[Libguestfs] [PATCH v3 2/6] v2v: ova: don't detect compressed disks, read the OVF instead

[Tomáš Golembiovský]

The information whether the disk is gzip compressed or not is stored
in the OVF. There is no reason to do the detection.

Signed-off-by: Tomáš Golembiovský <tgolembi at redhat.com>
---
 v2v/input_ova.ml          | 28 +++++++++++++++++-----------
 v2v/test-v2v-i-ova-gz.ovf |  2 +-
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/v2v/input_ova.ml b/v2v/input_ova.ml
index b283629..61930f0 100644
--- a/v2v/input_ova.ml
+++ b/v2v/input_ova.ml
@@ -275,6 +275,13 @@ object
             | None -> error (f_"no href in ovf:File (id=%s)") file_ref
             | Some s -> s in
 
+          let expr = sprintf "/ovf:Envelope/ovf:References/ovf:File[@ovf:id='%s']/@ovf:compression" file_ref in
+          let compressed =
+            match xpath_string expr with
+            | None | Some "identity" -> false
+            | Some "gzip" -> true
+            | Some s -> error (f_"unsupported compression in OVF: %s") s in
+
           (* Does the file exist and is it readable? *)
           let filename = ovf_folder // filename in
           Unix.access filename [Unix.R_OK];
@@ -282,17 +289,16 @@ object
           (* The spec allows the file to be gzip-compressed, in which case
            * we must uncompress it into the tmpdir.
            *)
-          let filename =
-            if detect_file_type filename = `GZip then (
-              let new_filename = tmpdir // String.random8 () ^ ".vmdk" in
-              let cmd =
-                sprintf "zcat %s > %s" (quote filename) (quote new_filename) in
-              if shell_command cmd <> 0 then
-                error (f_"error uncompressing %s, see earlier error messages")
-                  filename;
-              new_filename
-            )
-            else filename in
+          let filename = if compressed then (
+            let new_filename = tmpdir // String.random8 () ^ ".vmdk" in
+            let cmd =
+              sprintf "zcat %s > %s" (quote filename) (quote new_filename) in
+            if shell_command cmd <> 0 then
+              error (f_"error uncompressing %s, see earlier error messages")
+                filename;
+            new_filename
+          )
+          else filename in
 
           let disk = {
             s_disk_id = i;
diff --git a/v2v/test-v2v-i-ova-gz.ovf b/v2v/test-v2v-i-ova-gz.ovf
index e10ad2b..4a03e85 100644
--- a/v2v/test-v2v-i-ova-gz.ovf
+++ b/v2v/test-v2v-i-ova-gz.ovf
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Envelope vmw:buildId="build-1750787" xmlns="http://schemas.dmtf.org/ovf/envelope/1" xmlns:cim="http://schemas.dmtf.org/wbem/wscim/1/common" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1" xmlns:rasd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData" xmlns:vmw="http://www.vmware.com/schema/ovf" xmlns:vssd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <References>
-    <File ovf:href="disk1.vmdk.gz" ovf:id="file1" ovf:size="7804077568"/>
+    <File ovf:href="disk1.vmdk.gz" ovf:id="file1" ovf:size="7804077568" ovf:compression="gzip"/>
   </References>
   <DiskSection>
     <Info>Virtual disk information</Info>
-- 
2.10.2