Provide option to only validate template

The heat-translator users may only want to validate template without an actual
translation. Create a new optional arg that will only validate template
without running translation.

Change-Id: Ibd17042b365c4c24940e693b87f908a38c681391
Partially Implements: blueprint template-validation-only

translator/shell.py

@@ -21,7 +21,7 @@ from toscaparser.utils.urlutils import UrlUtils
 from translator.hot.tosca_translator import TOSCATranslator
 
 """
-Test the heat-translator from command line as:
+Test the heat-translator translation from command line as:
 #heat-translator
   --template-file=<path to the YAML template>
   --template-type=<type of template e.g. tosca>
@@ -31,7 +31,10 @@ Takes three user arguments,
 2. Path to the file that needs to be translated (required)
 3. Input parameters (optional)
 
-This is an entry point for testing purpose on CLI.
+In order to use heat-translator to only validate template,
+without actual translation, pass --validate-only=true along with
+other required arguments.
+
 """
 
 log = logging.getLogger("heat-translator")
@@ -68,16 +71,31 @@ class TranslatorShell(object):
             raise ValueError(_("%(value)s is not a valid template type.")
                              % {'value': template_type})
         parsed_params = {}
+        validate_only = None
         if len(args) > 2:
-            parsed_params = self._parse_parameters(args[2])
-
+            parameters = None
+            for arg in args:
+                if "--validate-only=" in arg:
+                    validate_only = arg
+                if "--parameters=" in arg:
+                    parameters = arg
+            if parameters:
+                parsed_params = self._parse_parameters(parameters)
         a_file = os.path.isfile(path)
         a_url = UrlUtils.validate_url(path) if not a_file else False
         if a_file or a_url:
-            heat_tpl = self._translate(template_type, path, parsed_params,
-                                       a_file)
-            if heat_tpl:
-                self._write_output(heat_tpl)
+            run_only_validation = False
+            if validate_only:
+                value = validate_only.split('-validate-only=')[1].lower()
+                if template_type == 'tosca' and value == 'true':
+                    run_only_validation = True
+            if run_only_validation:
+                ToscaTemplate(path, parsed_params, a_file)
+            else:
+                heat_tpl = self._translate(template_type, path, parsed_params,
+                                           a_file)
+                if heat_tpl:
+                    self._write_output(heat_tpl)
         else:
             raise ValueError(_("The path %(path)s is not a valid file"
                                " or URL.") % {'path': path})

translator/tests/data/tosca_helloworld_invalid.yaml

@@ -0,0 +1,23 @@
+tosca_definitions: tosca_simple_yaml_1_0
+
+description: Template with invalid version and topology_template section.
+
+topology_template:
+  node_temp:
+    my_server:
+      type: tosca.nodes.Compute
+      capabilities:
+        # Host container properties
+        host:
+         properties:
+           num_cpus: 2
+           disk_size: 10 GB
+           mem_size: 512 MB
+        # Guest Operating System properties
+        os:
+          properties:
+            # host Operating System image properties
+            architecture: x86_64
+            type: Linux
+            distribution: RHEL
+            version: 6.5

translator/tests/test_shell.py

@@ -12,6 +12,7 @@
 
 import os
 
+from toscaparser.common import exception
 from toscaparser.utils.gettextutils import _
 import translator.shell as shell
 from translator.tests.base import TestCase
@@ -23,6 +24,7 @@ class ShellTest(TestCase):
         "data/tosca_helloworld.yaml")
     template_file = '--template-file=' + tosca_helloworld
     template_type = '--template-type=tosca'
+    template_validation = "--validate-only=true"
 
     def test_missing_arg(self):
         error = self.assertRaises(ValueError, shell.main, '')
@@ -80,3 +82,18 @@ class ShellTest(TestCase):
             shell.main([template, self.template_type, parameters])
         except Exception:
             self.fail(_('The program raised an exception unexpectedly.'))
+
+    def test_validate_only(self):
+        try:
+            shell.main([self.template_file, self.template_type,
+                        self.template_validation])
+        except Exception:
+            self.fail(_('The program raised an exception unexpectedly.'))
+
+        template = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data/tosca_helloworld_invalid.yaml")
+        invalid_template = '--template-file=' + template
+        self.assertRaises(exception.ValidationError, shell.main,
+                          [invalid_template, self.template_type,
+                           self.template_validation])