sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt

   1 /*
   2  * ============LICENSE_START=======================================================
   3  * dcaegen2-collectors-veshv
   4  * ================================================================================
   5  * Copyright (C) 2018-2019 NOKIA
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20 package org.onap.dcae.collectors.veshv.healthcheck.factory
  21
  22 import arrow.effects.IO
  23 import io.netty.handler.codec.http.HttpResponseStatus
  24 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthDescription
  25 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthState
  26 import org.onap.dcae.collectors.veshv.healthcheck.ports.PrometheusMetricsProvider
  27 import org.onap.dcae.collectors.veshv.utils.NettyServerHandle
  28 import org.onap.dcae.collectors.veshv.utils.ServerHandle
  29 import org.onap.dcae.collectors.veshv.utils.logging.Logger
  30 import reactor.core.publisher.Flux
  31 import reactor.core.publisher.Mono
  32 import reactor.netty.http.server.HttpServer
  33 import reactor.netty.http.server.HttpServerRequest
  34 import reactor.netty.http.server.HttpServerResponse
  35 import java.net.SocketAddress
  36 import java.util.concurrent.atomic.AtomicReference
  37
  38 /**
  39  * @author Jakub Dudycz <jakub.dudycz@nokia.com>
  40  * @since August 2018
  41  */
  42 class HealthCheckApiServer(private val healthState: HealthState,
  43                            private val monitoring: PrometheusMetricsProvider,
  44                            private val listenAddress: SocketAddress) {
  45
  46     private val healthDescription: AtomicReference<HealthDescription> = AtomicReference(HealthDescription.STARTING)
  47
  48     fun start(): IO<ServerHandle> = IO {
  49         healthState().subscribe(healthDescription::set)
  50         val ctx = HttpServer.create()
  51                 .tcpConfiguration {
  52                     it.addressSupplier { listenAddress }
  53                             .doOnUnbound { logClose() }
  54                 }
  55                 .route { routes ->
  56                     routes.get("/health/ready", ::readinessHandler)
  57                     routes.get("/health/alive", ::livenessHandler)
  58                     routes.get("/monitoring/prometheus", ::monitoringHandler)
  59                 }
  60         NettyServerHandle(ctx.bindNow())
  61     }
  62
  63     private fun readinessHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
  64             healthDescription.get().run {
  65                 logger.debug { "Component status: $status, $message" }
  66                 resp.status(status.httpResponseStatus.number).sendString(Flux.just(status.toString(), "\n", message))
  67             }
  68
  69     private fun livenessHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
  70             resp.status(HttpResponseStatus.NOT_IMPLEMENTED).sendString(Mono.just("Not implemented yet"))
  71
  72
  73     private fun monitoringHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
  74             resp.sendString(monitoring.lastStatus())
  75
  76     private fun logClose() {
  77         logger.info { "Health Check API closed" }
  78     }
  79
  80     companion object {
  81         private val logger = Logger(HealthCheckApiServer::class)
  82
  83     }
  84
  85 }