From d7a1c9c0bb074d0e5c1878a38a6b6315d33be89c Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Mon, 12 Feb 2018 16:45:02 +0000

Subject: [PATCH] v2v: Add -o rhv-upload output mode (RHBZ#1557273).

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

This adds a new output mode to virt-v2v.  virt-v2v -o rhv-upload

streams images directly to an oVirt or RHV >= 4 Data Domain using the

oVirt SDK v4.  It is more efficient than -o rhv because it does not

need to go via the Export Storage Domain, and is possible for humans

to use unlike -o vdsm.

The implementation uses the Python SDK (‘ovirtsdk4’ module).  An

nbdkit Python 3 plugin translates NBD calls from qemu into HTTPS

requests to oVirt via the SDK.

(cherry picked from commit cc04573927cca97de60d544d37467e67c25867a7)

---

 .gitignore                                |   3 +

 TODO                                      |  27 ++

 v2v/Makefile.am                           |  30 +-

 v2v/cmdline.ml                            |  41 ++

 v2v/embed.sh                              |  48 +++

 v2v/output_rhv_upload.ml                  | 401 +++++++++++++++++++

 v2v/output_rhv_upload.mli                 |  33 ++

 v2v/output_rhv_upload_createvm_source.mli |  19 +

 v2v/output_rhv_upload_plugin_source.mli   |  19 +

 v2v/output_rhv_upload_precheck_source.mli |  19 +

 v2v/rhv-upload-createvm.py                |  86 +++++

 v2v/rhv-upload-plugin.py                  | 445 ++++++++++++++++++++++

 v2v/rhv-upload-precheck.py                |  73 ++++

 v2v/test-v2v-o-rhv-upload-oo-query.sh     |  38 ++

 v2v/test-v2v-python-syntax.sh             |  45 +++

 v2v/virt-v2v.pod                          | 138 ++++++-

 16 files changed, 1447 insertions(+), 18 deletions(-)

 create mode 100755 v2v/embed.sh

 create mode 100644 v2v/output_rhv_upload.ml

 create mode 100644 v2v/output_rhv_upload.mli

 create mode 100644 v2v/output_rhv_upload_createvm_source.mli

 create mode 100644 v2v/output_rhv_upload_plugin_source.mli

 create mode 100644 v2v/output_rhv_upload_precheck_source.mli

 create mode 100644 v2v/rhv-upload-createvm.py

 create mode 100644 v2v/rhv-upload-plugin.py

 create mode 100644 v2v/rhv-upload-precheck.py

 create mode 100755 v2v/test-v2v-o-rhv-upload-oo-query.sh

 create mode 100755 v2v/test-v2v-python-syntax.sh

diff --git a/.gitignore b/.gitignore

index e67013478..ecdac6df3 100644

--- a/.gitignore

+++ b/.gitignore

@@ -671,6 +671,9 @@ Makefile.in

 /utils/qemu-speed-test/qemu-speed-test

 /v2v/.depend

 /v2v/oUnit-*

+/v2v/output_rhv_upload_createvm_source.ml

+/v2v/output_rhv_upload_plugin_source.ml

+/v2v/output_rhv_upload_precheck_source.ml

 /v2v/real-*.d/

 /v2v/real-*.img

 /v2v/real-*.xml

diff --git a/TODO b/TODO

index 2e37ce67c..d196a3f6b 100644

--- a/TODO

+++ b/TODO

@@ -570,3 +570,30 @@ Subsecond handling in virt-diff, virt-ls

 Handle nanoseconds properly.  You should be able to specify them on

 the command line and display them.

+

+virt-v2v -o rhv-upload

+----------------------

+

+* Set or disable the ticket timeout.  The default is going to be

+  increased (from current 60 seconds), so maybe we won't have to

+  set it.  See also:

+  https://bugzilla.redhat.com/show_bug.cgi?id=1563278

+

+* qcow2 cannot be supported yet because there is not yet any

+  concept in imageio of read+write handles.

+  https://bugzilla.redhat.com/show_bug.cgi?id=1563299

+

+* preallocated cannot be supported yet because imageio doesn't

+  know how to zero the image efficiently, instead it runs an

+  fallocate process which writes to every block and that takes

+  many minutes.

+

+* Really check what insecure/rhv_cafile do and implement it correctly.

+

+* Measure and resolve performance problems.

+

+* Allocated image size is unknown for v2v uploads, but imageio needs

+  to know it.  We pass initial_size == provisioned_size == virtual size.

+  That can't be fixed from the v2v side.

+

+* There are unresolved issues about how to clean up disks on failure.

diff --git a/v2v/Makefile.am b/v2v/Makefile.am

index 5fcfeadba..affc00a8b 100644

--- a/v2v/Makefile.am

+++ b/v2v/Makefile.am

@@ -22,12 +22,19 @@ generator_built = \

 	uefi.mli

 BUILT_SOURCES = \

-	$(generator_built)

+	$(generator_built) \

+	output_rhv_upload_createvm_source.ml \

+	output_rhv_upload_plugin_source.ml \

+	output_rhv_upload_precheck_source.ml

 EXTRA_DIST = \

 	$(SOURCES_MLI) $(SOURCES_ML) $(SOURCES_C) \

 	copy_to_local.ml \

 	copy_to_local.mli \

+	embed-code.sh \

+	rhv-upload-createvm.py \

+	rhv-upload-plugin.py \

+	rhv-upload-precheck.py \

 	v2v_unit_tests.ml \

 	virt-v2v.pod \

 	virt-v2v-copy-to-local.pod

@@ -62,6 +69,10 @@ SOURCES_MLI = \

 	output_null.mli \

 	output_qemu.mli \

 	output_rhv.mli \

+	output_rhv_upload.mli \

+	output_rhv_upload_createvm_source.mli \

+	output_rhv_upload_plugin_source.mli \

+	output_rhv_upload_precheck_source.mli \

 	output_vdsm.mli \

 	parse_ova.mli \

 	parse_ovf_from_ova.mli \

@@ -116,6 +127,10 @@ SOURCES_ML = \

 	output_local.ml \

 	output_qemu.ml \

 	output_rhv.ml \

+	output_rhv_upload_createvm_source.ml \

+	output_rhv_upload_plugin_source.ml \

+	output_rhv_upload_precheck_source.ml \

+	output_rhv_upload.ml \

 	output_vdsm.ml \

 	inspect_source.ml \

 	target_bus_assignment.ml \

@@ -126,6 +141,15 @@ SOURCES_C = \

 	libvirt_utils-c.c \

 	qemuopts-c.c

+# These files are generated and contain rhv-upload-*.py embedded as an

+# OCaml string.

+output_rhv_upload_createvm_source.ml: rhv-upload-createvm.py

+	./embed.sh code $^ $@

+output_rhv_upload_plugin_source.ml: rhv-upload-plugin.py

+	./embed.sh code $^ $@

+output_rhv_upload_precheck_source.ml: rhv-upload-precheck.py

+	./embed.sh code $^ $@

+

 if HAVE_OCAML

 bin_PROGRAMS = virt-v2v virt-v2v-copy-to-local

@@ -295,6 +319,7 @@ TESTS_ENVIRONMENT = $(top_builddir)/run --test

 TESTS = \

 	test-v2v-docs.sh \

+	test-v2v-python-syntax.sh \

 	test-v2v-i-ova-bad-sha1.sh \

 	test-v2v-i-ova-bad-sha256.sh \

 	test-v2v-i-ova-formats.sh \

@@ -308,6 +333,7 @@ TESTS = \

 	test-v2v-i-ova-two-disks.sh \

 	test-v2v-i-vmx.sh \

 	test-v2v-it-vddk-io-query.sh \

+	test-v2v-o-rhv-upload-oo-query.sh \

 	test-v2v-o-vdsm-oo-query.sh \

 	test-v2v-bad-networks-and-bridges.sh

@@ -481,6 +507,7 @@ EXTRA_DIST += \

 	test-v2v-o-null.sh \

 	test-v2v-o-qemu.sh \

 	test-v2v-o-rhv.sh \

+	test-v2v-o-rhv-upload-oo-query.sh \

 	test-v2v-o-vdsm-oo-query.sh \

 	test-v2v-o-vdsm-options.sh \

 	test-v2v-oa-option.sh \

@@ -489,6 +516,7 @@ EXTRA_DIST += \

 	test-v2v-print-source.expected \

 	test-v2v-print-source.sh \

 	test-v2v-print-source.xml \

+	test-v2v-python-syntax.sh \

 	test-v2v-conversion-of.sh \

 	test-v2v-sound.sh \

 	test-v2v-sound.xml \

diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml

index c9b859dd6..6321eb656 100644

--- a/v2v/cmdline.ml

+++ b/v2v/cmdline.ml

@@ -133,6 +133,8 @@ let parse_cmdline () =

     | "disk" | "local" -> output_mode := `Local

     | "null" -> output_mode := `Null

     | "ovirt" | "rhv" | "rhev" -> output_mode := `RHV

+    | "ovirt-upload" | "ovirt_upload" | "rhv-upload" | "rhv_upload" ->

+       output_mode := `RHV_Upload

     | "qemu" -> output_mode := `QEmu

     | "vdsm" -> output_mode := `VDSM

     | s ->

@@ -389,6 +391,16 @@ read the man page virt-v2v(1).

     | `Null -> no_options (); `Null

     | `RHV -> no_options (); `RHV

     | `QEmu -> no_options (); `QEmu

+    | `RHV_Upload ->

+       if is_query then (

+         Output_rhv_upload.print_output_options ();

+         exit 0

+       )

+       else (

+         let rhv_options =

+           Output_rhv_upload.parse_output_options output_options in

+         `RHV_Upload rhv_options

+       )

     | `VDSM ->

        if is_query then (

          Output_vdsm.print_output_options ();

@@ -571,6 +583,35 @@ read the man page virt-v2v(1).

       Output_rhv.output_rhv os output_alloc,

       output_format, output_alloc

+    | `RHV_Upload rhv_options ->

+      let output_conn =

+        match output_conn with

+        | None ->

+           error (f_"-o rhv-upload: use ‘-oc’ to point to the oVirt or RHV server REST API URL, which is usually https://servername/ovirt-engine/api")

+        | Some oc -> oc in

+      (* Output format / sparse must currently be raw+sparse.  We can

+       * change this in future.  See TODO file for details. XXX

+       *)

+      if output_alloc <> Sparse || output_format <> Some "raw" then

+        error (f_"-o rhv-upload: currently you must use ‘-of raw’ and you cannot use ‘-oa preallocated’ with this output mode.  These restrictions will be loosened in a future version.");

+      (* In theory we could make the password optional in future. *)

+      let output_password =

+        match output_password with

+        | None ->

+           error (f_"-o rhv-upload: output password file was not specified, use ‘-op’ to point to a file which contains the password used to connect to the oVirt or RHV server")

+        | Some op -> op in

+      let os =

+        match output_storage with

+        | None ->

+           error (f_"-o rhv-upload: output storage was not specified, use ‘-os’");

+        | Some os -> os in

+      if qemu_boot then

+        error_option_cannot_be_used_in_output_mode "rhv-upload" "--qemu-boot";

+      Output_rhv_upload.output_rhv_upload output_alloc output_conn

+                                          output_password os

+                                          rhv_options,

+      output_format, output_alloc

+

     | `VDSM vdsm_options ->

       if output_password <> None then

         error_option_cannot_be_used_in_output_mode "vdsm" "-op";

diff --git a/v2v/embed.sh b/v2v/embed.sh

new file mode 100755

index 000000000..363d7e2b0

--- /dev/null

+++ b/v2v/embed.sh

@@ -0,0 +1,48 @@

+#!/bin/bash -

+# Embed code or other content into an OCaml file.

+# Copyright (C) 2018 Red Hat Inc.

+#

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 2 of the License, or

+# (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program; if not, write to the Free Software

+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

+

+# Embed code or other content into an OCaml file.

+#

+# It is embedded into a string.  As OCaml string literals have virtually

+# no restrictions on length or content we only have to escape double

+# quotes for backslash characters.

+

+if [ $# -ne 3 ]; then

+    echo "embed.sh identifier input output"

+    exit 1

+fi

+

+set -e

+set -u

+

+ident="$1"

+input="$2"

+output="$3"

+

+rm -f "$output" "$output"-t

+

+exec >"$output"-t

+

+echo "(* Generated by embed.sh from $input *)"

+echo

+echo let "$ident" = '"'

+sed -e 's/\(["\]\)/\\\1/g' < "$input"

+echo '"'

+

+chmod -w "$output"-t

+mv "$output"-t "$output"

diff --git a/v2v/output_rhv_upload.ml b/v2v/output_rhv_upload.ml

new file mode 100644

index 000000000..129461242

--- /dev/null

+++ b/v2v/output_rhv_upload.ml

@@ -0,0 +1,401 @@

+(* virt-v2v

+ * Copyright (C) 2009-2018 Red Hat Inc.

+ *

+ * This program is free software; you can redistribute it and/or modify

+ * it under the terms of the GNU General Public License as published by

+ * the Free Software Foundation; either version 2 of the License, or

+ * (at your option) any later version.

+ *

+ * This program is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+ * GNU General Public License for more details.

+ *

+ * You should have received a copy of the GNU General Public License along

+ * with this program; if not, write to the Free Software Foundation, Inc.,

+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

+ *)

+

+open Printf

+open Unix

+

+open Std_utils

+open Tools_utils

+open Unix_utils

+open Common_gettext.Gettext

+

+open Types

+open Utils

+

+type rhv_options = {

+  rhv_cafile : string;

+  rhv_cluster : string option;

+  rhv_direct : bool;

+  rhv_verifypeer : bool;

+}

+

+let print_output_options () =

+  printf (f_"Output options (-oo) which can be used with -o rhv-upload:

+

+  -oo rhv-cafile=CA.PEM           Set ‘ca.pem’ certificate bundle filename.

+  -oo rhv-cluster=CLUSTERNAME     Set RHV cluster name.

+  -oo rhv-direct[=true|false]     Use direct transfer mode (default: false).

+  -oo rhv-verifypeer[=true|false] Verify server identity (default: false).

+")

+

+let parse_output_options options =

+  let rhv_cafile = ref None in

+  let rhv_cluster = ref None in

+  let rhv_direct = ref false in

+  let rhv_verifypeer = ref false in

+

+  List.iter (

+    function

+    | "rhv-cafile", v ->

+       if !rhv_cafile <> None then

+         error (f_"-o rhv-upload: -oo rhv-cafile set twice");

+       rhv_cafile := Some v

+    | "rhv-cluster", v ->

+       if !rhv_cluster <> None then

+         error (f_"-o rhv-upload: -oo rhv-cluster set twice");

+       rhv_cluster := Some v

+    | "rhv-direct", "" -> rhv_direct := true

+    | "rhv-direct", v -> rhv_direct := bool_of_string v

+    | "rhv-verifypeer", "" -> rhv_verifypeer := true

+    | "rhv-verifypeer", v -> rhv_verifypeer := bool_of_string v

+    | k, _ ->

+       error (f_"-o rhv-upload: unknown output option ‘-oo %s’") k

+  ) options;

+

+  let rhv_cafile =

+    match !rhv_cafile with

+    | Some s -> s

+    | None ->

+       error (f_"-o rhv-upload: must use ‘-oo rhv-cafile’ to supply the path to the oVirt or RHV user’s ‘ca.pem’ file") in

+  let rhv_cluster = !rhv_cluster in

+  let rhv_direct = !rhv_direct in

+  let rhv_verifypeer = !rhv_verifypeer in

+

+  { rhv_cafile; rhv_cluster; rhv_direct; rhv_verifypeer }

+

+let python3 = "python3" (* Defined by PEP 394 *)

+let pidfile_timeout = 30

+let finalization_timeout = 5*60

+

+class output_rhv_upload output_alloc output_conn

+                        output_password output_storage

+                        rhv_options =

+  (* Create a temporary directory which will be deleted on exit. *)

+  let tmpdir =

+    let base_dir = (open_guestfs ())#get_cachedir () in

+    let t = Mkdtemp.temp_dir ~base_dir "rhvupload." in

+    rmdir_on_exit t;

+    t in

+

+  let diskid_file_of_id id = tmpdir // sprintf "diskid.%d" id in

+

+  (* Write the Python precheck, plugin and create VM to a temporary file. *)

+  let precheck =

+    let precheck = tmpdir // "rhv-upload-precheck.py" in

+    with_open_out

+      precheck

+      (fun chan -> output_string chan Output_rhv_upload_precheck_source.code);

+    precheck in

+  let plugin =

+    let plugin = tmpdir // "rhv-upload-plugin.py" in

+    with_open_out

+      plugin

+      (fun chan -> output_string chan Output_rhv_upload_plugin_source.code);

+    plugin in

+  let createvm =

+    let createvm = tmpdir // "rhv-upload-createvm.py" in

+    with_open_out

+      createvm

+      (fun chan -> output_string chan Output_rhv_upload_createvm_source.code);

+    createvm in

+

+  (* Is SELinux enabled and enforcing on the host? *)

+  let have_selinux =

+    0 = Sys.command "getenforce 2>/dev/null | grep -isq Enforcing" in

+

+  (* Check that the Python binary is available. *)

+  let error_unless_python_binary_on_path () =

+    try ignore (which python3)

+    with Executable_not_found _ ->

+      error (f_"no python binary called ‘%s’ can be found on the $PATH")

+            python3

+  in

+

+  (* Check that nbdkit is available and new enough. *)

+  let error_unless_nbdkit_working () =

+    if 0 <> Sys.command "nbdkit --version >/dev/null" then

+      error (f_"nbdkit is not installed or not working.  It is required to use ‘-o rhv-upload’.  See \"OUTPUT TO RHV\" in the virt-v2v(1) manual.");

+

+    (* Check it's a new enough version.  The latest features we

+     * require are ‘--exit-with-parent’ and ‘--selinux-label’, both

+     * added in 1.1.14.  (We use 1.1.16 as the minimum here because

+     * it also adds the selinux=yes|no flag in --dump-config).

+     *)

+    let lines = external_command "nbdkit --help" in

+    let lines = String.concat " " lines in

+    if String.find lines "exit-with-parent" == -1 ||

+       String.find lines "selinux-label" == -1 then

+      error (f_"nbdkit is not new enough, you need to upgrade to nbdkit ≥ 1.1.16")

+  in

+

+  (* Check that the python3 plugin is installed and working

+   * and can load the plugin script.

+   *)

+  let error_unless_nbdkit_python3_working () =

+    let cmd = sprintf "nbdkit %s %s --dump-plugin >/dev/null"

+                      python3 (quote plugin) in

+    if Sys.command cmd <> 0 then

+      error (f_"nbdkit Python 3 plugin is not installed or not working.  It is required if you want to use ‘-o rhv-upload’.

+

+See also \"OUTPUT TO RHV\" in the virt-v2v(1) manual.")

+  in

+

+  (* Check that nbdkit was compiled with SELinux support (for the

+   * --selinux-label option).

+   *)

+  let error_unless_nbdkit_compiled_with_selinux () =

+    let lines = external_command "nbdkit --dump-config" in

+    (* In nbdkit <= 1.1.15 the selinux attribute was not present

+     * at all in --dump-config output so there was no way to tell.

+     * Ignore this case because there will be an error later when

+     * we try to use the --selinux-label parameter.

+     *)

+    if List.mem "selinux=no" (List.map String.trim lines) then

+      error (f_"nbdkit was compiled without SELinux support.  You will have to recompile nbdkit with libselinux-devel installed, or else set SELinux to Permissive mode while doing the conversion.")

+  in

+

+  (* JSON parameters which are invariant between disks. *)

+  let json_params = [

+    "verbose", JSON.Bool (verbose ());

+

+    "output_conn", JSON.String output_conn;

+    "output_password", JSON.String output_password;

+    "output_storage", JSON.String output_storage;

+    "output_sparse", JSON.Bool (match output_alloc with

+                                | Sparse -> true

+                                | Preallocated -> false);

+    "rhv_cafile", JSON.String rhv_options.rhv_cafile;

+    "rhv_cluster",

+      JSON.String (Option.default "Default" rhv_options.rhv_cluster);

+    "rhv_direct", JSON.Bool rhv_options.rhv_direct;

+

+    (* The 'Insecure' flag seems to be a number with various possible

+     * meanings, however we just set it to True/False.

+     *

+     * https://github.com/oVirt/ovirt-engine-sdk/blob/19aa7070b80e60a4cfd910448287aecf9083acbe/sdk/lib/ovirtsdk4/__init__.py#L395

+     *)

+    "insecure", JSON.Bool (not rhv_options.rhv_verifypeer);

+  ] in

+

+  (* nbdkit command line args which are invariant between disks. *)

+  let nbdkit_args =

+    let args = [

+      "nbdkit";

+

+      "--foreground";           (* run in foreground *)

+      "--exit-with-parent";     (* exit when virt-v2v exits *)

+      "--newstyle";             (* use newstyle NBD protocol *)

+      "--exportname"; "/";

+

+      "python3";                (* use the nbdkit Python 3 plugin *)

+      plugin;                   (* Python plugin script *)

+    ] in

+    let args = if verbose () then args @ ["--verbose"] else args in

+    let args =

+      (* label the socket so qemu can open it *)

+      if have_selinux then

+        args @ ["--selinux-label"; "system_u:object_r:svirt_t:s0"]

+      else args in

+    args in

+

+object

+  inherit output

+

+  method precheck () =

+    error_unless_python_binary_on_path ();

+    error_unless_nbdkit_working ();

+    error_unless_nbdkit_python3_working ();

+    if have_selinux then

+      error_unless_nbdkit_compiled_with_selinux ()

+

+  method as_options =

+    "-o rhv-upload" ^

+    (match output_alloc with

+     | Sparse -> "" (* default, don't need to print it *)

+     | Preallocated -> " -oa preallocated") ^

+    sprintf " -oc %s -op %s -os %s"

+            output_conn output_password output_storage

+

+  method supported_firmware = [ TargetBIOS ]

+

+  method prepare_targets source targets =

+    let output_name = source.s_name in

+    let json_params =

+      ("output_name", JSON.String output_name) :: json_params in

+

+    (* Python code prechecks.  These can't run in #precheck because

+     * we need to know the name of the virtual machine.

+     *)

+    let json_param_file = tmpdir // "params.json" in

+    with_open_out

+      json_param_file

+      (fun chan -> output_string chan (JSON.string_of_doc json_params));

+    if run_command [ python3; precheck; json_param_file ] <> 0 then

+      error (f_"failed server prechecks, see earlier errors");

+

+    (* Create an nbdkit instance for each disk and set the

+     * target URI to point to the NBD socket.

+     *)

+    List.map (

+      fun t ->

+        let id = t.target_overlay.ov_source.s_disk_id in

+        let disk_name = sprintf "%s-%03d" output_name id in

+        let json_params =

+          ("disk_name", JSON.String disk_name) :: json_params in

+

+        let disk_format =

+          match t.target_format with

+          | ("raw" | "qcow2") as fmt -> fmt

+          | _ ->

+             error (f_"rhv-upload: -of %s: Only output format ‘raw’ or ‘qcow2’ is supported.  If the input is in a different format then force one of these output formats by adding either ‘-of raw’ or ‘-of qcow2’ on the command line.")

+                   t.target_format in

+        let json_params =

+          ("disk_format", JSON.String disk_format) :: json_params in

+

+        let disk_size = t.target_overlay.ov_virtual_size in

+        let json_params =

+          ("disk_size", JSON.Int64 disk_size) :: json_params in

+

+        (* Ask the plugin to write the disk ID to a special file. *)

+        let diskid_file = diskid_file_of_id id in

+        let json_params =

+          ("diskid_file", JSON.String diskid_file) :: json_params in

+

+        (* Write the JSON parameters to a file. *)

+        let json_param_file = tmpdir // sprintf "params%d.json" id in

+        with_open_out

+          json_param_file

+          (fun chan -> output_string chan (JSON.string_of_doc json_params));

+

+        let sock = tmpdir // sprintf "nbdkit%d.sock" id in

+        let pidfile = tmpdir // sprintf "nbdkit%d.pid" id in

+

+        (* Add common arguments to per-target arguments. *)

+        let args =

+          nbdkit_args @ [ "--pidfile"; pidfile;

+                          "--unix"; sock;

+                          sprintf "params=%s" json_param_file ] in

+

+        (* Print the full command we are about to run when debugging. *)

+        if verbose () then (

+          eprintf "running nbdkit:\n";

+          List.iter (fun arg -> eprintf " %s" (quote arg)) args;

+          prerr_newline ()

+        );

+

+        (* Start an nbdkit instance in the background.  By using

+         * --exit-with-parent we don't have to worry about clean-up.

+         *)

+        let args = Array.of_list args in

+        let pid = fork () in

+        if pid = 0 then (

+          (* Child process (nbdkit). *)

+          execvp "nbdkit" args

+        );

+

+        (* Wait for the pidfile to appear so we know that nbdkit

+         * is listening for requests.

+         *)

+        if not (wait_for_file pidfile pidfile_timeout) then (

+          if verbose () then

+            error (f_"nbdkit did not start up.  See previous debugging messages for problems.")

+          else

+            error (f_"nbdkit did not start up.  There may be errors printed by nbdkit above.

+

+If the messages above are not sufficient to diagnose the problem then add the ‘virt-v2v -v -x’ options and examine the debugging output carefully.")

+        );

+

+        if have_selinux then (

+          (* Note that Unix domain sockets have both a file label and

+           * a socket/process label.  Using --selinux-label above

+           * only set the socket label, but we must also set the file

+           * label.

+           *)

+          ignore (

+              run_command ["chcon"; "system_u:object_r:svirt_image_t:s0";

+                           sock]

+          );

+        );

+        (* ... and the regular Unix permissions, in case qemu is

+         * running as another user.

+         *)

+        chmod sock 0o777;

+

+        (* Tell ‘qemu-img convert’ to write to the nbd socket which is

+         * connected to nbdkit.

+         *)

+        let json_params = [

+          "file.driver", JSON.String "nbd";

+          "file.path", JSON.String sock;

+          "file.export", JSON.String "/";

+        ] in

+        let target_file =

+          TargetURI ("json:" ^ JSON.string_of_doc json_params) in

+        { t with target_file }

+    ) targets

+

+  method create_metadata source targets _ guestcaps inspect target_firmware =

+    (* Get the UUIDs of each disk image.  These files are written

+     * out by the nbdkit plugins on successful finalization of the

+     * transfer.

+     *)

+    let nr_disks = List.length targets in

+    let image_uuids =

+      List.map (

+        fun t ->

+          let id = t.target_overlay.ov_source.s_disk_id in

+          let diskid_file = diskid_file_of_id id in

+          if not (wait_for_file diskid_file finalization_timeout) then

+            error (f_"transfer of disk %d/%d failed, see earlier error messages")

+                  (id+1) nr_disks;

+          let diskid = read_whole_file diskid_file in

+          diskid

+      ) targets in

+

+    (* We don't have the storage domain UUID, but instead we write

+     * in a magic value which the Python code (which can get it)

+     * will substitute.

+     *)

+    let sd_uuid = "@SD_UUID@" in

+

+    (* The volume and VM UUIDs are made up. *)

+    let vol_uuids = List.map (fun _ -> uuidgen ()) targets

+    and vm_uuid = uuidgen () in

+

+    (* Create the metadata. *)

+    let ovf =

+      Create_ovf.create_ovf source targets guestcaps inspect

+                            output_alloc

+                            sd_uuid image_uuids vol_uuids vm_uuid

+                            OVirt in

+    let ovf = DOM.doc_to_string ovf in

+

+    let json_param_file = tmpdir // "params.json" in

+    with_open_out

+      json_param_file

+      (fun chan -> output_string chan (JSON.string_of_doc json_params));

+

+    let ovf_file = tmpdir // "vm.ovf" in

+    with_open_out ovf_file (fun chan -> output_string chan ovf);

+    if run_command [ python3; createvm; json_param_file; ovf_file ] <> 0 then

+      error (f_"failed to create virtual machine, see earlier errors")

+

+end

+

+let output_rhv_upload = new output_rhv_upload