Execute undercloud preflight validations via VF binary

Execute undercloud preflight validations via the Validation Framework
binary instead of via the VF API avoid breakage when an API change is introduce.
Its also fix some issues present in the previous implementation:
- the validations was logged in /tmp instead of the /var/log/validations,
  so the logs wasn't shown in the CLI history command.
- the results of the executed validations was never checked, so when the
  validations was failing, the undercloud install can still continue

Change-Id: I149932625fe474175e3842fa52adfea30021ab5c

tripleoclient/v1/undercloud_preflight.py

@@ -30,8 +30,6 @@ from oslo_config import cfg
 from tripleoclient import constants
 from tripleoclient import utils
 
-from validations_libs.validation_actions import ValidationActions
-
 
 class FailedValidation(Exception):
     pass
@@ -63,7 +61,7 @@ def _run_live_command(args, env=None, name=None, cwd=None, wait=True):
         return process
 
     while True:
-        line = process.stdout.readline().decode('utf-8')
+        line = process.stdout.readline()
         if line:
             LOG.info(line.rstrip())
         if line == '' and process.poll() is not None:
@@ -91,12 +89,9 @@ def _run_validations(upgrade=False):
     else:
         playbook_args = constants.DEPLOY_ANSIBLE_ACTIONS['preflight-deploy']
 
-    with utils.TempDirs() as tmp:
-        actions = ValidationActions(log_path=tmp)
-        actions.run_validations(
-            inventory='undercloud',
-            validations_dir=constants.ANSIBLE_VALIDATION_DIR,
-            validation_name=playbook_args['playbooks'])
+    args = ['validation', 'run', '-i', 'undercloud', '--validation',
+            ','.join(playbook_args['playbooks'])]
+    _run_live_command(args)
 
 
 def _check_memory():