summaryrefslogtreecommitdiffstats
path: root/vnftest/core/task.py
blob: 7cdd8655ca7fcb1242f31a82845185533f85f926 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
##############################################################################
# Copyright 2018 EuropeanSoftwareMarketingLtd.
# ===================================================================
#  Licensed under the ApacheLicense, Version2.0 (the"License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#  http://www.apache.org/licenses/LICENSE-2.0
#
# software distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under
# the License
##############################################################################
# vnftest comment: this is a modified copy of
# yardstick/benchmark/core/task.py

""" Handler for vnftest command 'task' """

from __future__ import absolute_import
from __future__ import print_function

import atexit
import collections
import copy
import logging
import sys
import time
import traceback
import uuid

import ipaddress
import os
import yaml
from jinja2 import Environment
from six.moves import filter

from vnftest.runners import base as base_runner

from vnftest.contexts.base import Context
from vnftest.runners import base as base_runner
from vnftest.runners.duration import DurationRunner
from vnftest.runners.iteration import IterationRunner
from vnftest.common.constants import CONF_FILE
from vnftest.common.html_template import report_template
from vnftest.common.task_template import TaskTemplate
from vnftest.common.yaml_loader import yaml_load
from vnftest.contexts.base import Context
from vnftest.dispatcher.base import Base as DispatcherBase
from vnftest.common.task_template import TaskTemplate
from vnftest.common import utils
from vnftest.common import constants
from vnftest.common.html_template import report_template

output_file_default = "/tmp/vnftest.out"
LOG = logging.getLogger(__name__)


class Task(object):     # pragma: no cover
    """Task commands.

       Set of commands to manage benchmark tasks.
    """

    def __init__(self, args):
        self.contexts = None
        self.outputs = {}
        self.args = args or {}
        task_id = getattr(args, 'task_id', None)
        self.task_id = task_id if task_id is not None else str(uuid.uuid4())
        self.task_info = TaskInfo(task_id)

    def _set_dispatchers(self, output_config):
        dispatchers = output_config.get('DEFAULT', {}).get('dispatcher',
                                                           'file')
        out_types = [s.strip() for s in dispatchers.split(',')]
        output_config['DEFAULT']['dispatcher'] = out_types

    def start(self):
        atexit.register(self.atexit_handler)
        self._set_log()
        try:
            output_config = utils.parse_ini_file(CONF_FILE)
        except Exception:
            # all error will be ignore, the default value is {}
            output_config = {}

        self._init_output_config(output_config)
        self._set_output_config(output_config, self.args.output_file)
        LOG.debug('Output configuration is: %s', output_config)

        self._set_dispatchers(output_config)

        # update dispatcher list
        if 'file' in output_config['DEFAULT']['dispatcher']:
            result = {'status': 0, 'result': {}}
            utils.write_json_to_file(self.args.output_file, result)

        total_start_time = time.time()
        parser = TaskParser(self.args.inputfile)

        if self.args.suite:
            # 1.parse suite, return suite_params info
            task_files, task_args_list, task_args_fnames = parser.parse_suite()

        else:
            task_files = [parser.path]
            task_args_list = [{}]
            task_args_fnames = [self.args.task_args_file]

        LOG.debug("task_files:%s, task_args_list:%s, task_args_fnames:%s",
                  task_files, task_args_list, task_args_fnames)

        if self.args.parse_only:
            sys.exit(0)

        try:
            for i in range(0, len(task_files)):
                one_task_start_time = time.time()
                # the output of the previous task is the input of the new task
                inputs = copy.deepcopy(self.outputs)
                task_args_file = task_args_fnames[i]
                task_args = task_args_list[i]
                try:
                    inputs.update(parse_task_args("global_task_args", self.args.task_args))
                    if task_args_file:
                        with utils.load_resource(task_args_file) as f:
                            inputs.update(parse_task_args("task_args_file", f.read()))
                    # task args from suite may override file args.
                    inputs.update(parse_task_args("task_args", task_args))
                except TypeError:
                    raise TypeError()
                parser.path = task_files[i]
                steps, run_in_parallel, meet_precondition, ret_contexts = \
                    parser.parse_task(self.task_id, inputs)

                self.contexts = ret_contexts

                if not meet_precondition:
                    LOG.info("meet_precondition is %s, please check envrionment",
                             meet_precondition)
                    continue

                case_name = os.path.splitext(os.path.basename(task_files[i]))[0]
                try:
                    self._run(steps, case_name, run_in_parallel, self.args.output_file, inputs)
                except KeyboardInterrupt:
                    raise
                except Exception:
                    LOG.error('Testcase: "%s" FAILED!!!', case_name, exc_info=True)

                if self.args.keep_deploy:
                    # keep deployment, forget about stack
                    # (hide it for exit handler)
                    self.contexts = None
                else:
                    if self.contexts is not None:
                        for context in self.contexts:
                            context.undeploy()
                        self.contexts = None
                one_task_end_time = time.time()
                LOG.info("Task %s finished in %d secs", task_files[i],
                         one_task_end_time - one_task_start_time)
        except Exception as e:
            LOG.error("Task fatal error: %s", e)
            traceback.print_exc()
            self.task_info.task_fatal()
        finally:
            self.task_info.task_end()

        self._do_output(output_config)
        self._generate_reporting()

        total_end_time = time.time()
        LOG.info("Total finished in %d secs",
                 total_end_time - total_start_time)
        return self.task_info.result()

    def _generate_reporting(self):
        env = Environment()
        file_name = 'report_' + str(self.task_id) + '.html'
        report_file = os.path.join(constants.REPORT_DIR, file_name)
        with open(report_file, 'w') as f:
            f.write(env.from_string(report_template).render(self.task_info.result()))

        LOG.info("Report can be found in '%s'", report_file)

    def _set_log(self):
        log_format = '%(asctime)s %(name)s %(filename)s:%(lineno)d %(levelname)s %(message)s'
        log_formatter = logging.Formatter(log_format)

        utils.makedirs(constants.TASK_LOG_DIR)
        log_path = os.path.join(constants.TASK_LOG_DIR, '{}.log'.format(self.task_id))
        log_handler = logging.FileHandler(log_path)
        log_handler.setFormatter(log_formatter)
        log_handler.setLevel(logging.DEBUG)

        logging.root.addHandler(log_handler)

    def _init_output_config(self, output_config):
        output_config.setdefault('DEFAULT', {})
        output_config.setdefault('dispatcher_http', {})
        output_config.setdefault('dispatcher_file', {})
        output_config.setdefault('dispatcher_influxdb', {})

    def _set_output_config(self, output_config, file_path):
        try:
            out_type = os.environ['DISPATCHER']
        except KeyError:
            output_config['DEFAULT'].setdefault('dispatcher', 'file')
        else:
            output_config['DEFAULT']['dispatcher'] = out_type

        output_config['dispatcher_file']['file_path'] = file_path

        try:
            target = os.environ['TARGET']
        except KeyError:
            pass
        else:
            k = 'dispatcher_{}'.format(output_config['DEFAULT']['dispatcher'])
            output_config[k]['target'] = target

    def _do_output(self, output_config):
        dispatchers = DispatcherBase.get(output_config)

        for dispatcher in dispatchers:
            dispatcher.flush_result_data(self.task_id, self.task_info.result())

    def _run(self, steps, case_name, run_in_parallel, output_file, inputs):
        try:
            self.task_info.testcase_start(case_name)
            for step in steps:
                step_unique_id = self.task_info.step_add(case_name, step['name'])
                step['step_unique_id'] = step_unique_id

            """Deploys context and calls runners"""
            if self.contexts is not None:
                for context in self.contexts:
                    output = None
                    try:
                        self.task_info.context_deploy_start(case_name, context.assigned_name)
                        output = context.deploy()
                    finally:
                        self.task_info.context_deploy_end(case_name, context.assigned_name, output)

            background_runners = []
            result = []
            # Start all background steps
            for step in filter(_is_background_step, steps):
                step["runner"] = dict(type="Duration", duration=1000000000)
                self.task_info.step_start(step['step_unique_id'])
                runner = self.run_one_step(step, output_file, inputs)
                background_runners.append([step, runner])

            runners = []
            if run_in_parallel:
                for step in steps:
                    if not _is_background_step(step):
                        self.task_info.step_start(step['step_unique_id'])
                        runner = self.run_one_step(step, output_file, inputs)
                        runners.append([step, runner])

                # Wait for runners to finish
                for runner_item in runners:
                    self.finalize_step(runner_item[0], runner_item[1], result)
            else:
                # run serially
                for step in steps:
                    if not _is_background_step(step):
                        self.task_info.step_start(step['step_unique_id'])
                        runner = self.run_one_step(step, output_file, inputs)
                        self.finalize_step(step, runner, result)

            # Abort background runners
            for runner_item in background_runners:
                runner_item[1].abort()

            # Wait for background runners to finish
            for runner_item in background_runners:
                runner = runner_item[1]
                self.finalize_step(step, runner, result)
            return result
        except Exception as e:
            LOG.exception('Case fatal error: %s', e)
            traceback.print_exc()
            self.task_info.testcase_fatal(case_name)
        finally:
            self.task_info.testcase_end(case_name)

    def atexit_handler(self):
        """handler for process termination"""
        base_runner.Runner.terminate_all()

        if self.contexts:
            LOG.info("Undeploying context")
            for context in self.contexts:
                context.undeploy()

    def _parse_options(self, op):
        if isinstance(op, dict):
            return {k: self._parse_options(v) for k, v in op.items()}
        elif isinstance(op, list):
            return [self._parse_options(v) for v in op]
        elif isinstance(op, str):
            return self.outputs.get(op[1:]) if op.startswith('$') else op
        else:
            return op

    def run_one_step(self, step_cfg, output_file, inputs):
        """run one step using context"""
        # default runner is Iteration
        if 'runner' not in step_cfg:
            step_cfg['runner'] = dict(type="Iteration", iterations=1)
        runner_cfg = step_cfg['runner']
        runner_cfg['output_filename'] = output_file
        options = step_cfg.get('options', {})
        step_cfg['options'] = self._parse_options(options)
        runner = base_runner.Runner.get(runner_cfg)

        LOG.info("Starting runner of type '%s'", runner_cfg["type"])
        # Previous steps output is the input of the next step.
        inputs.update(self.outputs)
        _resolve_step_options(step_cfg, self.contexts, inputs)
        runner.run(step_cfg, self.contexts, inputs)
        return runner

    def finalize_step(self, step, runner, result):
        step_result_list = []
        status = runner_join(runner, self.outputs, step_result_list)
        self.task_info.step_end(step['step_unique_id'], step_result_list)
        if status != 0:
            raise RuntimeError(
                "{0} runner status {1}".format(runner.__execution_type__, status))
        LOG.info("Runner ended")
        result.extend(step_result_list)


def _resolve_step_options(step_cfg, contexts, inputs):
    inputs = copy.deepcopy(inputs)
    contexts_dict = {}
    inputs['context'] = contexts_dict
    if contexts is not None:
        for context in contexts:
            context_as_dict = utils.normalize_data_struct(context)
            contexts_dict[context.assigned_name] = context_as_dict
    options = step_cfg.get("options", {})
    resolved_options = {}
    for k, v in options.items():
        v = utils.format(v, inputs)
        resolved_options[k] = v
    step_cfg["options"] = resolved_options


class TaskParser(object):       # pragma: no cover
    """Parser for task config files in yaml format"""

    def __init__(self, path):
        self.path = path

    def _meet_constraint(self, task, cur_pod, cur_installer):
        if "constraint" in task:
            constraint = task.get('constraint', None)
            if constraint is not None:
                tc_fit_pod = constraint.get('pod', None)
                tc_fit_installer = constraint.get('installer', None)
                LOG.info("cur_pod:%s, cur_installer:%s,tc_constraints:%s",
                         cur_pod, cur_installer, constraint)
                if (cur_pod is None) or (tc_fit_pod and cur_pod not in tc_fit_pod):
                    return False
                if (cur_installer is None) or (tc_fit_installer and cur_installer
                                               not in tc_fit_installer):
                    return False
        return True

    def _get_task_para(self, task, cur_pod):
        task_args = task.get('task_args', None)
        if task_args is not None:
            task_args = task_args.get(cur_pod, task_args.get('default'))
        task_args_fnames = task.get('task_args_fnames', None)
        if task_args_fnames is not None:
            task_args_fnames = task_args_fnames.get(cur_pod, None)
        return task_args, task_args_fnames

    def parse_suite(self):
        """parse the suite file and return a list of task config file paths
           and lists of optional parameters if present"""
        LOG.info("\nParsing suite file:%s", self.path)

        try:
            with utils.load_resource(self.path) as stream:
                cfg = yaml_load(stream)
        except IOError as ioerror:
            LOG.error("Open suite file failed", ioerror)
            raise

        self._check_schema(cfg["schema"], "suite")
        LOG.info("\nStarting step:%s", cfg["name"])

        cur_pod = os.environ.get('NODE_NAME', "default")
        cur_installer = os.environ.get('INSTALLER_TYPE', None)

        valid_task_files = []
        valid_task_args = []
        valid_task_args_fnames = []

        for task in cfg["test_cases"]:
            # 1.check file_name
            if "file_name" in task:
                task_fname = task.get('file_name', None)
                if task_fname is None:
                    continue
            else:
                continue
            # 2.check constraint
            if self._meet_constraint(task, cur_pod, cur_installer):
                valid_task_files.append(task_fname)
            else:
                continue
            # 3.fetch task parameters
            task_args, task_args_fnames = self._get_task_para(task, cur_pod)
            valid_task_args.append(task_args)
            valid_task_args_fnames.append(task_args_fnames)

        return valid_task_files, valid_task_args, valid_task_args_fnames

    def parse_task(self, task_id, inputs=None):
        """parses the task file and return an context and step instances"""
        LOG.info("Parsing task config: %s", self.path)
        kw = inputs
        try:
            with utils.load_resource(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)

        self._check_schema(cfg["schema"], "task")
        meet_precondition = self._check_precondition(cfg)

        if "context" in cfg:
            context_cfgs = [cfg["context"]]
        elif "contexts" in cfg:
            context_cfgs = cfg["contexts"]
        else:
            context_cfgs = [{"type": "Dummy", "name": "Dummy"}]

        _contexts = []
        for cfg_attrs in context_cfgs:
            cfg_attrs['task_id'] = task_id
            context_type = cfg_attrs.get("type")
            context = Context.get(context_type)
            context.init(cfg_attrs)
            _contexts.append(context)

        run_in_parallel = cfg.get("run_in_parallel", False)

        # add tc and task id for influxdb extended tags
        for step in cfg["steps"]:
            task_name = os.path.splitext(os.path.basename(self.path))[0]
            step["tc"] = task_name
            step["task_id"] = task_id
            # embed task path into step so we can load other files
            # relative to task path
            step["task_path"] = os.path.dirname(self.path)

        # TODO we need something better here, a class that represent the file
        return cfg["steps"], run_in_parallel, meet_precondition, _contexts

    def _check_schema(self, cfg_schema, schema_type):
        """Check if config file is using the correct schema type"""

        if cfg_schema != "vnftest:" + schema_type + ":0.1":
            sys.exit("error: file %s has unknown schema %s" % (self.path,
                                                               cfg_schema))

    def _check_precondition(self, cfg):
        """Check if the environment meet the precondition"""

        if "precondition" in cfg:
            precondition = cfg["precondition"]
            installer_type = precondition.get("installer_type", None)
            tc_fit_pods = precondition.get("pod_name", None)
            installer_type_env = os.environ.get('INSTALL_TYPE', None)
            pod_name_env = os.environ.get('NODE_NAME', None)

            LOG.info("installer_type: %s, installer_type_env: %s",
                     installer_type, installer_type_env)
            LOG.info("tc_fit_pods: %s, pod_name_env: %s",
                     tc_fit_pods, pod_name_env)
            if installer_type and installer_type_env:
                if installer_type_env not in installer_type:
                    return False
                return False
            if tc_fit_pods and pod_name_env:
                if pod_name_env not in tc_fit_pods:
                    return False
        return True


class TaskInfo(object):

    def __init__(self, task_id):
        self.info_dict = {'task_id': task_id, 'status': 'IN_PROGRESS', 'criteria': 'N/A'}
        self.result_info_dict = {}
        self.info_dict['info'] = self.result_info_dict
        self.test_cases_list = []
        self.info_dict['testcases'] = self.test_cases_list
        self.helper_test_cases_dict = {}
        self.helper_test_steps_dict = {}
        self.helper_contexts_dict = {}
        self.step_id_helper = 0

    def task_end(self):
        if self.info_dict['criteria'] == 'N/A':
            criteria = 'PASS'
            for testcase in self.info_dict['testcases']:
                if testcase['criteria'] == 'FAIL' or testcase['criteria'] == 'FATAL':
                    criteria = 'FAIL'
                    break
            self.info_dict['criteria'] = criteria
            self.info_dict['status'] = 'FINISHED'

    def task_fatal(self):
        self.info_dict['criteria'] = 'FATAL'
        self.info_dict['status'] = 'FINISHED'

    def testcase_fatal(self, testcase_name):
        testcase_dict = self.helper_test_cases_dict[testcase_name]
        testcase_dict['criteria'] = 'FATAL'
        testcase_dict['status'] = 'FINISHED'

    def testcase_start(self, testcase_name):
        testcase_dict = {'name': testcase_name, 'criteria': 'N/A', 'status': 'IN_PROGRESS', 'steps': [], 'contexts': []}
        self.test_cases_list.append(testcase_dict)
        self.helper_test_cases_dict[testcase_name] = testcase_dict

    def testcase_end(self, testcase_name):
        testcase_dict = self.helper_test_cases_dict[testcase_name]
        if testcase_dict['criteria'] == 'N/A':
            criteria = 'PASS'
            for step in testcase_dict['steps']:
                if step['criteria'] == 'FAIL':
                    criteria = 'FAIL'
                    break
            testcase_dict['criteria'] = criteria
            testcase_dict['status'] = 'FINISHED'

    def step_add(self, testcase_name, step_name):
        step_dict = {'name': step_name, 'criteria': 'N/A', 'status': 'NOT_STARTED', 'results': []}
        testcase_dict = self.helper_test_cases_dict[testcase_name]
        testcase_dict['steps'].append(step_dict)
        self.step_id_helper += 1
        step_unique_id = step_name + '_' + str(self.step_id_helper)
        self.helper_test_steps_dict[step_unique_id] = step_dict
        return step_unique_id

    def step_start(self, step_unique_id):
        step_dict = self.helper_test_steps_dict[step_unique_id]
        step_dict['status'] = 'IN_PROGRESS'

    def step_end(self, step_unique_id, result_list):
        step_dict = self.helper_test_steps_dict[step_unique_id]
        errors_count = 0
        for result in result_list:
            result_item = {
                'timestamp': result['timestamp'],
                'sequence': result['sequence'],
                'data': [],
                'errors': []
            }
            for k, v in result['data'].items():
                result_item['data'].append({'type': 'String', 'key': k, 'value': str(v)})

            for error in result['errors']:
                result_item['errors'].append({'type': 'String', 'key': 'error', 'value': str(error)})
                errors_count += 1
            step_dict['results'].append(result_item)
        if errors_count > 0:
            step_dict['criteria'] = 'FAIL'
        else:
            step_dict['criteria'] = 'PASS'
        step_dict['status'] = 'FINISHED'

    def context_deploy_start(self, testcase_name, context_name):
        context_dict = {'name': context_name, 'status': 'IN_PROGRESS', 'output': []}
        testcase_dict = self.helper_test_cases_dict[testcase_name]
        testcase_dict['contexts'].append(context_dict)
        context_unique_id = testcase_name + '_' + context_name
        self.helper_contexts_dict[context_unique_id] = context_dict

    def context_deploy_end(self, testcase_name, context_name, output):
        context_unique_id = testcase_name + '_' + context_name
        context_dict = self.helper_contexts_dict[context_unique_id]
        if output is not None:
            for k, v in output.items():
                context_dict['output'].append({'type': 'String', 'key': k, 'value': str(v)})
        context_dict['status'] = 'FINISHED'

    def result(self):
        return copy.deepcopy(self.info_dict)


def is_ip_addr(addr):
    """check if string addr is an IP address"""
    try:
        addr = addr.get('public_ip_attr', addr.get('private_ip_attr'))
    except AttributeError:
        pass

    try:
        ipaddress.ip_address(addr.encode('utf-8'))
    except ValueError:
        return False
    else:
        return True


def _is_background_step(step):
    if "run_in_background" in step:
        return step["run_in_background"]
    else:
        return False


def runner_join(runner, outputs, result):
    while runner.poll() is None:
        outputs.update(runner.get_output())
        result.extend(runner.get_result())
    status = runner.join(outputs, result)
    base_runner.Runner.release(runner)
    return status


def print_invalid_header(source_name, args):
    print("Invalid %(source)s passed:\n\n %(args)s\n"
          % {"source": source_name, "args": args})


def parse_task_args(src_name, args):
    if isinstance(args, collections.Mapping):
        return args

    try:
        kw = args and yaml_load(args)
        kw = {} if kw is None else kw
    except yaml.parser.ParserError as e:
        print_invalid_header(src_name, args)
        print("%(source)s has to be YAML. Details:\n\n%(err)s\n"
              % {"source": src_name, "err": e})
        raise TypeError()

    if not isinstance(kw, dict):
        print_invalid_header(src_name, args)
        print("%(src)s had to be dict, actually %(src_type)s\n"
              % {"src": src_name, "src_type": type(kw)})
        raise TypeError()
    return kw