Add "render-only" option to "task" command

This new option provides to the user the ability to output the rendered
input files. This option could be useful in case the input files are
Jinja2 templates, depending on input arguments. The user can preview
the rendered input tasks files without executing them.

JIRA: YARDSTICK-1020

Change-Id: Ib15ade7e1adcb29beae5e635fb5d02045c4432bb
Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>

1 files changed, 82 insertions, 47 deletions

diff --git a/yardstick/benchmark/core/task.py b/yardstick/benchmark/core/task.py
index 4993d2a7e..ba6c9c830 100644
--- a/yardstick/benchmark/core/task.py
+++ b/yardstick/benchmark/core/task.py
@@ -7,7 +7,6 @@
 # http://www.apache.org/licenses/LICENSE-2.0
 ##############################################################################
 
-
 import sys
 import os
 from collections import OrderedDict
@@ -28,10 +27,10 @@ from yardstick.benchmark.runners import base as base_runner
 from yardstick.common.constants import CONF_FILE
 from yardstick.common.yaml_loader import yaml_load
 from yardstick.dispatcher.base import Base as DispatcherBase
-from yardstick.common.task_template import TaskTemplate
-from yardstick.common import utils
 from yardstick.common import constants
-from yardstick.common import exceptions
+from yardstick.common import exceptions as y_exc
+from yardstick.common import task_template
+from yardstick.common import utils
 from yardstick.common.html_template import report_template
 
 output_file_default = "/tmp/yardstick.out"
@@ -55,7 +54,7 @@ class Task(object):     # pragma: no cover
         out_types = [s.strip() for s in dispatchers.split(',')]
         output_config['DEFAULT']['dispatcher'] = out_types
 
-    def start(self, args):
+    def start(self, args, **kwargs):  # pylint: disable=unused-argument
         """Start a benchmark scenario."""
 
         atexit.register(self.atexit_handler)
@@ -87,8 +86,7 @@ class Task(object):     # pragma: no cover
 
         if args.suite:
             # 1.parse suite, return suite_params info
-            task_files, task_args, task_args_fnames = \
-                parser.parse_suite()
+            task_files, task_args, task_args_fnames = parser.parse_suite()
         else:
             task_files = [parser.path]
             task_args = [args.task_args]
@@ -101,32 +99,33 @@ class Task(object):     # pragma: no cover
             sys.exit(0)
 
         testcases = {}
-        # parse task_files
-        for i in range(0, len(task_files)):
-            one_task_start_time = time.time()
-            parser.path = task_files[i]
-            scenarios, run_in_parallel, meet_precondition, contexts = \
-                parser.parse_task(self.task_id, task_args[i],
-                                  task_args_fnames[i])
-
-            self.contexts.extend(contexts)
+        tasks = self._parse_tasks(parser, task_files, args, task_args,
+                                  task_args_fnames)
 
-            if not meet_precondition:
-                LOG.info("meet_precondition is %s, please check envrionment",
-                         meet_precondition)
+        # Execute task files.
+        for i, _ in enumerate(task_files):
+            one_task_start_time = time.time()
+            self.contexts.extend(tasks[i]['contexts'])
+            if not tasks[i]['meet_precondition']:
+                LOG.info('"meet_precondition" is %s, please check environment',
+                         tasks[i]['meet_precondition'])
                 continue
 
-            case_name = os.path.splitext(os.path.basename(task_files[i]))[0]
             try:
-                data = self._run(scenarios, run_in_parallel, output_config)
+                data = self._run(tasks[i]['scenarios'],
+                                 tasks[i]['run_in_parallel'],
+                                 output_config)
             except KeyboardInterrupt:
                 raise
             except Exception:  # pylint: disable=broad-except
-                LOG.error('Testcase: "%s" FAILED!!!', case_name, exc_info=True)
-                testcases[case_name] = {'criteria': 'FAIL', 'tc_data': []}
+                LOG.error('Testcase: "%s" FAILED!!!', tasks[i]['case_name'],
+                          exc_info=True)
+                testcases[tasks[i]['case_name']] = {'criteria': 'FAIL',
+                                                    'tc_data': []}
             else:
-                LOG.info('Testcase: "%s" SUCCESS!!!', case_name)
-                testcases[case_name] = {'criteria': 'PASS', 'tc_data': data}
+                LOG.info('Testcase: "%s" SUCCESS!!!', tasks[i]['case_name'])
+                testcases[tasks[i]['case_name']] = {'criteria': 'PASS',
+                                                    'tc_data': data}
 
             if args.keep_deploy:
                 # keep deployment, forget about stack
@@ -149,9 +148,8 @@ class Task(object):     # pragma: no cover
         LOG.info("Total finished in %d secs",
                  total_end_time - total_start_time)
 
-        scenario = scenarios[0]
-        LOG.info("To generate report, execute command "
-                 "'yardstick report generate %(task_id)s %(tc)s'", scenario)
+        LOG.info('To generate report, execute command "yardstick report '
+                 'generate %(task_id)s <yaml_name>s"', self.task_id)
         LOG.info("Task ALL DONE, exiting")
         return result
 
@@ -312,6 +310,30 @@ class Task(object):     # pragma: no cover
         else:
             return op
 
+    def _parse_tasks(self, parser, task_files, args, task_args,
+                     task_args_fnames):
+        tasks = []
+
+        # Parse task_files.
+        for i, _ in enumerate(task_files):
+            parser.path = task_files[i]
+            tasks.append(parser.parse_task(self.task_id, task_args[i],
+                                           task_args_fnames[i]))
+            tasks[i]['case_name'] = os.path.splitext(
+                os.path.basename(task_files[i]))[0]
+
+        if args.render_only:
+            utils.makedirs(args.render_only)
+            for idx, task in enumerate(tasks):
+                output_file_name = os.path.abspath(os.path.join(
+                    args.render_only,
+                    '{0:03d}-{1}.yml'.format(idx, task['case_name'])))
+                utils.write_file(output_file_name, task['rendered'])
+
+            sys.exit(0)
+
+        return tasks
+
     def run_one_scenario(self, scenario_cfg, output_config):
         """run one scenario using context"""
         runner_cfg = scenario_cfg["runner"]
@@ -477,33 +499,42 @@ class TaskParser(object):       # pragma: no cover
 
         return valid_task_files, valid_task_args, valid_task_args_fnames
 
-    def parse_task(self, task_id, task_args=None, task_args_file=None):
-        """parses the task file and return an context and scenario instances"""
-        LOG.info("Parsing task config: %s", self.path)
+    def _render_task(self, task_args, task_args_file):
+        """Render the input task with the given arguments
 
+        :param task_args: (dict) arguments to render the task
+        :param task_args_file: (str) file containing the arguments to render
+                               the task
+        :return: (str) task file rendered
+        """
         try:
             kw = {}
             if task_args_file:
                 with open(task_args_file) as f:
-                    kw.update(parse_task_args("task_args_file", f.read()))
-            kw.update(parse_task_args("task_args", task_args))
+                    kw.update(parse_task_args('task_args_file', f.read()))
+            kw.update(parse_task_args('task_args', task_args))
         except TypeError:
-            raise TypeError()
+            raise y_exc.TaskRenderArgumentError()
 
+        input_task = None
         try:
             with open(self.path) as f:
-                try:
-                    input_task = f.read()
-                    rendered_task = TaskTemplate.render(input_task, **kw)
-                except Exception as e:
-                    LOG.exception('Failed to render template:\n%s\n', input_task)
-                    raise e
-                LOG.debug("Input task is:\n%s\n", rendered_task)
-
-                cfg = yaml_load(rendered_task)
-        except IOError as ioerror:
-            sys.exit(ioerror)
+                input_task = f.read()
+            rendered_task = task_template.TaskTemplate.render(input_task, **kw)
+            LOG.debug('Input task is:\n%s', rendered_task)
+            parsed_task = yaml_load(rendered_task)
+        except (IOError, OSError):
+            raise y_exc.TaskReadError(task_file=self.path)
+        except Exception:
+            raise y_exc.TaskRenderError(input_task=input_task)
+
+        return parsed_task, rendered_task
+
+    def parse_task(self, task_id, task_args=None, task_args_file=None):
+        """parses the task file and return an context and scenario instances"""
+        LOG.info("Parsing task config: %s", self.path)
 
+        cfg, rendered = self._render_task(task_args, task_args_file)
         self._check_schema(cfg["schema"], "task")
         meet_precondition = self._check_precondition(cfg)
 
@@ -540,7 +571,11 @@ class TaskParser(object):       # pragma: no cover
             self._change_node_names(scenario, contexts)
 
         # TODO we need something better here, a class that represent the file
-        return cfg["scenarios"], run_in_parallel, meet_precondition, contexts
+        return {'scenarios': cfg['scenarios'],
+                'run_in_parallel': run_in_parallel,
+                'meet_precondition': meet_precondition,
+                'contexts': contexts,
+                'rendered': rendered}
 
     @staticmethod
     def _change_node_names(scenario, contexts):
@@ -581,7 +616,7 @@ class TaskParser(object):       # pragma: no cover
                 ctx = next((context for context in contexts
                        if context.assigned_name == context_name))
             except StopIteration:
-                raise exceptions.ScenarioConfigContextNameNotFound(
+                raise y_exc.ScenarioConfigContextNameNotFound(
                     context_name=context_name)
 
             return '{}.{}'.format(node_name, ctx.name)