ms/blueprintsprocessor/modules/commons/message-lib/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/message/service/KafkaBasicAuthMessageConsumerService.kt

   1 /*
   2  *  Copyright © 2019 IBM.
   3  *
   4  *  Licensed under the Apache License, Version 2.0 (the "License");
   5  *  you may not use this file except in compliance with the License.
   6  *  You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  *  Unless required by applicable law or agreed to in writing, software
  11  *  distributed under the License is distributed on an "AS IS" BASIS,
  12  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  *  See the License for the specific language governing permissions and
  14  *  limitations under the License.
  15  */
  16
  17 package org.onap.ccsdk.cds.blueprintsprocessor.message.service
  18
  19 import kotlinx.coroutines.channels.Channel
  20 import kotlinx.coroutines.delay
  21 import kotlinx.coroutines.launch
  22 import kotlinx.coroutines.runBlocking
  23 import org.apache.kafka.clients.CommonClientConfigs
  24 import org.apache.kafka.clients.consumer.Consumer
  25 import org.apache.kafka.clients.consumer.ConsumerConfig
  26 import org.apache.kafka.clients.consumer.KafkaConsumer
  27 import org.apache.kafka.common.serialization.StringDeserializer
  28 import org.onap.ccsdk.cds.blueprintsprocessor.message.KafkaBasicAuthMessageConsumerProperties
  29 import org.onap.ccsdk.cds.controllerblueprints.core.logger
  30 import java.time.Duration
  31 import kotlin.concurrent.thread
  32
  33 class KafkaBasicAuthMessageConsumerService(
  34         private val messageConsumerProperties: KafkaBasicAuthMessageConsumerProperties)
  35     : BlueprintMessageConsumerService {
  36
  37     private val channel = Channel<String>()
  38     private var kafkaConsumer: Consumer<String, String>? = null
  39     val log = logger(KafkaBasicAuthMessageConsumerService::class)
  40
  41     @Volatile
  42     var keepGoing = true
  43
  44     fun kafkaConsumer(additionalConfig: Map<String, Any>? = null): Consumer<String, String> {
  45         val configProperties = hashMapOf<String, Any>()
  46         configProperties[CommonClientConfigs.BOOTSTRAP_SERVERS_CONFIG] = messageConsumerProperties.bootstrapServers
  47         configProperties[ConsumerConfig.GROUP_ID_CONFIG] = messageConsumerProperties.groupId
  48         configProperties[ConsumerConfig.AUTO_OFFSET_RESET_CONFIG] = "latest"
  49         configProperties[ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG] = StringDeserializer::class.java
  50         configProperties[ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG] = StringDeserializer::class.java
  51         if (messageConsumerProperties.clientId != null) {
  52             configProperties[ConsumerConfig.CLIENT_ID_CONFIG] = messageConsumerProperties.clientId!!
  53         }
  54         /** To handle Back pressure, Get only configured record for processing */
  55         if (messageConsumerProperties.pollRecords > 0) {
  56             configProperties[ConsumerConfig.MAX_POLL_RECORDS_CONFIG] = messageConsumerProperties.pollRecords
  57         }
  58         // TODO("Security Implementation based on type")
  59         /** add or override already set properties */
  60         additionalConfig?.let { configProperties.putAll(it) }
  61         /** Create Kafka consumer */
  62         return KafkaConsumer(configProperties)
  63     }
  64
  65     override suspend fun subscribe(additionalConfig: Map<String, Any>?): Channel<String> {
  66         /** get to topic names */
  67         val consumerTopic = messageConsumerProperties.topic?.split(",")?.map { it.trim() }
  68         check(!consumerTopic.isNullOrEmpty()) { "couldn't get topic information" }
  69         return subscribe(consumerTopic, additionalConfig)
  70     }
  71
  72
  73     override suspend fun subscribe(consumerTopic: List<String>, additionalConfig: Map<String, Any>?): Channel<String> {
  74         /** Create Kafka consumer */
  75         kafkaConsumer = kafkaConsumer(additionalConfig)
  76
  77         checkNotNull(kafkaConsumer) {
  78             "failed to create kafka consumer for " +
  79                     "server(${messageConsumerProperties.bootstrapServers})'s " +
  80                     "topics(${messageConsumerProperties.bootstrapServers})"
  81         }
  82
  83         kafkaConsumer!!.subscribe(consumerTopic)
  84         log.info("Successfully consumed topic($consumerTopic)")
  85
  86         thread(start = true, name = "KafkaConsumer") {
  87             keepGoing = true
  88             kafkaConsumer!!.use { kc ->
  89                 while (keepGoing) {
  90                     val consumerRecords = kc.poll(Duration.ofMillis(messageConsumerProperties.pollMillSec))
  91                     log.info("Consumed Records : ${consumerRecords.count()}")
  92                     runBlocking {
  93                         consumerRecords?.forEach { consumerRecord ->
  94                             /** execute the command block */
  95                             consumerRecord.value()?.let {
  96                                 launch {
  97                                     if (!channel.isClosedForSend) {
  98                                         channel.send(it)
  99                                     } else {
 100                                         log.error("Channel is closed to receive message")
 101                                     }
 102                                 }
 103                             }
 104                         }
 105                     }
 106                 }
 107                 log.info("message listener shutting down.....")
 108             }
 109         }
 110         return channel
 111     }
 112
 113     override suspend fun shutDown() {
 114         /** stop the polling loop */
 115         keepGoing = false
 116         /** Close the Channel */
 117         channel.cancel()
 118         /** TO shutdown gracefully, need to wait for the maximum poll time */
 119         delay(messageConsumerProperties.pollMillSec)
 120     }
 121 }