Implement blocking consul calls

Replaced interval based requesting for consul configuration with blocking query calls

Closes ONAP-80

Change-Id: If70365bae9fde513d99b047209d085122a5df0dd
Signed-off-by: Jakub Dudycz <jdudycz@nokia.com>
Issue-ID: DCAEGEN2-601

6 files changed, 138 insertions, 62 deletions

diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/AdapterFactory.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/AdapterFactory.kt
index d9e7432d..2a8a3960 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/AdapterFactory.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/AdapterFactory.kt
@@ -33,8 +33,8 @@ object AdapterFactory {
     fun kafkaSink(): SinkProvider = KafkaSinkProvider()
     fun loggingSink(): SinkProvider = LoggingSinkProvider()
 
-    fun consulConfigurationProvider(url: String, updateInterval: Duration): ConfigurationProvider =
-            ConsulConfigurationProvider(url, updateInterval, httpAdapter())
+    fun consulConfigurationProvider(url: String, firstRequestDelay: Duration): ConfigurationProvider =
+            ConsulConfigurationProvider(url, httpAdapter(), firstRequestDelay)
 
     fun httpAdapter(): HttpAdapter = HttpAdapter(HttpClient.create())
 }
diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProvider.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProvider.kt
index c70d128a..727f025b 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProvider.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProvider.kt
@@ -26,9 +26,14 @@ import org.onap.ves.VesEventV5.VesEvent.CommonEventHeader.Domain.HVRANMEAS
 import org.onap.ves.VesEventV5.VesEvent.CommonEventHeader.Domain.forNumber
 import org.slf4j.LoggerFactory
 import reactor.core.publisher.Flux
+import reactor.core.publisher.Mono
+import reactor.ipc.netty.http.client.HttpClientException
+import reactor.retry.Retry
+import reactor.retry.retryExponentialBackoff
 import java.io.StringReader
 import java.time.Duration
-import java.util.Base64
+import java.util.*
+import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicReference
 import javax.json.Json
 import javax.json.JsonObject
@@ -39,18 +44,17 @@ import javax.json.JsonObject
  * @since May 2018
  */
 internal class ConsulConfigurationProvider(private val url: String,
-                                           private val updateInterval: Duration,
-                                           private val http: HttpAdapter
+                                           private val http: HttpAdapter,
+                                           private val firstRequestDelay: Duration
 ) : ConfigurationProvider {
 
-
-    private val logger = LoggerFactory.getLogger(ConsulConfigurationProvider::class.java)
-    private var lastConfigurationHash: AtomicReference<Int> = AtomicReference()
+    private val lastModifyIndex: AtomicReference<Int> = AtomicReference(0)
+    private val lastConfigurationHash: AtomicReference<Int> = AtomicReference(0)
 
     override fun invoke(): Flux<CollectorConfiguration> =
             Flux.concat(createDefaultConfigurationFlux(), createConsulFlux())
 
-    private fun createDefaultConfigurationFlux(): Flux<CollectorConfiguration> = Flux.just(
+    private fun createDefaultConfigurationFlux(): Mono<CollectorConfiguration> = Mono.just(
             CollectorConfiguration(
                     kafkaBootstrapServers = "kafka:9092",
                     routing = routing {
@@ -60,22 +64,45 @@ internal class ConsulConfigurationProvider(private val url: String,
                             withFixedPartitioning()
                         }
                     }.build())
-    ).doOnNext { logger.info("Applied default configuration") }
-
-    private fun createConsulFlux(): Flux<CollectorConfiguration> = Flux.interval(updateInterval)
-            .flatMap { http.get(url) }
-            .doOnError { logger.error("Encountered an error when trying to acquire configuration from consul. " +
-                    "Shutting down..") }
-            .filter { it.hashCode() != lastConfigurationHash.get() }
-            .doOnNext { lastConfigurationHash.set(it.hashCode()) }
-            .map { getConfigurationJson(it) }
-            .map { createCollectorConfiguration(it) }
-
-
-    private fun getConfigurationJson(str: String): JsonObject {
-        val response = Json.createReader(StringReader(str)).readArray().getJsonObject(0)
-        val decodedValue = String(
-                Base64.getDecoder().decode(response.getString("Value")))
+    ).doOnNext { logger.info("Applied default configuration") }.delayElement(firstRequestDelay)
+
+    private fun createConsulFlux(): Flux<CollectorConfiguration> =
+            http.get(url, mapOf(Pair("index", lastModifyIndex.get())))
+                    .doOnError {
+                        logger.error("Encountered an error " +
+                                "when trying to acquire configuration from consul. Shutting down..")
+                    }
+                    .map(::parseJsonResponse)
+                    .doOnNext(::updateModifyIndex)
+                    .map(::extractEncodedConfiguration)
+                    .flatMap(::filterDifferentValues)
+                    .map(::decodeConfiguration)
+                    .map(::createCollectorConfiguration)
+                    .repeat()
+
+    private fun parseJsonResponse(responseString: String): JsonObject =
+            Json.createReader(StringReader(responseString)).readArray().first().asJsonObject()
+
+    private fun updateModifyIndex(response: JsonObject) =
+            lastModifyIndex.set(response.getInt("ModifyIndex"))
+
+    private fun extractEncodedConfiguration(response: JsonObject): String =
+            response.getString("Value")
+
+    private fun filterDifferentValues(base64Value: String): Mono<String> {
+        val newHash = hashOf(base64Value)
+        return if (newHash == lastConfigurationHash.get()) {
+            Mono.empty()
+        } else {
+            lastConfigurationHash.set(newHash)
+            Mono.just(base64Value)
+        }
+    }
+
+    private fun hashOf(str: String) = str.hashCode()
+
+    private fun decodeConfiguration(encodedConfiguration: String): JsonObject {
+        val decodedValue = String(Base64.getDecoder().decode(encodedConfiguration))
         logger.info("Obtained new configuration from consul:\n$decodedValue")
         return Json.createReader(StringReader(decodedValue)).readObject()
     }
@@ -97,5 +124,9 @@ internal class ConsulConfigurationProvider(private val url: String,
                 }.build()
         )
     }
+
+    companion object {
+        private val logger = LoggerFactory.getLogger(ConsulConfigurationProvider::class.java)
+    }
 }
 
diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapter.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapter.kt
index a41cd09f..4503955f 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapter.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapter.kt
@@ -23,7 +23,6 @@ import org.slf4j.LoggerFactory
 import reactor.core.publisher.Mono
 import reactor.core.publisher.toMono
 import reactor.ipc.netty.http.client.HttpClient
-import reactor.ipc.netty.http.client.HttpClientResponse
 import java.nio.charset.Charset
 
 /**
@@ -34,12 +33,31 @@ open class HttpAdapter(private val httpClient: HttpClient) {
 
     private val logger = LoggerFactory.getLogger(HttpAdapter::class.java)
 
-    open fun get(url: String): Mono<String> =
-            httpClient.get(url)
-                    .doOnError {
-                        logger.error("Failed to get resource on path: $url (${it.localizedMessage})")
-                        logger.debug("Nested exception:", it)
-                    }
-                    .flatMap { it.receiveContent().toMono() }
-                    .map { it.content().toString(Charset.defaultCharset()) }
+    open fun get(url: String, queryParams: Map<String, Any> = emptyMap()): Mono<String> = httpClient
+            .get(url + createQueryString(queryParams))
+            .doOnError {
+                logger.error("Failed to get resource on path: $url (${it.localizedMessage})")
+                logger.debug("Nested exception:", it)
+            }
+            .flatMap { it.receiveContent().toMono() }
+            .map { it.content().toString(Charset.defaultCharset()) }
+
+
+    private fun createQueryString(params: Map<String, Any>): String {
+        if (params.isEmpty())
+            return ""
+
+        val builder = StringBuilder("?")
+        params.forEach { (key, value) ->
+            builder
+                    .append(key)
+                    .append("=")
+                    .append(value)
+                    .append("&")
+
+        }
+
+        return  builder.removeSuffix("&").toString()
+    }
+
 }
diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/model/ServerConfiguration.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/model/ServerConfiguration.kt
index 025c59f6..a486996e 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/model/ServerConfiguration.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/model/ServerConfiguration.kt
@@ -29,7 +29,7 @@ import java.time.Duration
 data class ServerConfiguration(
         val port: Int,
         val configurationUrl: String,
-        val configurationUpdateInterval: Duration,
+        val firstRequestDelay: Duration,
         val securityConfiguration: SecurityConfiguration,
         val idleTimeout: Duration,
         val dummyMode: Boolean = false)
diff --git a/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProviderTest.kt b/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProviderTest.kt
index dd190848..c98c97a6 100644
--- a/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProviderTest.kt
+++ b/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/ConsulConfigurationProviderTest.kt
@@ -19,12 +19,14 @@
  */
 package org.onap.dcae.collectors.veshv.impl.adapters
 
+import com.nhaarman.mockito_kotlin.eq
 import com.nhaarman.mockito_kotlin.mock
 import com.nhaarman.mockito_kotlin.verify
 import com.nhaarman.mockito_kotlin.whenever
 import org.jetbrains.spek.api.Spek
 import org.jetbrains.spek.api.dsl.given
 import org.jetbrains.spek.api.dsl.it
+import org.mockito.Mockito
 import org.onap.ves.VesEventV5.VesEvent.CommonEventHeader.Domain
 import reactor.core.publisher.Mono
 import reactor.ipc.netty.http.client.HttpClient
@@ -39,15 +41,16 @@ import kotlin.test.assertEquals
  */
 internal object ConsulConfigurationProviderTest : Spek({
 
-    val updateInterval = Duration.ofMillis(1)
     val httpAdapterMock: HttpAdapter = mock()
+    val firstRequestDelay = Duration.ofMillis(1)
 
     given("valid resource url") {
 
         val validUrl = "http://valid-url/"
-        val consulConfigProvider = ConsulConfigurationProvider(validUrl, updateInterval, httpAdapterMock)
+        val consulConfigProvider = ConsulConfigurationProvider(validUrl, httpAdapterMock, firstRequestDelay)
 
-        whenever(httpAdapterMock.get(validUrl)).thenReturn(Mono.just(constructConsulResponse()))
+        whenever(httpAdapterMock.get(eq(validUrl), Mockito.anyMap()))
+                .thenReturn(Mono.just(constructConsulResponse()))
 
         it("should use default configuration at the beginning, " +
                 "then apply received configuration") {
@@ -79,9 +82,10 @@ internal object ConsulConfigurationProviderTest : Spek({
     given("invalid resource url") {
 
         val invalidUrl = "http://invalid-url/"
-        val consulConfigProvider = ConsulConfigurationProvider(invalidUrl, updateInterval, httpAdapterMock)
+        val consulConfigProvider = ConsulConfigurationProvider(invalidUrl, httpAdapterMock, firstRequestDelay)
 
-        whenever(httpAdapterMock.get(invalidUrl)).thenReturn(Mono.error(RuntimeException("Test exception")))
+        whenever(httpAdapterMock.get(eq(invalidUrl), Mockito.anyMap()))
+                .thenReturn(Mono.error(RuntimeException("Test exception")))
 
         it("should use default configuration at the beginning, then should interrupt the flux") {
 
diff --git a/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapterTest.kt b/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapterTest.kt
index 79eda995..123d8f72 100644
--- a/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapterTest.kt
+++ b/hv-collector-core/src/test/kotlin/org/onap/dcae/collectors/veshv/impl/adapters/HttpAdapterTest.kt
@@ -20,10 +20,12 @@
 package org.onap.dcae.collectors.veshv.impl.adapters
 
 import com.nhaarman.mockito_kotlin.mock
+import com.nhaarman.mockito_kotlin.verify
 import com.nhaarman.mockito_kotlin.whenever
 import io.netty.buffer.Unpooled
 import io.netty.handler.codec.http.HttpContent
 import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
 import org.jetbrains.spek.api.dsl.given
 import org.jetbrains.spek.api.dsl.it
 import reactor.core.publisher.Flux
@@ -32,44 +34,65 @@ import reactor.ipc.netty.http.client.HttpClient
 import reactor.ipc.netty.http.client.HttpClientResponse
 import reactor.test.StepVerifier
 import java.nio.charset.Charset
-import kotlin.test.assertEquals
 
 /**
  * @author Jakub Dudycz <jakub.dudycz@nokia.com>
  * @since May 2018
  */
 internal object HttpAdapterTest : Spek({
-
-    given("valid resource url") {
+    describe("HttpAdapter") {
 
         val httpClientMock: HttpClient = mock()
         val httpAdapter = HttpAdapter(httpClientMock)
-        val validUrl = "http://valid-url/"
-        val responseContent = """{"key1": "value1", "key2": "value2"}"""
-        val httpResponse = createHttpResponseMock(responseContent)
-        whenever(httpClientMock.get(validUrl)).thenReturn(Mono.just(httpResponse))
 
-        it("should return response string") {
-            StepVerifier
-                    .create(httpAdapter.get(validUrl))
-                    .expectNext(responseContent)
+        given("url without query params") {
+            val initialUrl = "http://test-url"
+            whenever(httpClientMock.get(initialUrl)).thenReturn(Mono.empty())
+
+            it("should not append query string") {
+                httpAdapter.get(initialUrl)
+                verify(httpClientMock).get(initialUrl)
+            }
         }
-    }
 
-    given("invalid resource url") {
+        given("url with query params") {
+            val queryParams = mapOf(Pair("key", "value"))
+            val initialUrl = "http://test-url"
+            val expectedUrl = "http://test-url?key=value"
+            whenever(httpClientMock.get(expectedUrl)).thenReturn(Mono.empty())
 
-        val httpClientMock: HttpClient = mock()
-        val httpAdapter = HttpAdapter(httpClientMock)
-        val invalidUrl = "http://invalid-url/"
-        val exceptionMessage = "Test exception"
-        whenever(httpClientMock.get(invalidUrl)).thenReturn(Mono.error(Exception(exceptionMessage)))
+            it("should parse them to query string and append to url") {
+                httpAdapter.get(initialUrl, queryParams)
+                verify(httpClientMock).get(expectedUrl)
+            }
+        }
 
-        it("should interrupt the flux") {
-            StepVerifier
-                    .create(httpAdapter.get(invalidUrl))
-                    .verifyErrorMessage(exceptionMessage)
+        given("valid resource url") {
+            val validUrl = "http://valid-url/"
+            val responseContent = """{"key1": "value1", "key2": "value2"}"""
+            val httpResponse = createHttpResponseMock(responseContent)
+            whenever(httpClientMock.get(validUrl)).thenReturn(Mono.just(httpResponse))
+
+            it("should return response string") {
+                StepVerifier
+                        .create(httpAdapter.get(validUrl))
+                        .expectNext(responseContent)
+            }
+        }
+
+        given("invalid resource url") {
+            val invalidUrl = "http://invalid-url/"
+            val exceptionMessage = "Test exception"
+            whenever(httpClientMock.get(invalidUrl)).thenReturn(Mono.error(Exception(exceptionMessage)))
+
+            it("should interrupt the flux") {
+                StepVerifier
+                        .create(httpAdapter.get(invalidUrl))
+                        .verifyErrorMessage(exceptionMessage)
+            }
         }
     }
+
 })
 
 fun createHttpResponseMock(content: String): HttpClientResponse {