Expose Prometheus metrics in Kafka Consumer

Change-Id: I9d0568a5fc296604d7ac7a45b8bbd0289b845938
Signed-off-by: Jakub Dudycz <jakub.dudycz@nokia.com>
Issue-ID: DCAEGEN2-1626

7 files changed, 209 insertions, 3 deletions

diff --git a/sources/hv-collector-kafka-consumer/pom.xml b/sources/hv-collector-kafka-consumer/pom.xml
index 45a32729..1e20d5b1 100644
--- a/sources/hv-collector-kafka-consumer/pom.xml
+++ b/sources/hv-collector-kafka-consumer/pom.xml
@@ -90,6 +90,13 @@
       <artifactId>logback-classic</artifactId>
       <scope>runtime</scope>
     </dependency>
-
+    <dependency>
+      <groupId>io.micrometer</groupId>
+      <artifactId>micrometer-registry-prometheus</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.projectreactor.netty</groupId>
+      <artifactId>reactor-netty</artifactId>
+    </dependency>
   </dependencies>
 </project>
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/ArgKafkaConsumerConfiguration.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/ArgKafkaConsumerConfiguration.kt
new file mode 100644
index 00000000..4d65e916
--- /dev/null
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/ArgKafkaConsumerConfiguration.kt
@@ -0,0 +1,40 @@
+/*
+* ============LICENSE_START=======================================================
+* dcaegen2-collectors-veshv
+* ================================================================================
+* Copyright (C) 2019 NOKIA
+* ================================================================================
+* Licensed 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.
+* ============LICENSE_END=========================================================
+*/
+package org.onap.dcae.collectors.veshv.kafkaconsumer.config
+
+import arrow.core.Option
+import org.apache.commons.cli.CommandLine
+import org.apache.commons.cli.DefaultParser
+import org.onap.dcae.collectors.veshv.commandline.ArgBasedConfiguration
+import org.onap.dcae.collectors.veshv.commandline.CommandLineOption
+import org.onap.dcae.collectors.veshv.commandline.CommandLineOption.LISTEN_PORT
+import org.onap.dcae.collectors.veshv.commandline.intValue
+import org.onap.dcae.collectors.veshv.utils.arrow.OptionUtils.binding
+import java.net.InetSocketAddress
+
+internal class ArgKafkaConsumerConfiguration : ArgBasedConfiguration<KafkaConsumerConfiguration>(DefaultParser()) {
+    override val cmdLineOptionsList: List<CommandLineOption> = listOf(LISTEN_PORT)
+
+    override fun getConfiguration(cmdLine: CommandLine): Option<KafkaConsumerConfiguration> =
+            binding {
+                val listenPort = cmdLine.intValue(LISTEN_PORT).bind()
+                KafkaConsumerConfiguration(InetSocketAddress(listenPort))
+            }
+}
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/KafkaConsumerConfiguration.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/KafkaConsumerConfiguration.kt
new file mode 100644
index 00000000..ef06a0d1
--- /dev/null
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/config/KafkaConsumerConfiguration.kt
@@ -0,0 +1,24 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2019 NOKIA
+ * ================================================================================
+ * Licensed 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.kafkaconsumer.config
+
+import java.net.InetSocketAddress
+
+internal data class KafkaConsumerConfiguration(val apiAddress: InetSocketAddress)
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/main.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/main.kt
index fa15587c..7e77bae9 100644
--- a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/main.kt
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/main.kt
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * dcaegen2-collectors-veshv
  * ================================================================================
- * Copyright (C) 2018-2019 NOKIA
+ * Copyright (C) 2019 NOKIA
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,4 +19,26 @@
  */
 package org.onap.dcae.collectors.veshv.kafkaconsumer
 
-fun main(args: Array<String>) = println("Guten tag")
+import org.onap.dcae.collectors.veshv.commandline.handleWrongArgumentErrorCurried
+import org.onap.dcae.collectors.veshv.kafkaconsumer.config.ArgKafkaConsumerConfiguration
+import org.onap.dcae.collectors.veshv.kafkaconsumer.config.KafkaConsumerConfiguration
+import org.onap.dcae.collectors.veshv.kafkaconsumer.metrics.MicrometerMetrics
+import org.onap.dcae.collectors.veshv.kafkaconsumer.metrics.http.PrometheusApiServer
+import org.onap.dcae.collectors.veshv.utils.process.ExitCode
+import org.onap.dcae.collectors.veshv.utils.process.ExitSuccess
+
+private const val PACKAGE_NAME = "org.onap.dcae.collectors.veshv.kafkaconsumer"
+const val PROGRAM_NAME = "java $PACKAGE_NAME.MainKt"
+
+fun main(args: Array<String>): Unit =
+        ArgKafkaConsumerConfiguration().parse(args)
+                .fold(handleWrongArgumentErrorCurried(PROGRAM_NAME), ::startApp)
+                .let(ExitCode::doExit)
+
+
+private fun startApp(config: KafkaConsumerConfiguration): ExitSuccess {
+    PrometheusApiServer(config.apiAddress, MicrometerMetrics.INSTANCE)
+            .start().block()!!.await().block() // TODO refactor netty server logic
+
+    return ExitSuccess
+}
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/Metrics.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/Metrics.kt
new file mode 100644
index 00000000..cbdb45dc
--- /dev/null
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/Metrics.kt
@@ -0,0 +1,22 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2019 NOKIA
+ * ================================================================================
+ * Licensed 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.kafkaconsumer.metrics
+
+internal interface Metrics
\ No newline at end of file
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/MicrometerMetrics.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/MicrometerMetrics.kt
new file mode 100644
index 00000000..adb1ff1f
--- /dev/null
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/MicrometerMetrics.kt
@@ -0,0 +1,37 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2019 NOKIA
+ * ================================================================================
+ * Licensed 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.kafkaconsumer.metrics
+
+import io.micrometer.prometheus.PrometheusConfig
+import io.micrometer.prometheus.PrometheusMeterRegistry
+import reactor.core.publisher.Mono
+
+internal class MicrometerMetrics constructor(
+        private val registry: PrometheusMeterRegistry = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)
+) : Metrics {
+
+    fun lastStatus(): Mono<String> = Mono.fromCallable {
+        registry.scrape()
+    }
+
+    companion object {
+        val INSTANCE by lazy { MicrometerMetrics() }
+    }
+}
diff --git a/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/http/PrometheusApiServer.kt b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/http/PrometheusApiServer.kt
new file mode 100644
index 00000000..29a17fc1
--- /dev/null
+++ b/sources/hv-collector-kafka-consumer/src/main/kotlin/org/onap/dcae/collectors/veshv/kafkaconsumer/metrics/http/PrometheusApiServer.kt
@@ -0,0 +1,54 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2019 NOKIA
+ * ================================================================================
+ * Licensed 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.kafkaconsumer.metrics.http
+
+import org.onap.dcae.collectors.veshv.kafkaconsumer.metrics.MicrometerMetrics
+import org.onap.dcae.collectors.veshv.utils.NettyServerHandle
+import org.onap.dcae.collectors.veshv.utils.ServerHandle
+import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import reactor.core.publisher.Mono
+import reactor.netty.http.server.HttpServer
+import reactor.netty.http.server.HttpServerRequest
+import reactor.netty.http.server.HttpServerResponse
+import java.net.InetSocketAddress
+
+internal class PrometheusApiServer(private val listenAddress: InetSocketAddress,
+                                   private val metrics: MicrometerMetrics) {
+
+    private val logger = Logger(PrometheusApiServer::class)
+
+    fun start(): Mono<NettyServerHandle> =
+            HttpServer.create()
+                    .tcpConfiguration { it.addressSupplier { listenAddress } }
+                    .route { it.get("/monitoring/prometheus", ::metricsHandler) }
+                    .bind()
+                    .map { NettyServerHandle(it) }
+                    .doOnSuccess(::logServerStarted)
+
+
+    private fun metricsHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
+            resp.sendString(metrics.lastStatus())
+
+
+    private fun logServerStarted(handle: ServerHandle) =
+            logger.info {
+                "Kafka Consumer API server is up and listening on ${handle.host}:${handle.port}"
+            }
+}