a new
  import-from property for the disk, that's only available with
  import/alloc-enabled API endpoints via its own version of the schema

    Avoids the split across regular drive key parameters and
    'import_soruces', which avoids quite a bit of cross-checking
    between the two and parsing/passing around the latter.

    The big downsides are:
    * Schema handling is a bit messy.
    * Need to special case print_drive, because we do intermediate
      parse/print to cleanup drive paths. At a first glance, this
      seems not too easy to avoid without complicating things elsewehere.
    * Using the import-aware parse_drive in parse_volume, because that
      is used via the foreach_volume iterators handling the parameters
      of the import-enabled endpoints. Could be avoided by using for
      loops with the import-aware parse_drive instead of
      foreach_volume.

    Counter-arguments for using a single schema (citing Fabian G.):
    * docs/schema dump/api docs: shouldn't look like you can put that
      everywhere where we use the config schema
    * shouldn't have nasty side-effects if someone puts it into the
      config


After all, the 'import-from' disk property approach turned out to be
a uglier than I hoped it would.

My problem with the 'import-sources' API parameter approach (see [0]
for details) is that it requires specifying both
    scsi0: <target storage>:-1,<properties>
    import-sources: scsi0=/path/or/volid/for/source
leading to a not ideal user interface and parameter handling needing
cross-checks to verify that the right combination is specified, and
passing both around at the same time.

Another approach would be adding a new special volid syntax using
    my $IMPORT_DISK_RE = qr!^(([^/:\s]+):)import:(.*)$!;
allowing for e.g.
    qm set 126 -scsi1 rbdkvm:import:myzpool:vm-114-disk-0,aio=native
    qm set 126 -scsi2 rbdkvm:import:/dev/zvol/myzpool/vm-114-disk-1,backup=0
Yes, it's a hack, but it would avoid the pain points from both other
approaches and be very simple. See the end of the mail for a POC.


[0]: https://lists.proxmox.com/pipermail/pve-devel/2021-June/048564.html


pve-manager:

Fabian Ebner (1):
  api: nodes: add readovf endpoint

 PVE/API2/Nodes.pm | 7 +++++++
 1 file changed, 7 insertions(+)


qemu-server:

Dominic Jäger (1):
  api: support VM disk import

Fabian Ebner (6):
  schema: add pve-volume-id-or-absolute-path
  parse ovf: untaint path when calling file_size_info
  api: add endpoint for parsing .ovf files
  image convert: allow block device as source
  schema: drive: use separate schema when disk allocation is possible
  api: create disks: factor out common part from if/else

 PVE/API2/Qemu.pm             | 86 +++++++++++++++++++++++----------
 PVE/API2/Qemu/Makefile       |  2 +-
 PVE/API2/Qemu/OVF.pm         | 55 +++++++++++++++++++++
 PVE/QemuConfig.pm            |  2 +-
 PVE/QemuServer.pm            | 57 +++++++++++++++++++---
 PVE/QemuServer/Drive.pm      | 92 +++++++++++++++++++++++++++---------
 PVE/QemuServer/ImportDisk.pm |  2 +-
 PVE/QemuServer/OVF.pm        |  9 ++--
 8 files changed, 242 insertions(+), 63 deletions(-)
 create mode 100644 PVE/API2/Qemu/OVF.pm

-- 
2.30.2

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 6992f6f..6a22899 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -21,8 +21,9 @@ use PVE::ReplicationConfig;
 use PVE::GuestHelpers;
 use PVE::QemuConfig;
 use PVE::QemuServer;
-use PVE::QemuServer::Drive;
 use PVE::QemuServer::CPUConfig;
+use PVE::QemuServer::Drive;
+use PVE::QemuServer::ImportDisk;
 use PVE::QemuServer::Monitor qw(mon_cmd);
 use PVE::QemuServer::Machine;
 use PVE::QemuMigrate;
@@ -64,6 +65,7 @@ my $resolve_cdrom_alias = sub {
 };
 
 my $NEW_DISK_RE = qr!^(([^/:\s]+):)?(\d+(\.\d+)?)$!;
+my $IMPORT_DISK_RE = qr!^(([^/:\s]+):)import:(.*)$!;
 my $check_storage_access = sub {
    my ($rpcenv, $authuser, $storecfg, $vmid, $settings, $default_storage) = @_;
 
@@ -86,6 +88,9 @@ my $check_storage_access = sub {
 	    my $scfg = PVE::Storage::storage_config($storecfg, $storeid);
 	    raise_param_exc({ storage => "storage '$storeid' does not support vm images"})
 		if !$scfg->{content}->{images};
+	} elsif (!$isCDROM && ($volid =~ $IMPORT_DISK_RE)) {
+	    warn "check access matched: $2 and $3\n";
+	    warn "TODO implement import access check!\n";
 	} else {
 	    PVE::Storage::check_volume_access($rpcenv, $authuser, $storecfg, $vmid, $volid);
 	}
@@ -212,6 +217,29 @@ my $create_disks = sub {
 	    $disk->{size} = PVE::Tools::convert_size($size, 'kb' => 'b');
 	    delete $disk->{format}; # no longer needed
 	    $res->{$ds} = PVE::QemuServer::print_drive($disk);
+	} elsif ($volid =~ $IMPORT_DISK_RE) {
+	    my ($storeid, $source) = ($2, $3);
+
+	    $source = PVE::Storage::abs_filesystem_path($storecfg, $source, 1);
+	    my $src_size = PVE::Storage::file_size_info($source);
+	    die "Could not get file size of $source" if !defined($src_size);
+
+	    my (undef, $dst_volid) = PVE::QemuServer::ImportDisk::do_import(
+		$source,
+		$vmid,
+		$storeid,
+		{
+		    drive_name => $ds,
+		    format => $disk->{format},
+		    'skip-config-update' => 1,
+		},
+	    );
+
+	    push @$vollist, $dst_volid;
+	    $disk->{file} = $dst_volid;
+	    $disk->{size} = $src_size;
+	    delete $disk->{format}; # no longer needed
+	    $res->{$ds} = PVE::QemuServer::print_drive($disk);
 	} else {
 
 	    PVE::Storage::check_volume_access($rpcenv, $authuser, $storecfg, $vmid, $volid);
diff --git a/PVE/QemuServer/ImportDisk.pm b/PVE/QemuServer/ImportDisk.pm
index 51ad52e..7557cac 100755
--- a/PVE/QemuServer/ImportDisk.pm
+++ b/PVE/QemuServer/ImportDisk.pm
@@ -71,7 +71,7 @@ sub do_import {
 	PVE::Storage::activate_volumes($storecfg, [$dst_volid]);
 	PVE::QemuServer::qemu_img_convert($src_path, $dst_volid, $src_size, undef, $zeroinit);
 	PVE::Storage::deactivate_volumes($storecfg, [$dst_volid]);
-	PVE::QemuConfig->lock_config($vmid, $create_drive);
+	PVE::QemuConfig->lock_config($vmid, $create_drive) if !$params->{'skip-config-update'};
     };
     if (my $err = $@) {
 	eval { PVE::Storage::vdisk_free($storecfg, $dst_volid) };
-- 
2.30.2