Source code for swh.journal.pytest_plugin

# Copyright (C) 2019-2020 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

from collections import defaultdict
import random
import string
from typing import Collection, Dict, Iterator, Optional

import attr
from confluent_kafka import Consumer, KafkaException, Producer
from confluent_kafka.admin import AdminClient
import pytest

from swh.journal.serializers import kafka_to_key, kafka_to_value, pprint_key
from swh.journal.tests.journal_data import TEST_OBJECTS


[docs]def consume_messages(consumer, kafka_prefix, expected_messages): """Consume expected_messages from the consumer; Sort them all into a consumed_objects dict""" consumed_messages = defaultdict(list) fetched_messages = 0 retries_left = 1000 while fetched_messages < expected_messages: if retries_left == 0: raise ValueError( "Timed out fetching messages from kafka. " f"Only {fetched_messages}/{expected_messages} fetched" ) msg = consumer.poll(timeout=0.01) if not msg: retries_left -= 1 continue error = msg.error() if error is not None: if error.fatal(): raise KafkaException(error) retries_left -= 1 continue fetched_messages += 1 topic = msg.topic() assert topic.startswith(f"{kafka_prefix}.") or topic.startswith( f"{kafka_prefix}_privileged." ), "Unexpected topic" object_type = topic[len(kafka_prefix + ".") :] consumed_messages[object_type].append( (kafka_to_key(msg.key()), kafka_to_value(msg.value())) ) return consumed_messages
[docs]def assert_all_objects_consumed( consumed_messages: Dict, exclude: Optional[Collection] = None ): """Check whether all objects from TEST_OBJECTS have been consumed `exclude` can be a list of object types for which we do not want to compare the values (eg. for anonymized object). """ for object_type, known_objects in TEST_OBJECTS.items(): known_keys = [obj.unique_key() for obj in known_objects] if not consumed_messages[object_type]: return (received_keys, received_values) = zip(*consumed_messages[object_type]) if object_type in ("content", "skipped_content"): for value in received_values: value.pop("ctime", None) if object_type == "content": known_objects = [attr.evolve(o, data=None) for o in known_objects] for key in known_keys: assert key in received_keys, ( f"expected {object_type} key {pprint_key(key)} " "absent from consumed messages" ) if exclude and object_type in exclude: continue for value in known_objects: expected_value = value.to_dict() if value.object_type in ("content", "skipped_content"): expected_value.pop("ctime", None) assert expected_value in received_values, ( f"expected {object_type} value {value!r} is " "absent from consumed messages" )
[docs]@pytest.fixture(scope="function") def kafka_prefix(): """Pick a random prefix for kafka topics on each call""" return "".join(random.choice(string.ascii_lowercase) for _ in range(10))
[docs]@pytest.fixture(scope="function") def kafka_consumer_group(kafka_prefix: str): """Pick a random consumer group for kafka consumers on each call""" return "test-consumer-%s" % kafka_prefix
[docs]@pytest.fixture(scope="function") def object_types(): """Set of object types to precreate topics for.""" return set(TEST_OBJECTS.keys())
[docs]@pytest.fixture(scope="function") def privileged_object_types(): """Set of object types to precreate privileged topics for.""" return {"revision", "release"}
[docs]@pytest.fixture(scope="function") def kafka_server( kafka_server_base: str, kafka_prefix: str, object_types: Iterator[str], privileged_object_types: Iterator[str], ) -> str: """A kafka server with existing topics Unprivileged topics are built as ``{kafka_prefix}.{object_type}`` with object_type from the ``object_types`` list. Privileged topics are built as ``{kafka_prefix}_privileged.{object_type}`` with object_type from the ``privileged_object_types`` list. """ topics = [f"{kafka_prefix}.{obj}" for obj in object_types] + [ f"{kafka_prefix}_privileged.{obj}" for obj in privileged_object_types ] # unfortunately, the Mock broker does not support the CreatTopic admin API, so we # have to create topics using a Producer. producer = Producer( { "bootstrap.servers": kafka_server_base, "client.id": "bootstrap producer", "acks": "all", } ) for topic in topics: producer.produce(topic=topic, value=None) for i in range(10): if producer.flush(0.1) == 0: break return kafka_server_base
[docs]@pytest.fixture(scope="session") def kafka_server_base() -> Iterator[str]: """Create a mock kafka cluster suitable for tests. Yield a connection string. Note: this is a generator to keep the mock broker alive during the whole test session. see https://github.com/edenhill/librdkafka/blob/master/src/rdkafka_mock.h """ admin = AdminClient({"test.mock.num.brokers": "1"}) metadata = admin.list_topics() brokers = [str(broker) for broker in metadata.brokers.values()] assert len(brokers) == 1, "More than one broker found in the kafka cluster?!" broker_connstr, broker_id = brokers[0].split("/") yield broker_connstr
TEST_CONFIG = { "consumer_id": "swh.journal.consumer", "stop_after_objects": 1, # will read 1 object and stop "storage": {"cls": "memory", "args": {}}, }
[docs]@pytest.fixture def test_config( kafka_server_base: str, kafka_prefix: str, object_types: Iterator[str], privileged_object_types: Iterator[str], ): """Test configuration needed for producer/consumer """ return { **TEST_CONFIG, "object_types": object_types, "privileged_object_types": privileged_object_types, "brokers": [kafka_server_base], "prefix": kafka_prefix, }
[docs]@pytest.fixture def consumer( kafka_server: str, test_config: Dict, kafka_consumer_group: str ) -> Consumer: """Get a connected Kafka consumer. """ consumer = Consumer( { "bootstrap.servers": kafka_server, "auto.offset.reset": "earliest", "enable.auto.commit": True, "group.id": kafka_consumer_group, } ) prefix = test_config["prefix"] kafka_topics = [ f"{prefix}.{object_type}" for object_type in test_config["object_types"] ] + [ f"{prefix}_privileged.{object_type}" for object_type in test_config["privileged_object_types"] ] consumer.subscribe(kafka_topics) yield consumer consumer.close()