Expose Prometheus metrics

Expose both JVM and HV-VES metrics by means of HealthCheckApiServer in
Prometheus format.

Change-Id: I81b74cd945c67569703a4a74f5a2683ede18d64a
Issue-ID: DCAEGEN2-1029
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
index ac282008..aead71bb 100644
--- a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
+++ b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
@@ -23,6 +23,7 @@ import arrow.effects.IO
 import io.netty.handler.codec.http.HttpResponseStatus
 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthDescription
 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthState
+import org.onap.dcae.collectors.veshv.healthcheck.ports.PrometheusMetricsProvider
 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
@@ -39,6 +40,7 @@ import java.util.concurrent.atomic.AtomicReference
  * @since August 2018
  */
 class HealthCheckApiServer(private val healthState: HealthState,
+                           private val monitoring: PrometheusMetricsProvider,
                            private val listenAddress: SocketAddress) {
 
     private val healthDescription: AtomicReference<HealthDescription> = AtomicReference(HealthDescription.STARTING)
@@ -50,6 +52,7 @@ class HealthCheckApiServer(private val healthState: HealthState,
                 .route { routes ->
                     routes.get("/health/ready", ::readinessHandler)
                     routes.get("/health/alive", ::livenessHandler)
+                    routes.get("/monitoring/prometheus", ::monitoringHandler)
                 }
         NettyServerHandle(ctx.bindNow())
     }
@@ -63,6 +66,10 @@ class HealthCheckApiServer(private val healthState: HealthState,
     private fun livenessHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
             resp.status(HttpResponseStatus.NOT_IMPLEMENTED).sendString(Mono.just("Not implemented yet"))
 
+
+    private fun monitoringHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
+            resp.sendString(monitoring.lastStatus())
+
     companion object {
         private val logger = Logger(HealthCheckApiServer::class)
     }
diff --git a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt
new file mode 100644
index 00000000..c5018759
--- /dev/null
+++ b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt
@@ -0,0 +1,30 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 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.healthcheck.ports
+
+import reactor.core.publisher.Mono
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since December 2018
+ */
+interface PrometheusMetricsProvider {
+    fun lastStatus(): Mono<String>
+}