hunyadi-dev commented on a change in pull request #940: URL: https://github.com/apache/nifi-minifi-cpp/pull/940#discussion_r553170430
########## File path: extensions/librdkafka/ConsumeKafka.cpp ########## @@ -0,0 +1,553 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (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 + * + * Unless required by applicable law or agreed to in writing, 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. + */ + +#include "ConsumeKafka.h" + +#include <algorithm> +#include <limits> + +#include "core/PropertyValidation.h" +#include "utils/ProcessorConfigUtils.h" +#include "utils/gsl.h" + +namespace org { +namespace apache { +namespace nifi { +namespace minifi { +namespace core { +// The upper limit for Max Poll Time is 4 seconds. This is because Watchdog would potentially start +// reporting issues with the processor health otherwise +class ConsumeKafkaMaxPollTimeValidator : public TimePeriodValidator { + public: + ConsumeKafkaMaxPollTimeValidator(const std::string &name) // NOLINT + : TimePeriodValidator(name) { + } + ~ConsumeKafkaMaxPollTimeValidator() override = default; + + ValidationResult validate(const std::string& subject, const std::string& input) const override { + uint64_t value; + TimeUnit timeUnit; + uint64_t value_as_ms; + return ValidationResult::Builder::createBuilder().withSubject(subject).withInput(input).isValid( + core::TimePeriodValue::StringToTime(input, value, timeUnit) && + org::apache::nifi::minifi::core::Property::ConvertTimeUnitToMS(value, timeUnit, value_as_ms) && + 0 < value_as_ms && value_as_ms <= 4000).build(); + } +}; +} // namespace core +namespace processors { + +constexpr const std::size_t ConsumeKafka::DEFAULT_MAX_POLL_RECORDS; +constexpr char const* ConsumeKafka::DEFAULT_MAX_POLL_TIME; + +constexpr char const* ConsumeKafka::TOPIC_FORMAT_NAMES; +constexpr char const* ConsumeKafka::TOPIC_FORMAT_PATTERNS; + +core::Property ConsumeKafka::KafkaBrokers(core::PropertyBuilder::createProperty("Kafka Brokers") + ->withDescription("A comma-separated list of known Kafka Brokers in the format <host>:<port>.") + ->withDefaultValue("localhost:9092", core::StandardValidators::get().NON_BLANK_VALIDATOR) + ->supportsExpressionLanguage(true) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::SecurityProtocol(core::PropertyBuilder::createProperty("Security Protocol") + ->withDescription("This property is currently not supported. Protocol used to communicate with brokers. Corresponds to Kafka's 'security.protocol' property.") + ->withAllowableValues<std::string>({SECURITY_PROTOCOL_PLAINTEXT/*, SECURITY_PROTOCOL_SSL, SECURITY_PROTOCOL_SASL_PLAINTEXT, SECURITY_PROTOCOL_SASL_SSL*/ }) + ->withDefaultValue(SECURITY_PROTOCOL_PLAINTEXT) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::TopicNames(core::PropertyBuilder::createProperty("Topic Names") + ->withDescription("The name of the Kafka Topic(s) to pull from. Multiple topic names are supported as a comma separated list.") + ->supportsExpressionLanguage(true) + ->build()); + +core::Property ConsumeKafka::TopicNameFormat(core::PropertyBuilder::createProperty("Topic Name Format") + ->withDescription("Specifies whether the Topic(s) provided are a comma separated list of names or a single regular expression.") + ->withAllowableValues<std::string>({TOPIC_FORMAT_NAMES, TOPIC_FORMAT_PATTERNS}) + ->withDefaultValue(TOPIC_FORMAT_NAMES) + ->build()); + +core::Property ConsumeKafka::HonorTransactions(core::PropertyBuilder::createProperty("Honor Transactions") + ->withDescription( + "Specifies whether or not MiNiFi should honor transactional guarantees when communicating with Kafka. If false, the Processor will use an \"isolation level\" of " + "read_uncomitted. This means that messages will be received as soon as they are written to Kafka but will be pulled, even if the producer cancels the transactions. " + "If this value is true, MiNiFi will not receive any messages for which the producer's transaction was canceled, but this can result in some latency since the consumer " + "must wait for the producer to finish its entire transaction instead of pulling as the messages become available.") + ->withDefaultValue<bool>(true) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::GroupID(core::PropertyBuilder::createProperty("Group ID") + ->withDescription("A Group ID is used to identify consumers that are within the same consumer group. Corresponds to Kafka's 'group.id' property.") + ->supportsExpressionLanguage(true) + ->build()); + +core::Property ConsumeKafka::OffsetReset(core::PropertyBuilder::createProperty("Offset Reset") + ->withDescription("Allows you to manage the condition when there is no initial offset in Kafka or if the current offset does not exist any more on the server (e.g. because that " + "data has been deleted). Corresponds to Kafka's 'auto.offset.reset' property.") + ->withAllowableValues<std::string>({OFFSET_RESET_EARLIEST, OFFSET_RESET_LATEST, OFFSET_RESET_NONE}) + ->withDefaultValue(OFFSET_RESET_LATEST) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::KeyAttributeEncoding(core::PropertyBuilder::createProperty("Key Attribute Encoding") + ->withDescription("FlowFiles that are emitted have an attribute named 'kafka.key'. This property dictates how the value of the attribute should be encoded.") + ->withAllowableValues<std::string>({KEY_ATTR_ENCODING_UTF_8, KEY_ATTR_ENCODING_HEX}) + ->withDefaultValue(KEY_ATTR_ENCODING_UTF_8) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::MessageDemarcator(core::PropertyBuilder::createProperty("Message Demarcator") + ->withDescription("Since KafkaConsumer receives messages in batches, you have an option to output FlowFiles which contains all Kafka messages in a single batch " + "for a given topic and partition and this property allows you to provide a string (interpreted as UTF-8) to use for demarcating apart multiple Kafka messages. " + "This is an optional property and if not provided each Kafka message received will result in a single FlowFile which time it is triggered. ") + ->supportsExpressionLanguage(true) + ->build()); + +core::Property ConsumeKafka::MessageHeaderEncoding(core::PropertyBuilder::createProperty("Message Header Encoding") + ->withDescription("Any message header that is found on a Kafka message will be added to the outbound FlowFile as an attribute. This property indicates the Character Encoding " + "to use for deserializing the headers.") + ->withAllowableValues<std::string>({MSG_HEADER_ENCODING_UTF_8, MSG_HEADER_ENCODING_HEX}) + ->withDefaultValue(MSG_HEADER_ENCODING_UTF_8) + ->build()); + +core::Property ConsumeKafka::HeadersToAddAsAttributes(core::PropertyBuilder::createProperty("Headers To Add As Attributes") + ->withDescription("A Regular Expression that is matched against all message headers. Any message header whose name matches the regex will be added to the FlowFile " + "as an Attribute. If not specified, no Header values will be added as FlowFile attributes. If two messages have a different value for the same header and that " + "header is selected by the provided regex, then those two messages must be added to different FlowFiles. As a result, users should be cautious about using a " + "regex like \".*\" if messages are expected to have header values that are unique per message, such as an identifier or timestamp, because it will prevent MiNiFi " + "from bundling the messages together efficiently.") + ->build()); + +core::Property ConsumeKafka::DuplicateHeaderHandling(core::PropertyBuilder::createProperty("Duplicate Header Handling") + ->withDescription("For headers to be added as attributes, this option specifies how to handle cases where multiple headers are present with the same key. " + "For example in case of receiving these two headers: \"Accept: text/html\" and \"Accept: application/xml\" and we want to attach the value of \"Accept\" " + "as a FlowFile attribute:\n" + " - \"Keep First\" attaches: \"Accept -> text/html\"\n" + " - \"Keep Latest\" attaches: \"Accept -> application/xml\"\n" + " - \"Comma-separated Merge\" attaches: \"Accept -> text/html, application/xml\"\n") + ->withAllowableValues<std::string>({MSG_HEADER_KEEP_FIRST, MSG_HEADER_KEEP_LATEST, MSG_HEADER_COMMA_SEPARATED_MERGE}) + ->withDefaultValue(MSG_HEADER_KEEP_LATEST) // Mirroring NiFi behaviour + ->build()); + +core::Property ConsumeKafka::MaxPollRecords(core::PropertyBuilder::createProperty("Max Poll Records") + ->withDescription("Specifies the maximum number of records Kafka should return when polling each time the processor is triggered.") + ->withDefaultValue<unsigned int>(DEFAULT_MAX_POLL_RECORDS) + ->build()); + +core::Property ConsumeKafka::MaxPollTime(core::PropertyBuilder::createProperty("Max Poll Time") + ->withDescription("Specifies the maximum amount of time the consumer can use for polling data from the brokers. " + "Polling is a blocking operation, so the upper limit of this value is specified in 4 seconds.") + ->withDefaultValue(DEFAULT_MAX_POLL_TIME, std::make_shared<core::ConsumeKafkaMaxPollTimeValidator>(std::string("ConsumeKafkaMaxPollTimeValidator"))) + ->isRequired(true) + ->build()); + +core::Property ConsumeKafka::SessionTimeout(core::PropertyBuilder::createProperty("Session Timeout") + ->withDescription("Client group session and failure detection timeout. The consumer sends periodic heartbeats " + "to indicate its liveness to the broker. If no hearts are received by the broker for a group member within " + "the session timeout, the broker will remove the consumer from the group and trigger a rebalance. " + "The allowed range is configured with the broker configuration properties group.min.session.timeout.ms and group.max.session.timeout.ms.") + ->withDefaultValue<core::TimePeriodValue>("60 seconds") + ->build()); + +const core::Relationship ConsumeKafka::Success("success", "Incoming kafka messages as flowfiles. Depending on the demarcation strategy, this can be one or multiple flowfiles per message."); + +void ConsumeKafka::initialize() { + setSupportedProperties({ + KafkaBrokers, + SecurityProtocol, + TopicNames, + TopicNameFormat, + HonorTransactions, + GroupID, + OffsetReset, + KeyAttributeEncoding, + MessageDemarcator, + MessageHeaderEncoding, + HeadersToAddAsAttributes, + DuplicateHeaderHandling, + MaxPollRecords, + MaxPollTime, + SessionTimeout + }); + setSupportedRelationships({ + Success, + }); +} + +void ConsumeKafka::onSchedule(core::ProcessContext* context, core::ProcessSessionFactory* /* sessionFactory */) { + // Required properties + kafka_brokers_ = utils::getRequiredPropertyOrThrow(context, KafkaBrokers.getName()); + security_protocol_ = utils::getRequiredPropertyOrThrow(context, SecurityProtocol.getName()); + topic_names_ = utils::listFromRequiredCommaSeparatedProperty(context, TopicNames.getName()); + topic_name_format_ = utils::getRequiredPropertyOrThrow(context, TopicNameFormat.getName()); + honor_transactions_ = utils::parseBooleanPropertyOrThrow(context, HonorTransactions.getName()); + group_id_ = utils::getRequiredPropertyOrThrow(context, GroupID.getName()); + offset_reset_ = utils::getRequiredPropertyOrThrow(context, OffsetReset.getName()); + key_attribute_encoding_ = utils::getRequiredPropertyOrThrow(context, KeyAttributeEncoding.getName()); + max_poll_time_milliseconds_ = utils::parseTimePropertyMSOrThrow(context, MaxPollTime.getName()); + session_timeout_milliseconds_ = utils::parseTimePropertyMSOrThrow(context, SessionTimeout.getName()); + + // Optional properties + context->getProperty(MessageDemarcator.getName(), message_demarcator_); + context->getProperty(MessageHeaderEncoding.getName(), message_header_encoding_); + context->getProperty(DuplicateHeaderHandling.getName(), duplicate_header_handling_); + + headers_to_add_as_attributes_ = utils::listFromCommaSeparatedProperty(context, HeadersToAddAsAttributes.getName()); + max_poll_records_ = gsl::narrow<std::size_t>(utils::getOptionalUintProperty(context, MaxPollRecords.getName()).value_or(DEFAULT_MAX_POLL_RECORDS)); + + // For now security protocols are not yet supported + if (!utils::StringUtils::equalsIgnoreCase(SECURITY_PROTOCOL_PLAINTEXT, security_protocol_)) { + throw Exception(PROCESS_SCHEDULE_EXCEPTION, "Security protocols are not supported yet."); + } + + if (!utils::StringUtils::equalsIgnoreCase(KEY_ATTR_ENCODING_UTF_8, key_attribute_encoding_) && !utils::StringUtils::equalsIgnoreCase(KEY_ATTR_ENCODING_HEX, key_attribute_encoding_)) { + throw Exception(PROCESS_SCHEDULE_EXCEPTION, "Unsupported key attribute encoding: " + key_attribute_encoding_); + } + + if (!utils::StringUtils::equalsIgnoreCase(MSG_HEADER_ENCODING_UTF_8, message_header_encoding_) && !utils::StringUtils::equalsIgnoreCase(MSG_HEADER_ENCODING_HEX, message_header_encoding_)) { + throw Exception(PROCESS_SCHEDULE_EXCEPTION, "Unsupported message header encoding: " + key_attribute_encoding_); + } + + configure_new_connection(context); +} + +void rebalance_cb(rd_kafka_t* rk, rd_kafka_resp_err_t trigger, rd_kafka_topic_partition_list_t* partitions, void* /*opaque*/) { Review comment: Updated. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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