v2v: Add --print-target to display overlay and target information.

This is analogous to --print-source, except that it prints the overlay
and target disk information.

The output looks like below.  Note there is one overlay and one target
section per disk.

Overlay and Target information (--print-target option):

             overlay file: /home/rjones/d/libguestfs/tmp/v2vovlc687fe.qcow2
      overlay device name: sda
overlay virtual disk size: 6442450944
  overlay source qemu URI: /var/tmp/fedora-27.img

          target file: [qemu] json:{ "file.driver": "nbd", "file.path": "/home/rjones/d/libguestfs/tmp/rhvupload.IWrzO6/nbdkit0.sock", "file.export": "/" }
        target format: raw
target estimated size: 2274060540

v2v/cmdline.ml

@@ -44,6 +44,7 @@ type cmdline = {
   output_format : string option;
   output_name : string option;
   print_source : bool;
+  print_target : bool;
   root_choice : root_choice;
 }
 
@@ -53,6 +54,7 @@ let parse_cmdline () =
   let do_copy = ref true in
   let machine_readable = ref false in
   let print_source = ref false in
+  let print_target = ref false in
   let qemu_boot = ref false in
 
   let input_conn = ref None in
@@ -228,6 +230,8 @@ let parse_cmdline () =
                                     s_"Use password from file";
     [ L"print-source" ], Getopt.Set print_source,
                                     s_"Print source and stop";
+    [ L"print-target" ], Getopt.Set print_target,
+                                    s_"Print target and stop";
     [ L"qemu-boot" ], Getopt.Set qemu_boot, s_"Boot in qemu (-o qemu only)";
     [ L"root" ],     Getopt.String ("ask|... ", set_root_choice),
                                     s_"How to choose root filesystem";
@@ -321,6 +325,7 @@ read the man page virt-v2v(1).
   let output_storage = !output_storage in
   let password_file = !password_file in
   let print_source = !print_source in
+  let print_target = !print_target in
   let qemu_boot = !qemu_boot in
   let root_choice = !root_choice in
   let vddk_options =
@@ -359,6 +364,12 @@ read the man page virt-v2v(1).
     exit 0
   );
 
+  (* Some options cannot be used with --in-place. *)
+  if in_place then (
+    if print_target then
+      error (f_"--in-place and --print-target cannot be used together")
+  );
+
   (* Parse out the password from the password file. *)
   let password =
     match password_file with
@@ -579,6 +590,7 @@ read the man page virt-v2v(1).
     do_copy = do_copy; in_place = in_place; network_map = network_map;
     output_alloc = output_alloc; output_format = output_format;
     output_name = output_name;
-    print_source = print_source; root_choice = root_choice;
+    print_source = print_source; print_target;
+    root_choice = root_choice;
   },
   input, output

v2v/cmdline.mli

@@ -42,6 +42,7 @@ type cmdline = {
   output_format : string option;
   output_name : string option;
   print_source : bool;
+  print_target : bool;
   root_choice : Types.root_choice;
 }
 

v2v/types.ml

@@ -281,11 +281,10 @@ type overlay = {
 }
 
 let string_of_overlay ov =
-  sprintf "\
-ov_overlay_file = %s
-ov_sd = %s
-ov_virtual_size = %Ld
-ov_source = %s
+  sprintf "             overlay file: %s
+      overlay device name: %s
+overlay virtual disk size: %Ld
+  overlay source qemu URI: %s
 "
     ov.ov_overlay_file
     ov.ov_sd
@@ -304,12 +303,9 @@ and target_file =
   | TargetURI of string
 
 let string_of_target t =
-  sprintf "\
-target_file = %s
-target_format = %s
-target_estimated_size = %s
-target_overlay = %s
-target_overlay.ov_source = %s
+  sprintf "          target file: %s
+        target format: %s
+target estimated size: %s
 "
     (match t.target_file with
      | TargetFile s -> "[file] " ^ s
@@ -317,8 +313,6 @@ target_overlay.ov_source = %s
     t.target_format
     (match t.target_estimated_size with
     | None -> "None" | Some i -> Int64.to_string i)
-    t.target_overlay.ov_overlay_file
-    t.target_overlay.ov_source.s_qemu_uri
 
 type target_firmware = TargetBIOS | TargetUEFI
 

v2v/v2v.ml

@@ -150,6 +150,22 @@ let rec main () =
   g#shutdown ();
   g#close ();
 
+  (match conversion_mode with
+   | In_place -> ()
+   | Copying (overlays, targets) ->
+      (* Print overlays/targets and stop. *)
+      if cmdline.print_target then (
+        printf (f_"Overlay and Target information (--print-target option):\n");
+        printf "\n";
+        List.iter (
+          fun (ov, t) ->
+            printf "%s\n" (string_of_overlay ov);
+            printf "%s\n" (string_of_target t)
+        ) (List.combine overlays targets);
+        exit 0
+      )
+  );
+
   (* Copy overlays to target (for [--in-place] this does nothing). *)
   (match conversion_mode with
    | In_place -> ()
@@ -684,6 +700,7 @@ and copy_targets cmdline targets input output =
           message (f_"Copying disk %d/%d to qemu URI %s (%s)")
                   (i+1) nr_disks s t.target_format
       );
+      debug "%s" (string_of_overlay t.target_overlay);
       debug "%s" (string_of_target t);
 
       (* We noticed that qemu sometimes corrupts the qcow2 file on

v2v/virt-v2v.pod

@@ -616,6 +616,11 @@ Print information about the source guest and stop.  This option is
 useful when you are setting up network and bridge maps.
 See L</NETWORKS AND BRIDGES>.
 
+=item B<--print-target>
+
+Print information about the target disk(s) and overlay file(s), and
+stop.
+
 =item B<--qemu-boot>
 
 When using I<-o qemu> only, this boots the guest immediately after