Libguestfs - Mar 2018 - [PATCH RHEL 7] RHEL 7: -o rhv-upload: Use Python 2 instead of Python

For interest only, here is the patch required to make -o rhv-upload
work with Python 2 (for RHEL 7).  I don't think we want this upstream.
A couple of remarks:

* It's supposed to be possible to add ‘coding: utf-8’ to the top of
  .py files to make Python 2 accept that the file is UTF-8 (otherwise
  it gives an error on loading).  However I added this and it didn't
  appear to make any difference, I still had to replace the Unicode
  quotes with ASCII ones, so I don't know what's going on there.

* The ‘byteify’ function is a bit of a hack, but required here because
  the Python 2 json library returns unicode objects where all the rest
  of the libraries are expecting str.  Not needed in Python 3 of course.

Rich.

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

---
 v2v/output_rhv_upload.ml   | 17 ++++++++---------
 v2v/rhv-upload-createvm.py | 20 ++++++++++++++++----
 v2v/rhv-upload-plugin.py   | 28 ++++++++++++++++++++--------
 v2v/rhv-upload-precheck.py | 22 +++++++++++++++++-----
 4 files changed, 61 insertions(+), 26 deletions(-)

diff --git a/v2v/output_rhv_upload.ml b/v2v/output_rhv_upload.ml
index 7530c0b..cf730bd 100644
--- a/v2v/output_rhv_upload.ml
+++ b/v2v/output_rhv_upload.ml
@@ -26,7 +26,6 @@ open Common_gettext.Gettext
 open Types
 open Utils
 
-let python3 = "python3" (* Defined by PEP 394 *)
 let pidfile_timeout = 30
 let finalization_timeout = 5*60
 
@@ -83,14 +82,14 @@ class output_rhv_upload output_alloc output_conn
       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
+  (* Check that the python plugin is installed and working
    * and can load the plugin script.
    *)
-  let error_unless_nbdkit_python3_working () +  let
error_unless_nbdkit_python_working ()      let cmd = sprintf "nbdkit %s %s
--dump-plugin >/dev/null"
-                      python3 (quote plugin) in
+                      "python" (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’.
+      error (f_"nbdkit Python 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
@@ -138,7 +137,7 @@ See also \"OUTPUT TO RHV\" in the virt-v2v(1)
manual.")
       "--newstyle";             (* use newstyle NBD protocol *)
       "--exportname"; "/";
 
-      "python3";                (* use the nbdkit Python 3 plugin *)
+      "python";                 (* use the nbdkit Python plugin *)
       plugin;                   (* Python plugin script *)
     ] in
     let args = if verbose () then args @ ["--verbose"] else args in
@@ -154,7 +153,7 @@ object
 
   method precheck ()      error_unless_nbdkit_working ();
-    error_unless_nbdkit_python3_working ();
+    error_unless_nbdkit_python_working ();
     if have_selinux then
       error_unless_nbdkit_compiled_with_selinux ()
 
@@ -180,7 +179,7 @@ object
     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
+    if run_command [ "python"; precheck; json_param_file ] <> 0
then
       error (f_"failed server prechecks, see earlier errors");
 
     (* Create an nbdkit instance for each disk and set the
@@ -327,7 +326,7 @@ If the messages above are not sufficient to diagnose the
problem then add the
 
     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
+    if run_command [ "python"; createvm; json_param_file; ovf_file ]
<> 0 then
       error (f_"failed to create virtual machine, see earlier
errors")
 
 end
diff --git a/v2v/rhv-upload-createvm.py b/v2v/rhv-upload-createvm.py
index 612e469..bb23544 100644
--- a/v2v/rhv-upload-createvm.py
+++ b/v2v/rhv-upload-createvm.py
@@ -1,5 +1,6 @@
 # -*- python -*-
-# oVirt or RHV upload create VM used by ‘virt-v2v -o rhv-upload’
+# coding: utf-8
+# oVirt or RHV upload create VM used by 'virt-v2v -o rhv-upload'
 # Copyright (C) 2018 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -23,8 +24,8 @@ import ovirtsdk4.types as types
 import sys
 import time
 
-from http.client import HTTPSConnection
-from urllib.parse import urlparse
+from httplib import HTTPSConnection
+from urlparse import urlparse
 
 # Parameters are passed in via a JSON doc from the OCaml code.
 # Because this Python code ships embedded inside virt-v2v there
@@ -36,8 +37,19 @@ if len(sys.argv) != 3:
     raise RuntimeError("incorrect number of parameters")
 
 # Parameters are passed in via a JSON document.
+# https://stackoverflow.com/a/13105359
+def byteify(input):
+    if isinstance(input, dict):
+        return {byteify(key): byteify(value)
+                for key, value in input.iteritems()}
+    elif isinstance(input, list):
+        return [byteify(element) for element in input]
+    elif isinstance(input, unicode):
+        return input.encode('utf-8')
+    else:
+        return input
 with open(sys.argv[1], 'r') as fp:
-    params = json.load(fp)
+    params = byteify(json.load(fp))
 
 # What is passed in is a password file, read the actual password.
 with open(params['output_password'], 'r') as fp:
diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
index 5568339..91699bf 100644
--- a/v2v/rhv-upload-plugin.py
+++ b/v2v/rhv-upload-plugin.py
@@ -1,5 +1,6 @@
 # -*- python -*-
-# oVirt or RHV upload nbdkit plugin used by ‘virt-v2v -o rhv-upload’
+# coding: utf-8
+# oVirt or RHV upload nbdkit plugin used by 'virt-v2v -o rhv-upload'
 # Copyright (C) 2018 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -16,7 +17,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-import builtins
+from __builtin__ import open as builtin_open
 import json
 import logging
 import ovirtsdk4 as sdk
@@ -25,8 +26,8 @@ import ssl
 import sys
 import time
 
-from http.client import HTTPSConnection
-from urllib.parse import urlparse
+from httplib import HTTPSConnection
+from urlparse import urlparse
 
 # Timeout to wait for oVirt disks to change status, or the transfer
 # object to finish initializing [seconds].
@@ -35,14 +36,25 @@ timeout = 5*60
 # Parameters are passed in via a JSON doc from the OCaml code.
 # Because this Python code ships embedded inside virt-v2v there
 # is no formal API here.
+# https://stackoverflow.com/a/13105359
+def byteify(input):
+    if isinstance(input, dict):
+        return {byteify(key): byteify(value)
+                for key, value in input.iteritems()}
+    elif isinstance(input, list):
+        return [byteify(element) for element in input]
+    elif isinstance(input, unicode):
+        return input.encode('utf-8')
+    else:
+        return input
 params = None
 
 def config(key, value):
     global params
 
     if key == "params":
-        with builtins.open(value, 'r') as fp:
-            params = json.load(fp)
+        with builtin_open(value, 'r') as fp:
+            params = byteify(json.load(fp))
     else:
         raise RuntimeError("unknown configuration key '%s'" %
key)
 
@@ -56,7 +68,7 @@ def open(readonly):
     username = parsed.username or "admin@internal"
 
     # Read the password from file.
-    with builtins.open(params['output_password'], 'r') as fp:
+    with builtin_open(params['output_password'], 'r') as fp:
         password = fp.read()
     password = password.rstrip()
 
@@ -242,7 +254,7 @@ def close(h):
         transfer_service.finalize()
 
         # Write the disk ID file.  Only do this on successful completion.
-        with builtins.open(params['diskid_file'], 'w') as fp:
+        with builtin_open(params['diskid_file'], 'w') as fp:
             fp.write(disk.id)
 
     # Otherwise if we did fail then we should delete the disk.
diff --git a/v2v/rhv-upload-precheck.py b/v2v/rhv-upload-precheck.py
index e3fa651..0c02d2f 100644
--- a/v2v/rhv-upload-precheck.py
+++ b/v2v/rhv-upload-precheck.py
@@ -1,5 +1,6 @@
 # -*- python -*-
-# oVirt or RHV pre-upload checks used by ‘virt-v2v -o rhv-upload’
+# coding: utf-8
+# oVirt or RHV pre-upload checks used by 'virt-v2v -o rhv-upload'
 # Copyright (C) 2018 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -23,8 +24,8 @@ import ovirtsdk4.types as types
 import sys
 import time
 
-from http.client import HTTPSConnection
-from urllib.parse import urlparse
+from httplib import HTTPSConnection
+from urlparse import urlparse
 
 # Parameters are passed in via a JSON doc from the OCaml code.
 # Because this Python code ships embedded inside virt-v2v there
@@ -35,8 +36,19 @@ if len(sys.argv) != 2:
     raise RuntimeError("incorrect number of parameters")
 
 # Parameters are passed in via a JSON document.
+# https://stackoverflow.com/a/13105359
+def byteify(input):
+    if isinstance(input, dict):
+        return {byteify(key): byteify(value)
+                for key, value in input.iteritems()}
+    elif isinstance(input, list):
+        return [byteify(element) for element in input]
+    elif isinstance(input, unicode):
+        return input.encode('utf-8')
+    else:
+        return input
 with open(sys.argv[1], 'r') as fp:
-    params = json.load(fp)
+    params = byteify(json.load(fp))
 
 # What is passed in is a password file, read the actual password.
 with open(params['output_password'], 'r') as fp:
@@ -66,7 +78,7 @@ vms = vms_service.list(
 )
 if len(vms) > 0:
     vm = vms[0]
-    raise RuntimeError("VM already exists with name ‘%s’, id ‘%s’" %
+    raise RuntimeError("VM already exists with name '%s', id
'%s'" %
                        (params['output_name'], vm.id))
 
 # Otherwise everything is OK, exit with no error.
-- 
1.8.3.1