Fix return code when failing before launching the stack

Until now when a configuration error was detected early during the
pre-deployment verifications, the command would correctly return before
attempting to create/update the Heat stack, however the return code
would still show as '0', preventing scripts from picking up the
problem.

Change-Id: I8bd16e9753618e4c234440d7a6626e0ce4bd9972
Closes-Bug: #1672790

releasenotes/notes/return-code-on-predeploy-failure-bd62025646e25433.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    `overcloud deploy` correctly returns an error code when failing
+    during the pre-deployment verifications (before the stack is
+    launched) (`bug 1672790
+    <https://bugs.launchpad.net/tripleo/+bug/1672790>`__).

tripleoclient/tests/v1/overcloud_deploy/test_overcloud_deploy.py

@@ -1328,3 +1328,28 @@ class TestDeployOvercloud(fakes.TestDeployOvercloud):
 
         self.cmd.take_action(parsed_args)
         self.assertTrue(self.cmd._predeploy_verify_capabilities.called)
+
+    @mock.patch('tripleoclient.utils.get_overcloud_endpoint', autospec=True)
+    @mock.patch('tripleoclient.utils.write_overcloudrc', autospec=True)
+    @mock.patch('tripleoclient.workflows.deployment.overcloudrc',
+                autospec=True)
+    @mock.patch('tripleoclient.v1.overcloud_deploy.DeployOvercloud.'
+                '_deploy_tripleo_heat_templates_tmpdir', autospec=True)
+    def test_validations_failure_raises_exception(
+            self, mock_deploy_tmpdir,
+            mock_overcloudrc, mock_write_overcloudrc,
+            mock_overcloud_endpoint):
+        clients = self.app.client_manager
+        orchestration_client = clients.orchestration
+        orchestration_client.stacks.get.return_value = mock.Mock()
+        self.cmd._predeploy_verify_capabilities = mock.Mock(
+            return_value=(1, 0))
+
+        arglist = ['--templates']
+        verifylist = [
+            ('templates', '/usr/share/openstack-tripleo-heat-templates/'),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        self.assertRaises(exceptions.InvalidConfiguration,
+                          self.cmd.take_action, parsed_args)

tripleoclient/v1/overcloud_deploy.py

@@ -1097,14 +1097,14 @@ class DeployOvercloud(command.Command):
                     errors)
                 if parsed_args.validation_warnings_fatal or \
                         parsed_args.validation_errors_fatal:
-                    return
+                    raise exceptions.InvalidConfiguration()
             if warnings > 0:
                 self.log.error(
                     "Configuration has %d warnings, fix them before "
                     "proceeding.",
                     warnings)
                 if parsed_args.validation_warnings_fatal:
-                    return
+                    raise exceptions.InvalidConfiguration()
             else:
                 self.log.info("SUCCESS: No warnings or errors in deploy "
                               "configuration, proceeding.")