software/kvm: Switch to python3 only

There is no reason to keep python2 compatibility, as python3 flavour of the
KVM software release is good enough.

software/kvm/software-py3.cfg

-[buildout]
-extends =
-  software.cfg
-
-[python]
-part = python3

software/kvm/software.cfg

@@ -40,6 +40,9 @@ parts = ${:common-parts}
 
 #XXX-Cedric : add list of keyboard layouts (azerty/us querty/...) parameter to qemu
 
+[python]
+part = python3
+
 [python-with-eggs]
 recipe = zc.recipe.egg
 interpreter = ${:_buildout_section_name_}

software/kvm/test/test.py

@@ -60,8 +60,7 @@ skipUnlessKvm = unittest.skipUnless(has_kvm, 'kvm not loaded or not allowed')
 if has_kvm:
   setUpModule, InstanceTestCase = makeModuleSetUpAndTestCaseClass(
     os.path.abspath(
-      os.path.join(os.path.dirname(__file__), '..',
-                   'software%s.cfg' % ("-py3" if six.PY3 else ""))))
+      os.path.join(os.path.dirname(__file__), '..', 'software.cfg')))
   # XXX Keep using slapos node instance --all, because of missing promises
   InstanceTestCase.slap._force_slapos_node_instance_all = True
 else:
@@ -1792,14 +1791,17 @@ class TestExternalDisk(InstanceTestCase, KvmMixin):
         'w') as fh:
         json.dump(slapos_resource, fh, indent=2)
     # above is not enough: the presence of parameter is required in slapos.cfg
+    slapos_config = []
     with open(cls.slap._slapos_config) as fh:
-      slapos_config = fh.read()
-    slapos_config += '\n' + """
-[slapos]
-instance_storage_home = %s
-""" % (external_storage_path,)
+      for line in fh.readlines():
+        if line.strip() == '[slapos]':
+          slapos_config.append('[slapos]\n')
+          slapos_config.append(
+            'instance_storage_home = %s\n' % (external_storage_path,))
+        else:
+          slapos_config.append(line)
     with open(cls.slap._slapos_config, 'w') as fh:
-      fh.write(slapos_config)
+      fh.write(''.join(slapos_config))
 
   @classmethod
   def _setUpClass(cls):

software/slapos-sr-testing/software-py3.cfg

@@ -19,6 +19,7 @@ extra =
   helloworld ${slapos.test.helloworld-setup:setup}
   hugo ${slapos.test.hugo-setup:setup}
   jupyter ${slapos.test.jupyter-setup:setup}
+  kvm ${slapos.test.kvm-setup:setup}
   matomo ${slapos.test.matomo-setup:setup}
   monitor ${slapos.test.monitor-setup:setup}
   nextcloud ${slapos.test.nextcloud-setup:setup}

software/slapos-sr-testing/software.cfg

@@ -350,7 +350,6 @@ tests =
 # here, to check there's no promise issue when slapos node runs with Python 2.
   erp5 ${slapos.test.erp5-setup:setup}
   fluentd ${slapos.test.fluentd-setup:setup}
-  kvm ${slapos.test.kvm-setup:setup}
   metabase ${slapos.test.metabase-setup:setup}
 ###
   ${:extra}